HK1224091B - Laser tube with baffles - Google Patents

Description

Laser tube with baffle

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. 119(e) to U.S. Provisional Application No. 61/822,562, filed May 13, 2013, which is hereby incorporated by reference in its entirety.

Background Art

Lasers generate optical radiation (light) within a laser resonator (often called a laser cavity). The optical radiation accumulates within the laser resonator and eventually propagates through the resonator's final optical surface (often called an output coupler) to the outside of the laser. Powerful laser light can be used to cut, drill, weld, mark, or engrave materials. In particular, radio frequency (RF) excited gas lasers generate laser energy when the gas medium within the laser is excited by applying RF energy between a pair of electrodes. An example of a gas laser is a carbon dioxide ( _CO2 ) laser.

The performance parameters of a laser, particularly an RF-excited gas laser, can generally be characterized in terms of laser power, power stability, and beam mode quality. Each of these performance parameters may be affected by one or more conditions within the laser itself. For example, changing the gas conditions within the electrodes of an RF-excited gas laser may affect the uniformity of the gas discharge within the electrodes. This in turn may affect the ^M2 (pronounced "M squared") parameter, which is defined as the ratio of the beam parameter product (BPP) of the actual beam to the beam parameter product of an ideal Gaussian beam of the same wavelength (e.g., the "beam quality factor"). Changing the conditions of the gas within the electrodes may also affect other laser beam characteristics, such as ellipticity and/or roundness. In pulsed gas lasers, particularly where unstable resonators are used, acoustic oscillations within the laser structure may result in these altered conditions within the electrodes and, therefore, degrade the beam quality and/or degrade the power stability. As a result, the ability of the laser to effectively perform its intended purpose is often reduced.

Summary of the Invention

This Summary is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

Exemplary embodiments disclosed herein are directed to a tube for a slab laser. The tube includes a first electrode having a first electrode inner surface and a second electrode having a second electrode inner surface. The first electrode is spaced apart from the second electrode in a first lateral direction, thereby defining a gap region having a gap thickness between the first electrode inner surface and the second electrode inner surface. The tube also includes first and second elongated baffle members, each having an elongated central channel formed in its inner surface. The first and second elongated baffle members are positioned in the gap region along first and second longitudinal edge portions, respectively, of the first and second electrodes. The first and second elongated baffle members are positioned with their inner surfaces facing the gap region such that the first electrode, the second electrode, and the inner surfaces of the first and second baffle members cooperatively surround the gap region. The elongated central channel of the baffle members extends the gap region in a second lateral direction by the depth of the elongated central channel, thereby defining a stand-off region in the channel that extends longitudinally along the length of the baffle members.

Furthermore, various embodiments disclosed herein are directed to a tube for a slab laser, comprising a first electrode having a first electrode inner surface and a second electrode having a second electrode inner surface. The first electrode is spaced apart from the second electrode in a first lateral direction, thereby defining a gap region having a gap thickness between the first electrode inner surface and the second electrode inner surface. The tube includes first and second elongated baffle members, each having an elongated central channel formed in its inner surface. The first and second elongated baffle members are disposed in the gap region along first and second longitudinal edge portions, respectively, of the first and second electrodes. The first and second elongated baffle members are disposed with their inner surfaces facing the gap region such that the inner surfaces of the first electrode, the second electrode, the first baffle member, and the second baffle member cooperate to surround the gap region. The first and second elongated baffle members each include an aperture disposed longitudinally along their length.

Other aspects of the invention will become apparent from the ensuing description and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 shows a cross-sectional view of a prior art laser electrode structure using a spacer;

2A-2B illustrate cross-sectional views of laser electrode structures separated by baffles according to one or more embodiments of the present invention;

3A-3B illustrate expanded perspective views of laser electrode structures separated by baffles according to one or more embodiments of the present invention;

4A-4B illustrate an exploded perspective view of a laser resonator structure and a top view of the laser resonator, respectively, according to one or more embodiments of the present invention; and

5 shows a plot of the position of the laser beam (angular offset) versus the input RF pulse frequency to the laser (laser pulse frequency) when a baffle is used, in accordance with one or more embodiments of the present invention.

DETAILED DESCRIPTION

Now, a specific embodiment of a laser tube with a baffle will be described in detail with reference to the accompanying drawings. For the sake of uniformity, similar elements in various drawings (also referred to as drawings) are denoted by similar reference numerals.

