KR20160145277A - Optical signal coupling appratus and method using grating-to-grating coupler having bandwidth performance enhancement - Google Patents

Abstract

An optical signal coupling apparatus is disclosed. An embodiment of the present invention includes an input optical element which includes a first coupler and a first reflector for reflecting a part of an optical signal separated by the first coupler, and an output optical element which has a second coupler which is positioned corresponding to the first coupler and a second reflector reflecting a part of the optical signal separated by the second coupler, outputs an output optical signal having a resonant frequency by using an optical signal that is reciprocated between the first coupler and the second coupler based on the reflection of the first reflector and the reflection of the second reflector. So, the coupling efficiency of the optical signal can be improved.

Description

[0001] The present invention relates to an optical signal coupling device and a method of coupling optical signals using a grating-to-grating coupler having improved frequency bandwidth, and a method of coupling optical signals using the grating coupler,

The following embodiments relate to an optical signal coupling device and a method of optical signal coupling using a grating-to-grating coupler.

In order to overcome the limitation of metal waveguide bandwidth, researches on optical interconnect have been actively carried out. In particular, silicon-based optical interconnects have received much attention. In order to realize silicon-based optical interconnects, optical signals should be transmitted at very small distances in micro or millimeter intervals. Various coupler structures enable optical signal coupling, but it is difficult to achieve high coupling efficiency and wide frequency bandwidth.

An optical signal coupling device according to one side includes an input optical device including a first coupler and a first reflector that reflects a part of the optical signal separated by the first coupler; And a second coupler positioned corresponding to the first coupler and a second reflector reflecting a part of the optical signal separated by the second coupler, wherein the reflection of the first reflector and the reflection of the second reflector And an output optical element for outputting an output optical signal having a resonant frequency using an optical signal that is reciprocated between the first coupler and the second coupler as a basis.

The resonant frequency of the output optical signal may be determined based on a distance between the first coupler and the second coupler.

The first coupler may separate the input optical signal input to the input optical element into an optical signal directed to the second coupler and an optical signal directed to the first reflector.

In addition, a resonance cavity may be formed in the optical signal coupling device based on the first reflector and the second reflector.

The second coupler may separate the optical signal reflected by the second reflector into an optical signal directed to the first coupler and an optical signal directed to a waveguide of the output optical element.

The first coupler and the second coupler may be a grating coupler.

In addition, the first coupler and the second coupler may be vertically opposed to each other.

Further, each of the first reflector and the second reflector may be inserted into the cladding of the input optical element and the cladding of the output optical element.

A method of coupling an optical signal according to an exemplary embodiment includes: reflecting a part of an optical signal separated by a first coupler using a first reflector; Reflecting a part of the optical signals separated by the second coupler corresponding to the first coupler using a second reflector; And outputting an output optical signal having a resonant frequency using an optical signal that is based on the reflection of the first reflector and the reflection of the second reflector.

The resonant frequency of the output optical signal may be determined based on a distance between the first coupler and the second coupler.

The first coupler may separate an input optical signal input to the first coupler into an optical signal directed to the second coupler and an optical signal directed to the first reflector.

A resonance cavity may be formed based on the first reflector and the second reflector.

The second coupler may separate an optical signal reflected by the second reflector into an optical signal directed to the first coupler and an optical signal directed to a waveguide of the output optical element.

The first coupler and the second coupler may be a grating coupler.

The first coupler and the second coupler may be located vertically opposite to each other.

According to one embodiment, the coupling efficiency of optical signals in optical interconnects can be increased and a wide frequency bandwidth of the optical signal can be secured. It is possible to implement a silicon 3D optical integrated circuit and an LSI (Large-Scale Integration) chip with increased efficiency and performance.

