RU76723U1 - TELESCOPIC EXPANDER OF LASER BEAM - Google Patents

Abstract

The utility model relates to optical instrumentation, namely, to laser beam expanders, which can be used without refocusing laser beams for wavelengths of 1.06 μm and 0.63 μm. The objective of the utility model is to increase the multiplicity of the system, to increase the removal of the exit pupil while maintaining the diffraction quality of the image for wavelengths of 1.06 μm and 0.63 μm. The telescopic laser beam expander consists of an optically coupled lens and an eyepiece, the lens containing a biconvex lens, a biconcave lens and a positive lens, and the eyepiece is made in the form of a biconcave lens, unlike the prototype, the biconcave and biconvex lenses of the objective are separated by an air gap, the positive lens made in the form of a meniscus facing a concave surface to the eyepiece. 2 Fig.

Description

The utility model relates to optical instrumentation, namely, to laser beam expanders, which can be used without refocusing laser beams for wavelengths of 1.06 μm and 0.63 μm.

Known telescopic laser beam expander, consisting of four components [1], the first of which is a negative meniscus facing a concave surface to the radiation space of laser beams, the second component is made in the form of a biconvex lens, the third component is made in the form of a positive meniscus facing a convex surface to the space of laser radiation, the fourth component is made in the form of a biconvex lens. The first component is the negative eyepiece, the second, third and fourth components make up the positive lens. This design provides a 5-fold expansion of the laser beam with a diameter of up to 2 mm with diffraction quality in the spectral range from 0.365 μm to 1.3 μm. The disadvantage of this design is that it does not provide removal of the entrance pupil of more than 40 mm with an entrance pupil diameter of more than 2 mm and an expansion of the laser beam more than 5 times.

Closest to the proposed system is a telescopic optical system [2], consisting of a lens and an eyepiece. The lens consists of two positive lenses, the first of which is a double-glued lens, consisting of a biconvex and biconcave

lenses, and the second lens is made in the form of a single plano-convex lens, facing a flat surface to the eyepiece. The eyepiece consists of a single negative lens made biconcave. This design provides a 5.5x magnification with high image quality and a short system length not exceeding 46 mm. Removal of the exit pupil is 7 mm. However, the disadvantage of the prototype is that when converted to an increase of 7 times, this system does not provide the necessary image quality.

The objective of the utility model is to increase the multiplicity of the system, to increase the removal of the exit pupil while maintaining the diffraction quality of the image for wavelengths of 1.06 μm and 0.63 μm.

The telescopic laser beam expander consists of an optically coupled lens and an eyepiece, the lens containing a biconvex lens, a biconcave lens and a positive lens, and the eyepiece is made in the form of a biconcave lens, unlike the prototype, the biconcave and biconvex lenses of the objective are separated by an air gap, the positive lens made in the form of a meniscus facing a concave surface to the eyepiece.

The arrangement of the biconvex and biconcave lenses of the lens with an air gap between them, the implementation of a positive meniscus lens in the form of a meniscus facing the concave surface to the eyepiece, provided an increase in the system up to 7 times, removal of the exit pupil with a diameter of 3.6 mm of at least 40 mm while maintaining a high degree of correction of spherical aberration and coma.

Figure 1 shows the optical diagram of a telescopic laser beam expander.

Figure 2 shows the design parameters of the telescopic laser beam expander.

The laser beam expander consists of four components. The first component is made in the form of a biconvex lens 1. The second component is a biconcave lens 2. The first and second components are separated by an air gap of 0.5 mm. The third component is made in the form of a positive meniscus 3, facing a concave surface to the eyepiece. Lenses 1-3 form a lens. The focal length of the lens is 60 mm. The fourth component is a biconcave lens 4, acting as an eyepiece. The focal length of the eyepiece is - 8.45 mm.

The optical system operates as follows. Laser radiation from a laser source, combined with the exit pupil of the system, located at a distance of at least 40 mm from lens 4, falls on the negative lens 4, which acts as an eyepiece, after which it expands and falls on the lens 3, 2, 1 of the lens. The rear focus of the lens coincides with the front focus of the eyepiece and therefore a parallel laser beam comes out of the lens, increased in diameter by 7 times compared with the incident laser beam.

The telescopic laser beam expander for wavelengths of 1.06 μm and 0.633 μm has an optical system magnification of 7 times, exit pupil diameter of 3.6 mm, exit pupil removal of 20 ... 100 mm, and the mean-square deviation of the wavefront emerging from the telescopic system is 0.0039λ for wavelengths

1.06 μm and 0.633 μm, which indicates that the system has diffraction quality for the indicated wavelengths.

Information sources

1. US patent No. 5329404, publication 1992, IPC G02B 9/34

2. Patent RU No. 2209455 C2, publication 2001, IPC G02B 23/00 - prototype.

Claims (1)

A telescopic laser beam expander consisting of an optically coupled lens and an eyepiece, the lens comprising a biconvex lens, a biconcave lens and a positive lens, and the eyepiece is made in the form of a biconcave lens, characterized in that the biconcave and biconvex lens of the objective are separated by an air gap, the positive in the form of a meniscus facing a concave surface to the eyepiece.