In the following detailed description of the embodiments, numerous specific details are set forth to provide a more complete understanding of the laser tube with a baffle. However, it will be apparent to one skilled in the art that the embodiments can be practiced without these specific details. Furthermore, well-known features are not described in detail to avoid unnecessarily complicating the description.

In general, the present disclosure is directed to a radio frequency (RF) excited gas discharge laser (e.g., a slab laser). The laser comprises an enclosure containing the laser gas, wherein a pair of elongated planar electrodes are disposed within the enclosure and spaced apart to define a narrow gap corresponding to the discharge region. A laser resonator is defined by placing reflectors at the ends of the electrodes. The electrodes form a waveguide or light guide along one axis of the resonator and define the lasing mode of the resonator along an axis perpendicular to the plane of the electrodes (the waveguide axis). The reflectors define the lasing mode along an axis parallel to the plane of the electrodes. This type of reflector arrangement is known in the art as an unstable resonator (or unstable resonant cavity), which operates along the long axis of the slab discharge region.

According to one or more embodiments, the laser can be operated in a pulsed mode, particularly for drilling, cutting, etc. The pulse repetition frequency (PRF) and the pulse duty cycle can be selected according to the operation to be performed and according to the material on which the operation is to be performed (for example, the PRF can typically be from less than 1 kilohertz (kHz) to more than 100 kHz). As described above, laser performance (for example, output beam shape, discharge stability, etc.) can be affected at certain frequencies due to acoustic oscillations, which may be caused by, among other reasons, perturbations in the gas discharge volume attributable to changes in the partial pressure of the gas.

FIG1 illustrates an electrode structure using dielectric spacers, which are placed between or otherwise along the edges of the electrodes to contain the discharge and reduce acoustic coupling between the discharge region and structures outside the discharge region. Electrode structure 101 includes a pair of rectangular planar electrodes 103a and 103b (e.g., opposing "hot" and "ground" electrodes) separated by a small lateral gap region 105 (e.g., having a thickness between 1 mm and 5 mm) to define a discharge region 107. Electrodes 103a and 103b can be made of aluminum, although other materials may also be used. Additionally, dielectric spacers 109a and 109b can be positioned within gap region 105 between electrodes 103a and 103b. Dielectric spacers 109a and 109b can also extend parallel to the length of the electrodes, i.e., in the direction into the paper (not shown). The inner edges of spacers 109a and 109b extend all the way to the outer edges of discharge region 107 and can also extend beyond the outer edges of electrodes 103a and 103b. The spacers 109a and 109b may be made of ceramic such as alumina or other non-conductive materials.

In the configuration shown in FIG1 , electrodes 103 a and 103 b and spacers 109 a and 109 b surround a discharge volume such that when the structure is excited by an RF power source (not shown), the excited discharge creates laser light that can resonate within an optical cavity (not shown) and escape only through a final optical surface (creating an output beam generated by the laser radiation escaping from the unstable resonator as output radiation). Laser resonators according to one or more embodiments are described in detail below with reference to FIG4A-4B .

While the configuration shown in FIG. 1 may be beneficial for reducing acoustic oscillations, the outer edges of the discharge interact with the inner edges 110 a and 110 b of the pads 109 a and 109 b , respectively, and create other problems such as beam reflections, laser instabilities, and actual pad burning, thereby reducing the effectiveness and life cycle of the laser.

FIG2A shows a cross-sectional view of a laser tube with baffles according to one or more embodiments of the present invention. The electrode structure 201 includes a pair of rectangular planar electrodes 203a and 203b, each having a concave shelf-shaped outer end portion 213a, 213b, 213c, and 213d, respectively. A pair of baffles 204a and 204b are positioned within the concave shelf-shaped outer end portions 213a, 213b, 213c, and 213d, separating the electrodes 203a and 203b. A cross-section of two parallel elongated electrodes 203a and 203b is shown, separated by a discharge region 205 having a width defined by a gap 207 (e.g., a width of 0.5 mm to 6 mm depending on the RF frequency used).