FIG. 1 is a view for explaining optical signal coupling of a carrier chip separated from each other by using a bridge chip.
2 is a view for explaining optical signal coupling between waveguides separated from each other in an inter-layer.
FIG. 3 is a view for explaining the direction of light according to diffraction orders satisfying Bragg Condition. FIG.
4 is a view for explaining a Bragg reflector.
5 is a view illustrating a structure of a fiber-to-grating coupler and a grating-to-grating coupler.
6 is a view for explaining resonance of an optical signal between a grating coupler and a grating coupler.
7 is a view for explaining an optical signal combining apparatus according to an embodiment.
8 is a view for explaining a frequency bandwidth and a coupling efficiency by optical signal coupling according to an embodiment.
9 is a flowchart illustrating an optical signal combining method according to an embodiment.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

Various modifications may be made to the embodiments described below. It is to be understood that the embodiments described below are not intended to limit the embodiments, but include all modifications, equivalents, and alternatives to them.

The terms used in the examples are used only to illustrate specific embodiments and are not intended to limit the embodiments. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having" and the like refer to the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this embodiment belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as ideal or overly formal in the sense of the art unless explicitly defined herein Do not.

In the following description of the present invention with reference to the accompanying drawings, the same components are denoted by the same reference numerals regardless of the reference numerals, and redundant explanations thereof will be omitted. In the following description of the embodiments, a detailed description of related arts will be omitted if it is determined that the gist of the embodiments may be unnecessarily blurred.

FIG. 1 is a view for explaining optical signal coupling of a carrier chip separated from each other by using a bridge chip.

Referring to FIG. 1, an optical signal may be transmitted from the carrier chip 110 to the carrier chip 130 through the bridge chip 120. In the structure in which the layers are separated from each other, the transmission of the optical signal can be performed through the bridge chip 120. The layer to which the carrier chip 110 belongs and the layer to which the carrier chip 130 belongs may be separated from each other. The optical signal inputted to the carrier chip 110 can be transmitted to the coupler of the bridge chip 120 by the coupler of the carrier chip 110 and can be transmitted to the coupler of the carrier chip 130 by the coupler of the bridge chip 120 Lt; / RTI >

2 is a view for explaining optical signal coupling between waveguides separated from each other in an inter-layer.

Referring to FIG. 2, different waveguides are separated in one layer. Between the waveguide 210 and the waveguide 220, a material of the layer can be filled. The optical signal coupling using the bridge chip shown in FIG. 1 and the optical signal coupling between the waveguide inside the layer shown in FIG. 2 can be used when coupling optical signals between optical waveguides separated from each other and parallel .

FIG. 3 is a view for explaining the direction of light according to diffraction orders satisfying Bragg Condition. FIG.

A grating coupler uses a grating with a periodic refractive index as a coupler. A grating coupler combines an optical signal using a diffraction phenomenon of light from an optical waveguide to another optical waveguide. A uniform grating coupler can be obtained by periodically etching the silicon optical waveguide. Thus, a periodic effective refractive index can be exhibited in a uniform grating coupler. When an optical signal meets a periodic structure, a diffraction phenomenon, which is one of the characteristics of an electromagnetic wave, may occur. When an optical signal traveling along the optical waveguide enters the grating coupler, the optical signal travels in a direction different from the traveling direction before entering the gray-tapped coupler. More specifically, when the Bragg condition is satisfied, the light incident on the grating coupler can travel in the other direction. The Bragg condition is expressed by Equation (1).

[Equation 1]

는 그레이팅 커플러의 유효 굴절률,

는 회절에 의해 광 신호가 진행하는 방향의 물질의 굴절률,

는 수직면을 기준으로 광 신호가 회절되는 각도, m은 정수,

는 그레이팅 커플러에 입사하는 광 신호의 파장, 및

는 그레이팅의 주기를 나타낸다.In Equation (1)

The effective refractive index of the grating coupler,

The refractive index of the material in the direction in which the optical signal propagates due to the diffraction,

Is an angle at which the optical signal is diffracted with respect to the vertical plane, m is an integer,

The wavelength of the optical signal incident on the grating coupler, and

Represents the period of the grating.

