Semiconductor laser coupling single-mode fiber system

Abstract

The utility model provides a semiconductor laser coupling single-mode fiber system, which comprises a semiconductor laser, a front lens group, a pinhole diaphragm, a rear lens group and a single-mode fiber which are sequentially arranged along a light path, the middle part of the pinhole diaphragm is provided with a pinhole, light beams emitted by the semiconductor laser are focused to the pinhole by the front lens group, and the light beams emitted by the rear lens group are focused to the single-mode fiber by the rear lens group. And the light beam enters the rear lens group through the small hole, and is focused to the end face of the single-mode optical fiber by the rear lens group. According to the semiconductor laser coupling single-mode optical fiber system, a lens structure is combined with small hole filtering, so that the optical coupling efficiency is ensured, stray light reflected to the semiconductor laser by specular reflection light and diffuse reflection light is reduced, and optical noise caused by mode jump is reduced.

Description

Technical Field

[0001] This utility model relates to the technical field of semiconductor lasers, and more precisely to a semiconductor laser coupled to a single-mode fiber optic system. Background Technology

[0002] Semiconductor lasers are lasers that use semiconductor materials as the gain medium and emit light by transitions between semiconductor energy bands. They have advantages such as wide wavelength coverage, small size, stable structure, strong radiation resistance, diverse pumping methods, high yield, good reliability, and easy high-speed modulation. They are widely used in many fields such as industry, military, medical, and communications.

[0003] The optical signal emitted by a semiconductor laser needs to be coupled into an optical fiber. Existing coupling methods include direct coupling and lens coupling. Lens coupling can be further divided into single-lens coupling and multi-lens coupling. Direct coupling has lower coupling efficiency. Compared with direct coupling, lens coupling has higher coupling efficiency, but the specular and diffuse reflection light generated by lens coupling will be reflected into the semiconductor laser, causing mode switching and resulting in high optical noise.

[0004] In summary, there is a need in this field to improve existing fiber coupling methods for semiconductor lasers to reduce optical noise while ensuring high coupling efficiency. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a semiconductor laser coupled single-mode fiber system, which uses a pinhole aperture to block specular reflection and diffuse reflection light, thereby reducing optical noise while ensuring high coupling efficiency.

[0006] To achieve the above objectives, this utility model provides a semiconductor laser coupled to a single-mode fiber system, comprising a semiconductor laser, a front lens group, a pinhole aperture, a rear lens group, and a single-mode fiber arranged sequentially along the optical path. The pinhole aperture has a small hole in the middle. The beam emitted from the semiconductor laser is focused by the front lens group onto the small hole. The beam passes through the small hole and enters the rear lens group, where it is focused by the rear lens group onto the end face of the single-mode fiber.

[0007] Preferably, the front lens group includes a front collimating lens and a front focusing lens arranged sequentially along the optical path. The front collimating lens collimates the incident light beam, and the collimated light beam is focused onto the small aperture by the front focusing lens.

[0008] Preferably, the front focusing lens focuses the light beam to form a circular or elliptical focused spot.

[0009] Preferably, the aperture of the small hole is at least 2.5 times the diameter of the focused spot.

[0010] Preferably, the front collimating lens is an aspherical collimating lens.

[0011] Preferably, the front focusing lens is a spherical lens, a cemented lens, or a combination of two cylindrical lenses.

[0012] Preferably, the rear lens group includes a rear collimating lens and a rear focusing lens arranged sequentially along the optical path. The light beam enters the rear collimating lens through the small hole, the rear collimating lens collimates the incident light beam, and the collimated light beam is focused by the rear focusing lens onto the end face of the single-mode optical fiber.

[0013] Preferably, the rear focusing lens is a spherical lens or an aspherical lens.

[0014] Preferably, the end face of the single-mode optical fiber is an inclined plane.

[0015] Preferably, the inclination angle of the end face is 8°.