According to one or more embodiments, baffles 204a and 204b extend along the length (not shown) of electrodes 203a and 203b. Baffles 204a and 204b also include central channels 209a and 209b, respectively, formed on their respective inner surfaces. The central channels extend along the length of baffles 204a and 204b, respectively, and provide separation regions 210a and 210b, respectively. Separation regions 210a and 210b prevent any stray discharges and/or peripheral laser radiation 211 from the discharge region 205 from contacting the inner surfaces 206a and 206b of baffles 204a and 204b, respectively. Furthermore, separation regions 210a and 210b minimize glancing reflections from the baffles of peripheral laser radiation 211 that may extend slightly from the edges of the discharge region 205 and enter separation regions 210a and 210b. Preventing these glancing reflections can prevent the generation of high-order lasing modes within the laser cavity. According to one or more embodiments, the dimensions of channels 209a and 209b can be configured such that little or no discharge (and little or no stray electric field) is observed within channels 209a and 209b and/or separators 210a and 210b. According to one or more embodiments, the transverse vertical dimension of channels 209a and 209b (i.e., width in the y-direction) can be equal to or greater than the width of gap 207 of discharge region 205 to minimize any interaction between the light field and the channels and also to prevent the desired light field within discharge region 205 from being affected by the presence of baffles 204a and 204b. The transverse horizontal dimension (in the x-direction) of the depth of channels 209a and 209b can be a fraction or multiple of the width of gap 207, for example, between 1 mm and 5 mm for a 2.5 mm electrode gap.

According to one or more embodiments, electrodes 203a and 203b can be secured to the baffles using screws, as shown in Figures 3A-3B. The screws can be electrically isolated from the electrodes by non-conductive shoulder washers (not shown). Furthermore, according to one or more embodiments, baffles 204a and 204b can be separated from the sides of electrodes 203a and 203b by non-conductive spacers 225, such that the space 224 between the baffles and the electrodes is less than approximately 0.02 inches. According to one or more embodiments, the spacers can be 0.005-0.050 inches thick. This small gap 224 can prevent discharges from occurring between the electrodes 203a and 203b and the baffles 204a and 204b, while also preventing gases used in the lasing medium from escaping the discharge region 205. According to one or more embodiments, baffles 204a and 204b can be separated on either side by non-conductive spacers 225, as shown in Figure 2A. However, in embodiments utilizing a ground electrode, the gap region between baffles 204a and 204b may not be necessary, and baffles 204a and 204b may directly contact the ground electrode. Furthermore, as shown in FIG2B , according to one or more embodiments, baffles 204a and 204b and electrode 203b may be formed as a single integrated component without departing from the scope of the present disclosure.

FIG3A illustrates a partially exploded perspective view of the electrode structure 201 of FIG2 , according to one or more embodiments of the present invention. Specifically, the elongated rectangular electrodes 203a and 203b are shown with a ceramic sheet 312 to facilitate heat conduction from the electrodes 203a and 203b to the laser housing 350. Furthermore, an exemplary embodiment is shown using a dielectric (e.g., ceramic) disk-shaped spacer 338 (e.g., providing the width of the space 224 in FIG2A ) between the electrodes 203a and 203b and the baffles 204a and 204b. In the embodiment shown in FIG3A , the baffles 204a and 204b are elongated rectangular strips of uniform thickness, each having a central channel 210a and 210b formed on its respective inner surface. The central channels 210a and 210b also extend in the longitudinal (z) direction along the length of the baffles 204a and 204b. In addition, screws 332 are shown securing the electrodes 203a and 203b to the baffles 204a and 204b, including washers 334 and corresponding non-conductive shoulder washers 336 for electrically isolating the baffles 204a and 204b from the electrodes 203a and 203b. Note that the mechanical and electrical connections between the electrodes and baffles shown here may be achieved by other suitable means, such as through bolts, without departing from the scope of the present disclosure.

Additionally, inductors 340 may be spaced along the length of the two electrodes 203a and 203b, connected across the electrodes to ensure uniform voltage excitation along the length of the two electrodes and thereby ensure uniform discharge excitation. The inductors 340 may be connected using, for example, screws 342 and washers 344 to allow electrical contact to the two electrodes. According to one or more embodiments, once assembled, a housing 350 encloses the entire laser system.