와 m(차수)에 따른 K 값이 결정될 수 있다.Referring to FIG. 3, when an optical signal having a constant wavelength is incident on the grating coupler,

And the K value according to m (degree) can be determined.

m is 1, the duty ratio is 0.5, the grating period that affects the effective refractive index is 680 nm, and the etch thickness is 100 nm (the grating period and etching thickness are time domain finite element Optimum values based on the analysis method), the optical signal incident on the grating coupler is split in two directions. Here, the duty ratio can represent the width of the lattice / the period of the lattice. One of the separated optical signals is in the upward direction and the other is in the downward direction toward the substrate. Theoretically, the amount of the optical signal traveling in the upward and downward directions of the grating coupler is the same due to the diffraction characteristic caused by the periodic difference of the effective refractive index. The amount of optical signal traveling in the upward and downward directions is slightly different due to the edge scattering generated at the edge of the grating by the etching and the refractive index of the material above and below the grating coupler. An optical signal traveling in a downward direction may be a major cause of optical loss.

4 is a view for explaining a Bragg reflector.

A Bragg reflector is a reflector that periodically arranges materials with different refractive indices and uses periodic reflection interference and destructive interference. The reflectivity of the Bragg reflector may be higher than that of other reflectors. One type of Bragg reflector is the DBR (Distribute Bragg Reflector).

The main material used to make DBRs is GaAs-AlAs. In DBR using GaAs-AlAs with a relatively low refractive index difference, the stopband of the frequency spectrum is wide, but about 10 periodic layers of GaAs-AlAs are required to obtain a high reflectance. On the other hand, DBR using Si-SiO ₂ with a relatively high refractive index difference does not have a wide stopband of the frequency spectrum, but a reflectance of 90% or more can be obtained by using two periodic silicon layers.

Referring to FIG. 4, the structure of a Bragg reflector used as Si and SiO 2 under a grating coupler is shown. The Si layer and the Si layer of the Bragg reflector are separated by a certain distance (420). Of the optical signals separated by the grating coupler, the optical signal to the substrate is reflected by the Bragg reflector and proceeds to the grating coupler. The phase of the optical signal separated by the grating coupler must be in phase with each other so that the optical signal traveling in the other direction and the optical signal reflected by the Bragg reflector are coupled by the grating coupler to become constructive interference. The distance (410) between the grating coupler and the Bragg reflector should be appropriate for proper phase alignment.

5 is a view illustrating a structure of a fiber-to-grating coupler and a grating-to-grating coupler.

Referring to FIG. 5 (a), a fiber-to-grating coupler is shown and a grating-to-grating coupler is shown in FIG. 5 (b). There are structural differences between fiber-to-grating couplers and grating-to-grating couplers. As shown in FIG. 5, the fiber-to-grating coupler includes one grating coupler, and the grating-to-grating coupler includes two grating couplers.

In the case of a fiber-to-grating coupler, the optical signal from the fiber 510 is coupled to the silicon optical waveguide through the grating coupler of the optical device 520.

In the case of the grating-to-grating coupler, the silicon optical waveguide of the optical element 530 and the silicon optical waveguide of the optical element 540 are separated in parallel, and the optical signal is coupled through the grating coupler located in each optical waveguide . The optical signal incident on the silicon optical waveguide of the optical element 530 proceeds perpendicularly to the traveling direction by the grating coupler, enters the grating coupler of the optical element 540, and travels in the same direction as the initial traveling direction.