[0016] Compared with the prior art, the advantages of the semiconductor laser coupled single-mode fiber system disclosed in this utility model are as follows: the semiconductor laser coupled single-mode fiber system utilizes a lens structure combined with a pinhole filter to reduce stray light reflected from specular reflection and diffuse reflection into the semiconductor laser while ensuring optical coupling efficiency, thereby reducing optical noise caused by mode switching. Attached Figure Description

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a schematic diagram of a semiconductor laser coupled to a single-mode fiber optic system according to this application. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] like Figure 1As shown, this application discloses a semiconductor laser-coupled single-mode fiber system comprising a semiconductor laser 1, a front lens group 2, a pinhole stop 3, a rear lens group 4, and a single-mode fiber 5 arranged sequentially along the optical path. The pinhole stop 3 has a pinhole 30 in its center. The beam emitted from the semiconductor laser 1 is focused by the front lens group 2 onto the pinhole 30. The beam passes through the pinhole 30 and enters the rear lens group 2, where it is focused onto the end face of the single-mode fiber 5. The pinhole 30 blocks light reflected from the rear lens group 2 and the end face of the fiber 5, reducing the probability of specular and diffuse reflection light being reflected into the semiconductor laser 1. This semiconductor laser-coupled single-mode fiber system uses lens coupling, resulting in high coupling efficiency. Furthermore, the pinhole stop 3 reduces the probability of specular and diffuse reflection light being reflected into the semiconductor laser 1, effectively solving the optical noise problem caused by reflected and stray light entering the semiconductor laser 1.

[0021] Specifically, the front lens group 2 includes a front collimating lens 21 and a front focusing lens 22 arranged sequentially along the optical path. The front collimating lens 21 collimates the incident light beam, and the collimated light beam is focused by the front focusing lens 22 onto the pinhole 30. The front collimating lens 21 is an aspherical collimating lens. The front focusing lens 22 can be a spherical lens, a cemented lens, or a combination of two cylindrical lenses. The front focusing lens 22 focuses the fast and slow axes of the light beam to form a circular focused spot. The aperture of the pinhole 30 is at least 2.5 times the diameter of the focused spot.

[0022] The rear lens group 4 includes a rear collimating lens 41 and a rear focusing lens 42 arranged sequentially along the optical path. The light beam enters the rear collimating lens 41 through the pinhole 30, and the rear collimating lens 41 collimates the incident light beam. The collimated light beam is then focused by the rear focusing lens 42 onto the end face of the single-mode fiber 5. The rear focusing lens 42 can be a spherical lens or an aspherical lens.

[0023] The end face of the single-mode fiber 5 is beveled, preferably with an inclination angle of 8°. By setting the end face as beveled, the focused beam can be prevented from not reflecting along the original optical path, further preventing reflected light from entering the semiconductor laser 1.

[0024] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A semiconductor laser coupled to a single-mode fiber system, characterized in that, The device includes a semiconductor laser, a front lens group, a pinhole aperture, a rear lens group, and a single-mode fiber arranged sequentially along the optical path. The pinhole aperture has a small hole in the middle. The beam emitted from the semiconductor laser is focused by the front lens group onto the small hole. The beam passes through the small hole and enters the rear lens group. The beam is then focused by the rear lens group onto the end face of the single-mode fiber.

2. The semiconductor laser coupled single-mode fiber system as described in claim 1, characterized in that, The front lens group includes a front collimating lens and a front focusing lens arranged sequentially along the optical path. The front collimating lens collimates the incident light beam, and the collimated light beam is focused onto the small aperture by the front focusing lens.

3. The semiconductor laser coupled single-mode fiber system as described in claim 2, characterized in that, The front focusing lens focuses the light beam to form a circular or elliptical focused spot.

4. The semiconductor laser coupled single-mode fiber system as described in claim 3, characterized in that, The aperture of the aperture is at least 2.5 times the diameter of the focused spot.

5. The semiconductor laser coupled single-mode fiber system as described in claim 2, characterized in that, The front collimating lens is an aspherical collimating lens.

6. The semiconductor laser coupled single-mode fiber system as described in claim 2, characterized in that, The front focusing lens is a spherical lens, a cemented lens, or a combination of two cylindrical lenses.

7. The semiconductor laser coupled single-mode fiber system as described in claim 1, characterized in that, The rear lens group includes a rear collimating lens and a rear focusing lens arranged sequentially along the optical path. The light beam enters the rear collimating lens through the small aperture, the rear collimating lens collimates the incident light beam, and the collimated light beam is focused by the rear focusing lens onto the end face of the single-mode optical fiber.

8. The semiconductor laser coupled single-mode fiber system as described in claim 7, characterized in that, The back focusing lens is either a spherical lens or an aspherical lens.

9. The semiconductor laser coupled single-mode fiber system as described in claim 1, characterized in that, The end face of the single-mode optical fiber is beveled.

10. The semiconductor laser coupled single-mode fiber system as described in claim 9, characterized in that, The inclination angle of the end face is 8°.

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