FIG3B illustrates another partially exploded perspective view of the electrode structure 201 of FIG2A , according to one or more embodiments of the present invention. More specifically, all elements in FIG3B are identical to those in FIG3A , except for the shapes of the baffles 204a and 204b. Similar to the baffles of FIG3A , these baffles are generally designed as elongated rectangular bars, each having a central channel 210a and 210b formed along the length of its respective inner surface. The baffles of FIG3B differ from those of FIG3A in that they have a plurality of openings 308 , or voids, along their lengths. In other words, the baffles 204a and 204b of FIG3B are formed from two or more rectangular sub-components 205a and 205b connected by an elongated bridge member 206. The embodiment shown in FIG3B is formed from nine rectangular sub-components connected by eight bridge members. However, any number and shape of sub-components and bridge members may be used without departing from the scope of the present disclosure.

According to one or more embodiments, the modified baffle of FIG. 3B provides the acoustic oscillation avoidance benefits of the solid, uniform width baffle of FIG. 3A , while also allowing for modification and/or adjustment of the capacitance between electrodes 203 a and 203 b based on the size and shape of the openings. Since the capacitance C between two electrodes separated by a distance d is given by , where ε _r is the relative permittivity of the material between the plates, ε ₀ is a constant known as the permittivity of a vacuum, and A is the area of overlap between the two plates, adding one or more openings to the baffle can affect the capacitance between the electrodes. In general, by adding one or more openings to a uniform width baffle, a lower capacitance between the electrodes can be achieved relative to a uniform width baffle. Lower capacitance generally results in improved laser pulse performance.

For clarity, the optical components (and other features, such as cooling components) at the end of the laser system are not shown here, and are described in further detail below with reference to Figures 4A-4B. In addition, the size, number, and location of components (e.g., inductors, screws, etc.) are exemplary only and are not meant to limit the scope of the present invention.

FIG4A illustrates an example of a laser using a laser resonator (also referred to herein as a laser cavity), according to one or more embodiments. More specifically, FIG4A illustrates an example of a laser using a laser resonator, such as a slab gas laser 401. However, other types of laser resonators may be utilized without departing from the scope of the present invention. Furthermore, while the examples described herein may illustrate a certain type of resonator design, any resonator design, such as an unstable resonator, may be utilized without departing from the scope of the present invention. As described above in conjunction with FIG3-4 , according to one or more embodiments, the inter-electrode gap 406 is at least partially used to fill the laser gain medium of the discharge region. According to one or more embodiments, the discharge region is defined as the space between the inner surfaces 403a and 405a of the elongated electrodes 403 and 405, respectively. According to one or more embodiments, the inner surfaces 403a and 405a act as two elongated resonator walls that define the discharge region in the lateral direction and, in some embodiments, may also serve as waveguide surfaces for the intra-cavity laser beam in this lateral direction (y-direction). Although the example shown in FIG4A is a slab laser using planar electrodes 403 and 405, any electrode shape is possible without departing from the scope of the present invention. For example, U.S. Patent Application No. 6,603,794, which is incorporated herein by reference in its entirety, discloses a number of different electrode configurations, such as the use of corrugated electrodes, tapered electrodes, and/or ring electrodes.

The slab laser 401 shown in FIG4A also includes an optical resonator formed between an output coupling mirror 411 and a front cavity mirror 407, with a fold mirror 409 for the folded cavity as shown. According to one or more embodiments, a pair of spherical and/or cylindrical mirrors can be used for the front cavity mirror 407 and the fold mirror 409, respectively, and an emission window can typically be used for the output coupling mirror 411. However, other embodiments can use spherical mirrors, cylindrical mirrors, curved mirrors, or generally aspherical mirrors, or any combination thereof, for the resonator without departing from the scope of the present invention. In addition, according to one or more embodiments, the mirrors can be mounted to an end flange (not shown) that maintains vacuum integrity while providing appropriate adjustment of mirror tilt to achieve optimal alignment of the component mirrors of the optical resonator. According to one or more embodiments, the entire slab laser assembly can be placed within a housing, such as the housing 350 shown in FIG3A-3B.