Also, fiber-to-grating couplers and grating-to-grating couplers differ in mode mismatch. In the case of a fiber-to-grating coupler, the optical signal propagates in a rectangular waveguide and a circular waveguide, so that the influence of a mode mismatch can be large, thereby causing a large optical loss. More specifically, the optical signal output from the fiber follows the Gaussian beam with the maximum intensity at the center of the core, and the optical signal output from the grating coupler is not an Gaussian beam but an exponential It follows the shape of one form of beam. Accordingly, in the case of the fiber-to-grating coupler, a mode mismatch is large. In the case of a grating-to-grating coupler, the optical signal propagated through the rectangular waveguide passes through the grating coupler again to the rectangular waveguide, so that the optical loss is small due to a relatively small influence of the mode mismatch over the fiber-to-grating coupler.

6 is a view for explaining resonance of an optical signal between a grating coupler and a grating coupler.

Optical signals in the Fabry-Perot cavity are reciprocated by the refractive index difference of the mirrors or other materials at both ends, and optical signals that are reciprocating are canceled or canceled by destructive or constructive interference A resonance phenomenon occurs. The reciprocation of the optical signal between the parallel waveguides is similar to the optical signal in the Fabry-Perot cavity.

The optical signal incident on the waveguide 612 of the optical element 610 is incident on the grating coupler, and the optical signal incident on the grating coupler is separated in the upward and downward directions by the Bragg condition. The light traveling in the downward direction is guided back to the grating coupler by the Bragg reflector 611. The optical signal reflected by the Bragg reflector 611 and the optical signal traveling in the upward direction by the Bragg condition are incident on the grating coupler located in the waveguide 622 of the physically separated optical element 620. [ Of the optical signals incident on the grating coupler located in the waveguide 622, a small amount of optical signals are reflected, and the remaining optical signals are separated by a grating coupler located in the waveguide 622. More specifically, the optical signal traveling to the waveguide 622 and the optical signal traveling to the substrate of the optical element 620 are separated by the Bragg condition. The optical signal traveling to the substrate of optical element 620 is reflected by Bragg reflector 621 and proceeds to a grating coupler located in waveguide 622. Here, the optical signal reflected by the Bragg reflector 621 is separated into an optical signal that couples to the waveguide 622 and an optical signal that does not combine with the waveguide 622 but proceeds to the grating coupler located in the waveguide 612. The optical signal is reciprocated between the grating coupler of the waveguide 612 and the grating coupler of the waveguide 622, and the optical signal is reciprocated to generate resonance. The resonance occurrence condition is expressed by Equation (2).

&Quot; (2) "

는 초기에 그레이팅 커플러에 입사하는 광 신호의 파장을 나타낸다.

를 갖는 광 신호는 수학식 2에 의해 획득된 d를 갖는 구조에서 공진할 수 있다. 수학식 2에서, d는 grating-to-grating coupler의 성능을 결정짓는 중요한 요소가 될 수 있다. d가 조정됨으로써

를 갖는 광 신호의 공진 현상이 발생할 수 있다.
d is the distance between the grating coupler located at the waveguide 612 and the grating coupler located at the waveguide 622 and d ₀ is the equivalent distance to the phase change occurring at the grating interface the grating interface. Further, m is a positive integer, and the resonance by m can be maximized according to the periodic distance. Also,

Represents the wavelength of the optical signal initially incident on the grating coupler.

Can resonate in a structure having d obtained by Equation (2). In Equation (2), d may be an important factor determining the performance of the grating-to-grating coupler. d is adjusted

The resonance phenomenon of the optical signal having the wavelength?

7 is a diagram for explaining optical signal combining according to an embodiment.

Referring to FIG. 7, an input optical element 710 and an output optical element 720 are shown.

A Bragg reflector is inserted into the cladding 712 and 722 of the input optical element 710 and the output optical element 720, respectively, to couple the optical signal. In the case of waveguides 711 and / or 721, it may be a single mode optical waveguide and may be 220 nm thick. A cladding (712 and / or 722) may be a thickness of 2μm, it can be composed of SiO ₂ (silica). The grating coupler may be a grating coupler that is in the basic TE mode (2.83) because it is highly affected by the polarization state.