In the example slab laser shown in FIG4A , elongated electrodes 403 and 405 are part of an electrical resonator (which is itself part of a laser resonator), such that the inter-electrode gap defined by resonator surfaces 403a and 405a acts as a discharge region for the gas laser medium. According to one or more embodiments, the tube design shown and described above in conjunction with FIG2-3 may be utilized. According to one or more embodiments, such electrodes may have a length of up to 1 meter, a width of up to 0.5 meters, and an inter-electrode gap on the order of 0.5-6 mm. However, other embodiments may utilize dimensions outside of this range without departing from the scope of the present disclosure. According to one or more embodiments, when radio frequency (often referred to as "RF") power is applied to the gas laser medium via elongated electrodes 403 and 405, a gas discharge forms within inter-electrode gap 406. According to one or more embodiments, laser energy accumulates in one or more modes of the optical resonator, including the fundamental mode, ultimately forming an intra-cavity laser beam (not shown), which travels back and forth between output coupling mirror 411 and front cavity mirror 407 via back folding mirror 409. A small portion of the intracavity laser beam is transmitted through the output coupling mirror 411 and forms an output laser beam 415 .

In the exemplary embodiment shown in FIG4A , the electric resonator cavity, and therefore the gas discharge region, can be rectangular in shape. However, alternative embodiments can utilize square, annular, or other electric resonator cavities. Resonator surfaces 403 a and 405 a can be bare electrode surfaces or electroplated electrode surfaces. Suitable materials for bare embodiments include metals such as aluminum and other metal alloys. Electroplated embodiments can use ceramic materials such as aluminum oxide or beryllium oxide on the electrode surfaces.

As described above, according to one or more embodiments, the inter-electrode gap region (or inner cavity region) can be filled with a gaseous laser medium. For example, the gaseous laser medium can be one part carbon dioxide (CO ₂ ), one part nitrogen (N ₂ ), and three parts helium (He), plus 5% xenon (Xe). The gas pressure can be maintained in the range of approximately 30-150 Torr, for example, 90 Torr. However, other embodiments can use higher gas pressures without departing from the scope of the present invention. Other embodiments of the present invention can use other types of gas lasers, and Table 1 lists other examples.

Other gas mixtures may also be used. For example, some embodiments may use the following gas mixtures or their isotopes, including neon (Ne), carbon monoxide (CO), hydrogen (H ₂ ), water (H ₂ O), krypton (Kr), argon (Ar), fluorine (F), deuterium, or oxygen (O ₂ ), as well as portions of other gases, at various other pressures, such as 30-120 Torr, for example, 50 Torr, examples of which are listed in Table 1 above; however, it will be understood that other gaseous laser media may also be used. For example, an example of a laser medium includes one or more of the following vapors: copper, gold, strontium, barium, copper halides, gold halides, strontium halides, barium halides, and other vapors, as listed in Table 1 above, but not limited to these examples.

Returning to FIG. 4A , according to one or more embodiments, slab laser 401 includes a power supply 417 that supplies excitation energy to a gas laser medium located within gap 406 via first and second elongated electrodes 403 and 405, respectively. Accordingly, the increased excitation energy causes the gas laser medium to emit electromagnetic radiation in the form of a laser beam 415, which ultimately exits the optical resonator via an output coupling window or optical element 411. Included within power supply 417 is a radio frequency generator 417a that generates the excitation energy to be applied to the first and second elongated planar electrodes 403 and 405. According to one or more embodiments, the radio frequency generator can operate at a frequency of 40 MHz and an output power level of at least 3000 W. Other embodiments may utilize other excitation frequencies and power levels without departing from the scope of this disclosure. Furthermore, according to one or more embodiments, the radio frequency generator can be connected to the electrodes in a biphasic manner such that the voltage phase on one of the first and second elongated planar electrodes 403 and 405 is substantially offset by 180 degrees relative to the voltage phase on the other of the first and second elongated planar electrodes 403 and 405. Biphasic excitation can be achieved by any technique known in the art, such as by placing an inductor between first and second electrodes, both of which are isolated from ground. According to one or more alternative embodiments, the RF generator can be connected to one of the first and second elongated planar electrodes such that only one of the first and second elongated planar electrodes is excited and the other electrode is electrically grounded.

The excitation energy supplied by the power supply 417 in the embodiment shown in FIG. 4A may be radio frequency energy, but may also be associated with microwave, pulse, continuous wave, direct current, or any other energy source suitable for exciting the laser medium to generate laser energy.

According to one or more embodiments, the inner surfaces 403a and 405a of the first and second elongated planar electrodes 403 and 405, respectively, are positioned sufficiently close to each other so that the inter-electrode gap serves as a waveguide for the laser radiation along the y-axis. Accordingly, when used as waveguide surfaces, the inner surfaces 403a and 405a can also serve as optical resonator surfaces in the lateral (y-direction). According to one or more embodiments, waveguiding occurs when πN < 1, where N = D ² /(4λL) is the Fresnel number of the waveguide, D is the width of the inter-electrode gap, L is the length of the optical cavity, and λ is the wavelength of the laser radiation. For a wavelength of approximately 10.6 microns (a typical wavelength generated by CO ₂ lasers), the waveguide criterion is met if the inter-electrode gap is less than 2 mm for a waveguide length of 40 cm. However, in other embodiments, the inter-electrode gap is large enough to allow free-space propagation of the laser beam in the y-direction, such as Gaussian beam propagation. Accordingly, in this free-space configuration, these surfaces serve to define the thickness of the gas discharge region rather than serving as waveguides for the laser radiation. Other embodiments may use inter-electrode gap sizes between waveguide standards and pure free-space propagation. According to one or more embodiments, one or more extension members 427, 429 and 431, 433 are positioned near or at the ends 403b, 405b and 403c, 405c of the resonator walls 403 and 405, respectively. Furthermore, in the following embodiments, the surfaces of the resonator walls and/or extension members may or may not constitute waveguide walls and thus may also be used in free-space unstable resonators and hybrid waveguide resonators. The extension members may help avoid damage to the optics and may also reduce power losses.

FIG4B illustrates a simplified top view of an unstable slab laser resonator that can be used as the optical resonator discussed above in conjunction with FIGs. 2-3 and 4A. In slab resonator 401, an intracavity laser beam 404 (depicted by the shaded area in FIG4B) passes multiple times through a laser medium (not shown, but as described above, which can be, for example, _CO₂ gas), thereby forming an optical resonator. As described above in conjunction with FIGs. 2-4A, two elongated baffle members 204a and 204b (also visible in the cross-sections shown in FIGs. 2A-2B) located on longitudinal edge portions of the electrodes are sandwiched between planar electrodes (only the bottom electrode 405 is visible in FIG4B). In accordance with one or more embodiments, the elongated baffle members further include respective elongated central channels 209a and 209b (also visible in the cross-sections of FIGs. 2A-2B), each extending into the inner surface of the respective baffle member to a depth d. Accordingly, as described above in conjunction with Figures 2A-2B , the volume of the elongated central channels 209a and 209b forms a separation zone that separates the discharge region from the inner surface of the baffle member. Also as described above in conjunction with Figures 2A-2B , the elongated planar electrodes are designed such that the discharge region is confined to the central region 433 of the electrode. For example, the central portion of the electrode may be thicker than the longitudinal edge portions, forming a substantially T-shaped cross-section, as shown in Figures 2A-2B . Thus, while the gaseous laser medium may be permitted to migrate into or out of the separation zones formed in the central channels 204a and 204b , no lasing or discharge occurs in these separation zones due to the large gap between the inner electrode surfaces.

The absence of gas discharge in the partition helps protect the inner surface of the baffle member and improves laser mode quality by minimizing glancing reflections of the intracavity laser beam from the inner surface of the baffle member. For example, in the case of an unstable resonator, the intracavity laser beam 404 can fill the entire volume of the optical resonator and can extend slightly outside the optical resonator. Thus, a baffle member without a central channel, and therefore without a partition, allows for many glancing reflections of the intracavity laser beam from the inner surface of the baffle member. Using a central channel having a depth d allows the inner surface of the baffle member to be effectively moved outside the optical resonator and also outside the peripheral region of the optical resonator where peripheral portions of the intracavity laser beam may reside. Thus, depending on the resonator design, the depth d of the extended central channel is selected to be sufficiently long to ensure that the inner surface of the extended baffle member does not interact with (i.e., reflect) the intracavity laser beam. For example, the depth d can range from 1 mm to 20 mm, although depths outside this range can also be used without departing from the scope of the present disclosure.