An input optical signal is input to the waveguide 711, and the input optical signal traveling through the waveguide 711 is separated by a grating coupler. The grating coupler can separate the input optical signal into an optical signal traveling to the output optical element 720 and an optical signal traveling to the substrate 713. The optical signal traveling to the substrate 710 is reflected by the Bragg reflector inserted in the cladding 712 and proceeds to a grating coupler located in the waveguide 711.

The grating coupler located in the waveguide 711 can couple the optical signal reflected by the Bragg reflector and the optical signal traveling to the output optical element 720. Constructive interference may occur during coupling. The optical signal reflected by the Bragg reflector and the optical signal traveling to the output optical element 720 may be incident on the grating coupler located in the waveguide 721 of the output optical element 720. The grating coupler located in the waveguide 721 can separate the incident optical signal into an optical signal traveling to the substrate 723 of the output optical element 720 and an optical signal coupling with the waveguide 721.

The optical signal traveling to the substrate 723 is reflected by the Bragg reflector inside the cladding 722 and proceeds to a grating coupler located in waveguide 721. The grating coupler located in the waveguide 711 and the grating coupler located in the waveguide 721 may be positioned to correspond to each other. For example, the grating coupler located in the waveguide 711 and the grating coupler located in the waveguide 721 may be positioned parallel to each other. Also, the grating coupler located in waveguide 721 can be laterally shifted.

The grating coupler located in the waveguide 721 can separate the reflected optical signal into an optical signal coupling the waveguide 721 and an optical signal traveling to the input optical element 710. An optical signal traveling to the input optical element 710 may be incident on a grating coupler located in the waveguide 711. The optical signal incident on the grating coupler located in the waveguide 711 may be separated and some of the separated optical signals may be reflected by the Bragg reflector.

The optical signal can be reciprocated between the input optical element 710 and the output optical element 720 by separation and reflection of the optical signal. That is, the optical signal can be reciprocated between the grating coupler located at the waveguide 711 and the grating coupler located at the waveguide 721 by separation and reflection of the optical signal. Resonance can be caused by reciprocation of the optical signal, and an output optical signal having a resonance frequency can be generated. Here, the resonant frequency can be determined by the distance between the input optical element 710 and the output optical element 720, that is, the distance between the grating coupler located at the waveguide 711 and the grating coupler located at the waveguide 721.

The output optical element 720 outputs an output optical signal having a resonant frequency. In the frequency characteristics of the output optical signal, the frequency bandwidth due to the characteristic of the grating coupler and the resonance frequency due to the generated resonance overlap each other. The frequency bandwidth of the output optical signal can be obtained by at least one of the grating coupler located in the waveguide 711 and the grating coupler located in the waveguide 721 and the resonant frequency can be overlapped in the obtained frequency bandwidth. For this reason, the output optical signal may not have a single resonant frequency, and may have a wide bandwidth by overlapping.

8 is a view for explaining a frequency bandwidth and a coupling efficiency by optical signal coupling according to an embodiment.

Referring to FIG. 8, the coupling efficiency and the frequency bandwidth of the output optical signal can be confirmed when the Bragg reflector is used (810) and when the Bragg reflector is not used (820). Here, the coupling efficiency can be determined based on the intensity of the output optical signal with respect to the intensity of the input optical signal.

If a Bragg reflector is used (810), a relatively wide frequency bandwidth can be obtained based on the resonant frequency. Also, high coupling efficiency at the resonant frequency appears. On the other hand, if the Bragg reflector is not used (820), the bandwidth of the output optical signal is relatively narrow and the coupling efficiency is also relatively low. The coupling efficiency and the frequency bandwidth of the output optical signal can be maximized using resonance enhancement.

9 is a flowchart illustrating an optical signal coupling method according to an embodiment.