Embodiments of the invention described herein can thus be used to improve laser performance, such as improving laser beam pointing stability, which is defined as the movement of the beam with the operating frequency of the laser, and can improve beam quality. FIG5 shows a comparison curve showing the beam pointing stability of a laser with a baffle according to one or more embodiments (e.g., FIG2 and 3 ) and without such a baffle (e.g., FIG1 ). The curve clearly shows that the beam movement of the laser utilizing the baffle according to one or more embodiments is significantly reduced (by a factor of approximately 2). Furthermore, minimizing the movement also improves the quality of the laser beam and minimizes any impact of the beam movement on the laser user's application.

Furthermore, the embodiments herein avoid the use of long, thin ceramic shims, similar to shims 109a and 109b shown in FIG1 , which are difficult to manufacture and very easily damaged (increasing the manufacturing cost of such prior art lasers). Furthermore, the design of electrode 110 herein allows for efficient surface polishing due to its generally flat surface (e.g., electrodes 303a and 303b have a generally T-shaped cross-section).

It should be noted that the various non-limiting embodiments described herein can be used individually, in combination, or selectively in combination for specific applications. In addition, some of the various features of the above-mentioned non-limiting embodiments can be used to advantage without corresponding use of other described features. Therefore, the foregoing description should be understood as merely illustrating the principles, teachings, and exemplary embodiments of the present invention, and not as limiting thereof. It should be understood that the above-mentioned arrangement is merely illustrative of the application of the principles of the present invention. For example, the relative dimensions shown herein are illustrative only and can be changed based on the desired laser power level, RF frequency, gas composition, pressure, etc.

While the present invention has been described in conjunction with a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be designed without departing from the scope of the invention disclosed herein. Accordingly, the scope of the present invention should be limited only by the appended claims.

Claims (23)