An optical signal coupling method according to an embodiment can be performed by an optical signal coupling device. Referring to FIG. 9, the optical signal coupling apparatus reflects a part of the optical signals separated by the first coupler using a first reflector (910). The optical signal coupling device can separate the input optical signal traveling along the waveguide using a first coupler. At this time, the first coupler can separate the input optical signal into an optical signal directed to the second coupler and an optical signal directed to the first reflector. The first reflector may be positioned corresponding to the first coupler. For example, the first reflector may be positioned parallel to the first coupler.

The optical signal coupling device reflects (920) some of the optical signals separated by the second coupler located corresponding to the first coupler using the second reflector. The second coupler may be positioned parallel to the first coupler. That is, the first coupler and the second coupler can be positioned facing each other. Here, the second coupler can be laterally shifted. The optical signal reflected by the first reflector and the optical signal traveling to the second coupler are incident on the second coupler. The second coupler separates the incident optical signal. More specifically, the second coupler may be separated into an optical signal coupled to the waveguide in which the second coupler is located and an optical signal propagating to the second reflector. Here, the optical signal traveling to the second reflector may be reflected back to the second coupler. The second reflector may be positioned corresponding to the second coupler. For example, the second reflector may be positioned parallel to the second coupler. The second coupler can separate the reflected optical signal into an optical signal coupling the optical waveguide with the waveguide and an optical signal directed to the first coupler.

The optical signal coupling device can reciprocate the optical signal between the first coupler and the second coupler through the optical signal separation of the first coupler and the second coupler and the optical signal reflection of the first reflector and the second reflector. Resonance can be caused by reciprocation of the optical signal, and an output optical signal having a resonance frequency can be generated. Here, the resonant frequency of the output optical signal can be determined based on the distance between the first coupler and the second coupler.

The optical signal coupling apparatus according to an exemplary embodiment of the present invention can minimize the loss of the optical signal traveling to the substrate and further inject optical signals between the grating couplers. As a result, the resonance frequency due to the resonance phenomenon due to the reciprocation of the optical signal between the grating coupler and the grating coupler is overlapped, and the coupling efficiency and frequency bandwidth of the output optical signal can be improved by overlapping.

Optical interconnects can be used to handle the ever-increasing data rates. To realize optical interconnects, it is important to secure low bandwidth and low loss of optical signals. In the optical integrated circuit, if the low loss and bandwidth of the optical signal are secured, it is possible to manufacture a data center for processing large data and a supercomputer having high performance.

Although optical coupler coupling can be realized through various couplers, miniaturization and easy chip placement are not easy for high coupling efficiency and bandwidth. Further, optical signal coupling of vertically separated optical waveguides is not easy. Density optical integrated circuit for optical signal coupling of vertically separated optical waveguides, which can be easily miniaturized, as well as being easily arranged on a chip via a grating coupler.

In the case of a grating coupler, coupling efficiency and frequency bandwidth are low because of the use of diffraction phenomenon. According to one embodiment, a Bragg reflector is added at the bottom of the grating coupler for high coupling efficiency and frequency bandwidth. Also, according to one embodiment, a resonance phenomenon occurs due to repeated optical signal reciprocation between optical waveguides, and a frequency bandwidth wider than the existing frequency bandwidth can be ensured.

According to one embodiment, a grating coupler produced by etching a silicon-based optical waveguide through a CMOS process is used, a grating-to-grating coupler is formed by further using a grating coupler, and a grating-to- Coupling of the optical signal between the optical waveguides is possible. In addition, the addition of a Bragg reflector under the grating coupler increases coupling efficiency and frequency bandwidth compared to conventional grating couplers.

The apparatus described above may be implemented as a hardware component, a software component, and / or a combination of hardware components and software components. For example, the apparatus and components described in the embodiments may be implemented within a computer system, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA) , A programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For ease of understanding, the processing apparatus may be described as being used singly, but those skilled in the art will recognize that the processing apparatus may have a plurality of processing elements and / As shown in FIG. For example, the processing unit may comprise a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as a parallel processor.