1. A tube for a slab laser, comprising: Including the first elongated electrode on the inner surface of the first electrode; Including the second elongated electrode on the inner surface of the second electrode, The first elongated electrode is separated from the second elongated electrode in the first transverse direction, thereby defining a gap region with a gap thickness between the inner surfaces of the first electrode and the inner surfaces of the second electrode. The first elongated baffle component and the second elongated baffle component each include an elongated central channel formed on their inner surfaces; The first elongated baffle component and the second elongated baffle component are respectively disposed in the gap region along the first longitudinal edge portion of the first elongated electrode and the second elongated electrode and the second longitudinal edge portion of the first elongated electrode and the second elongated electrode; The first elongated baffle component and the second elongated baffle component are configured such that their inner surfaces face the gap region, such that the inner surfaces of the first elongated electrode, the second elongated electrode, the first elongated baffle component, and the second elongated baffle component cooperate to surround the gap region; The elongated central channel of the first elongated baffle component and the second elongated baffle component is used to extend the gap area to the depth of the elongated central channel in the second lateral direction, thereby defining a separation area extending in the elongated central channel along the length of the first elongated baffle component and the second elongated baffle component respectively in the longitudinal direction; The inner surfaces of the first elongated baffle component and the second elongated baffle component cooperate to reduce the acoustic oscillation of the gas laser medium disposed in the gap region; The first and second elongated baffle components each include a plurality of rectangular components interconnected by a plurality of bridge-like components, wherein the thickness of the plurality of rectangular components in the first lateral direction is greater than the thickness of the bridge-like components in the first lateral direction, and wherein the bridge-like components are located at the center of the first and second elongated baffle components in the first lateral direction; and The elongated central channel of the first elongated baffle component and the second elongated baffle component extends along the length of the inner surface of the bridge component, and the inner surface of the elongated central channel cooperates to reduce the acoustic oscillation of the gas laser medium disposed in the gap region. 2. The tube according to claim 1 further includes a discharge region disposed within the central portion of the gap region, wherein the partition regions are respectively disposed between the outer edge of the discharge region and the inner surface of the first elongated baffle member and between the outer edge of the discharge region and the inner surface of the second elongated baffle member, and the partition regions do not support gas discharge. 3. The tube according to claim 1, wherein the partition regions are respectively disposed between the peripheral portion of the inner cavity laser beam and the inner surface of the first elongated baffle member and between the peripheral portion of the inner cavity laser beam and the inner surface of the second elongated baffle member, thereby avoiding grazing reflection of laser radiation from the inner surfaces of the first elongated baffle member and the second elongated baffle member. 4. The tube according to claim 2, wherein the thickness of the first elongated electrode in the discharge region is greater than the thickness along the first longitudinal edge and the second longitudinal edge. 5. The tube according to claim 4, wherein the thickness of the gap region in the discharge region is less than the thickness of the gap along the first longitudinal edge and the second longitudinal edge. 6. The tube according to claim 5, wherein the first longitudinal edge portion and the second longitudinal edge portion of the first elongated electrode are concave frame-like surfaces. 7. The tube of claim 6, wherein the concave frame-like surface is adapted to receive the first elongation baffle component and the second elongation baffle component disposed between the first elongation electrode and the second elongation electrode. 8. The tube according to claim 1, wherein the first elongated baffle component includes an opening disposed along its length in the longitudinal direction. 9. The tube according to claim 1, wherein the first elongated baffle component includes a plurality of openings disposed along its length in the longitudinal direction. 10. The tube according to claim 1, wherein the first elongation baffle component and the second elongation baffle component are made of a conductive material. 11. The tube according to claim 1, wherein the first elongation baffle component and the second elongation baffle component are made of aluminum. 12. The tube according to claim 1, wherein the first elongation baffle component and the second elongation baffle component are made of ceramic. 13. The tube according to claim 11, wherein the first elongation baffle component and the second elongation baffle component are spaced apart from the first elongation electrode and the second elongation electrode by means of a ceramic gasket. 14. The tube according to claim 1, wherein the first elongation baffle component and the second elongation baffle component are integrated portions of the first elongation electrode. 15. The tube according to claim 1, wherein the first elongation baffle component and the second elongation baffle component are made of insulating material. 16. A tube for a slab laser, comprising: Including the first elongated electrode on the inner surface of the first electrode; Including the second elongated electrode on the inner surface of the second electrode, The first elongated electrode is separated from the second elongated electrode in the first transverse direction, thereby defining a gap region with a gap thickness between the inner surfaces of the first electrode and the inner surfaces of the second electrode. The first elongated baffle component and the second elongated baffle component each include an elongated central channel formed on their inner surfaces; The first elongated baffle component and the second elongated baffle component are respectively disposed in the gap region along the first longitudinal edge portion of the first elongated electrode and the second elongated electrode and the second longitudinal edge portion of the first elongated electrode and the second elongated electrode; The first elongated baffle component and the second elongated baffle component are configured such that their inner surfaces face the gap region, such that the inner surfaces of the first elongated electrode, the second elongated electrode, the first elongated baffle component, and the second elongated baffle component cooperate to surround the gap region; The first elongated baffle component and the second elongated baffle component each include an opening portion disposed along their length in the longitudinal direction. The inner surfaces of the first elongated baffle component and the second elongated baffle component cooperate to reduce the acoustic oscillation of the gas laser medium disposed in the gap region; The first and second elongated baffle components each include a plurality of rectangular components interconnected by a plurality of bridge-like components, wherein the thickness of the plurality of rectangular components in the first lateral direction is greater than the thickness of the bridge-like components in the first lateral direction, and wherein the bridge-like components are located at the center of the first and second elongated baffle components in the first lateral direction; and The elongated central channel of the first and second elongated baffle components extends along the length of the inner surface of the bridge component, and The inner surface of the elongated central channel cooperates to reduce acoustic oscillations of the gas laser medium disposed in the gap region. 17. The pipe of claim 16, wherein the elongated central channel of the first elongated baffle member and the second elongated baffle member is used to extend the gap region to the depth of the elongated central channel in a second transverse direction, thereby defining a partition region extending in the elongated central channel along the length of the first elongated baffle member and the second elongated baffle member respectively in the longitudinal direction. 18. The tube of claim 17, wherein the first elongated baffle component includes a plurality of openings disposed along its length in the longitudinal direction. 19. The tube of claim 16, wherein the thickness of the gap region adjacent to the central portion is less than the thickness of the gap region along the first longitudinal edge and the second longitudinal edge. 20. The tube according to claim 17, wherein the first longitudinal edge portion and the second longitudinal edge portion of the first elongated electrode are concave frame-like surfaces. 21. The tube of claim 20, wherein the concave frame-like surface is adapted to receive the first elongation baffle component and the second elongation baffle component disposed between the first elongation electrode and the second elongation electrode. 22. The tube of claim 16, wherein the first elongation baffle component and the second elongation baffle component are made of insulating material. 23. The tube of claim 16, wherein the first elongation baffle component and the second elongation baffle component are made of a conductive material.