The software may include a computer program, code, instructions, or a combination of one or more of the foregoing, and may be configured to configure the processing device to operate as desired or to process it collectively or collectively Device can be commanded. The software and / or data may be in the form of any type of machine, component, physical device, virtual equipment, computer storage media, or device , Or may be permanently or temporarily embodied in a transmitted signal wave. The software may be distributed over a networked computer system and stored or executed in a distributed manner. The software and data may be stored on one or more computer readable recording media.

The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents, even if it is replaced or replaced.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (17)

An input optical element including a first coupler and a first reflector that reflects a part of the optical signal separated by the first coupler; And
A second coupler positioned corresponding to the first coupler, and a second reflector reflecting a part of the optical signal separated by the second coupler, wherein the reflection of the first reflector and the reflection of the second reflector are based on An output optical element for outputting an output optical signal having a resonant frequency using an optical signal that is reciprocated between the first coupler and the second coupler,
/ RTI >
Optical signal coupling device.
The method according to claim 1,
Wherein the resonant frequency of the output optical signal,
And a second coupler coupled to the second coupler,
Optical signal coupling device.
The method according to claim 1,
The output optical signal includes:
Wherein the frequency bandwidth obtained based on at least one of the first coupler and the second coupler overlaps with the resonant frequency,
Optical signal coupling device.
The method according to claim 1,
Wherein the first coupler includes:
An input optical signal input to the input optical element is divided into an optical signal directed to the second coupler and an optical signal directed to the first reflector.
Optical signal coupling device.
The method according to claim 1,
Wherein a resonance cavity is formed in the optical signal coupling device based on the first reflector and the second reflector,
Optical signal coupling device.
The method according to claim 1,
Wherein the second coupler comprises:
And separating the optical signal reflected by the second reflector into an optical signal directed to the first coupler and an optical signal directed to a waveguide of the output optical element,
Optical signal coupling device.
The method according to claim 1,
Wherein the first coupler and the second coupler,
A grating coupler,
Optical signal coupling device.
The method according to claim 1,
Wherein the first coupler and the second coupler,
Which are vertically opposed to each other,
Optical signal coupling device.
The method according to claim 1,
Wherein each of the first reflector and the second reflector includes:
A cladding of the input optical element and a cladding of the output optical element,
Optical signal coupling device.
Reflecting a part of the optical signals separated by the first coupler using a first reflector;
Reflecting a part of the optical signals separated by the second coupler corresponding to the first coupler using a second reflector; And
Outputting an output optical signal having a resonant frequency using an optical signal that is based on the reflection of the first reflector and the reflection of the second reflector;
/ RTI >
Optical signal coupling method.
11. The method of claim 10,
Wherein the resonant frequency of the output optical signal,
And a second coupler coupled to the second coupler,
Optical signal coupling method.
11. The method of claim 10,
The output optical signal includes:
Wherein the frequency bandwidth obtained based on at least one of the first coupler and the second coupler overlaps with the resonant frequency,
Optical signal coupling method.
11. The method of claim 10,
Wherein the first coupler includes:
And a second coupler for separating the input optical signal input to the first coupler into an optical signal directed to the second coupler and an optical signal directed to the first reflector.
Optical signal coupling method.
11. The method of claim 10,
Wherein a resonance cavity is formed based on the first reflector and the second reflector,
Optical signal coupling method.
11. The method of claim 10,
Wherein the second coupler comprises:
And separating the optical signal reflected by the second reflector into an optical signal directed to the first coupler and an optical signal directed to a waveguide of the output optical element,
Optical signal coupling method.
11. The method of claim 10,
Wherein the first coupler and the second coupler,
A grating coupler,
Optical signal coupling method.
11. The method of claim 10,
Wherein the first coupler and the second coupler,
Which are vertically opposed to each other,
Optical signal coupling method.

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