CN-122026209-A - Semiconductor side-pumped solid laser module based on multi-cavity reflection condensing cavity

CN122026209ACN 122026209 ACN122026209 ACN 122026209ACN-122026209-A

Abstract

The invention belongs to the technical field of semiconductor laser pumping solid lasers, and discloses a semiconductor side pumping solid laser module based on a multi-cavity reflection condensing cavity, which comprises a multi-cavity reflection condensing cavity (2), wherein an elliptical cavity and a semicircular cavity with inner walls as reflecting surfaces are formed in the multi-cavity reflection condensing cavity (2), an LD bar (1) and a thin rod type laser working medium (3) are arranged in the multi-cavity reflection condensing cavity (2), pump light rays emitted from the luminous point position of the LD bar (1) are converged at the axial center position of the thin rod type laser working medium (3) after being reflected by the inner walls, and residual pump light rays absorbed by the thin rod type laser working medium (3) are reflected back to the thin rod type laser working medium (3) again, so that the residual pump light energy is absorbed again, and efficient pumping is realized. The invention improves the utilization efficiency of the pumping light energy, and lightens the volume, weight and power consumption indexes of the pumping part of the laser under the same laser output power.

Inventors

GUO JIAWEI
WANG DI
WANG DONGDONG
CHENG JIA
WANG XINYU
WU XINYANG
WANG SONG
CAI HE
HAN JUHONG
YANG JIAO

Assignees

西南技术物理研究所

Dates

Publication Date: 20260512
Application Date: 20251224

Claims (10)

1. A semiconductor side pumping solid laser module based on a multi-cavity reflection condensing cavity is characterized by comprising a multi-cavity reflection condensing cavity (2), wherein an elliptical cavity and a semicircular cavity with inner walls being reflecting surfaces are formed in the multi-cavity reflection condensing cavity (2), an LD bar (1) and a thin rod type laser working medium (3) are arranged in the multi-cavity reflection condensing cavity (2), pump light rays emitted from the luminous point position of the LD bar (1) are converged at the axial center position of the thin rod type laser working medium (3) after being reflected by the inner walls, and residual pump light rays absorbed by the thin rod type laser working medium (3) are reflected back to the thin rod type laser working medium (3) again, so that the energy of the residual pump light is absorbed again, and efficient pumping is realized.
2. The semiconductor side-pumped solid laser module based on the multi-cavity reflection condensing cavity as claimed in claim 1, wherein an elliptical cavity and a semicircular cavity are formed in the multi-cavity reflection condensing cavity (2), an LD bar (1) and a thin rod type laser working medium (3) are arranged to form a single LD Shan Bangxing multi-cavity reflection condensing cavity (2), the elliptical cavity is located at the upper left position, the semicircular cavity is located at the lower right position, the luminous point position of the LD bar (1) and the axial center position of the thin rod type laser working medium (3) are respectively located at the left focus and the right focus of the ellipse, pump light emitted from the luminous point position of the LD bar (1) is totally converged at the axial center position of the thin rod type laser working medium (3) after being reflected by the upper part of the elliptical inner wall, residual pump light after being absorbed by the thin rod type laser working medium (3) reaches the lower right part of the semicircular inner wall, and is reflected back to the thin rod type laser working medium (3) by the original path, so that the residual pump light energy is absorbed again, and high efficiency pumping is realized.
3. The semiconductor side-pumped solid laser module based on the multi-cavity reflection condensing cavity according to claim 1, characterized in that two elliptical cavities and one semicircular cavity are formed in the multi-cavity reflection condensing cavity (2), one LD bar (1) and two thin rod-shaped laser working mediums (3) are arranged to form a single LD double rod-shaped multi-cavity reflection condensing cavity (2), and the single LD double rod-shaped multi-cavity reflection condensing cavity is formed by sequentially arranging an elliptical cavity at the upper left position, an elliptical cavity at the lower right position and a semicircular cavity at the upper right position from left to right; the left focus of the right ellipse is overlapped with the right focus of the left ellipse, the long axes of the two ellipses are parallel and overlapped, a thin rod type laser working medium (3) is respectively arranged at the left focus position and the right focus position of the right ellipse, pump light rays emitted by the LD bar (1) are reflected by the inner wall of the upper half part of the left ellipse of the multi-cavity reflection condensing cavity (2) and then converged on the thin rod type laser working medium (3) at the middle position, the absorbed residual pump light rays are incident on the inner wall of the lower half part of the right ellipse of the multi-cavity reflection condensing cavity (2), reflected and converged at the axle center position of the thin rod type laser working medium (3) at the right position and absorbed for the second time, the absorbed residual pump light rays are reflected back to the right thin rod type laser working medium (3) by the original path of the semicircular inner wall of the upper half part of the right side of the laser working medium and absorbed for the third time, the residual pump light rays are reflected by the inner wall of the lower half part of the right ellipse of the multi-cavity reflection condensing cavity (2) and converged on the thin rod type laser working medium (3) at the middle position, and absorbed a fourth time.
4. The semiconductor side-pumped solid laser module based on the multi-cavity reflection condensing cavity as claimed in claim 1, wherein two elliptic cavities and two semicircular cavities are formed in the multi-cavity reflection condensing cavity (2), two LD bars (1) and one thin rod type laser working medium (3) are arranged, the double LD single-rod type multi-cavity reflection condensing cavity (2) symmetrical in left-right structure is formed, the left upper position is an elliptic cavity, the right upper position is an elliptic cavity, the left lower semicircular cavity of the right upper elliptic cavity is opposite to the right lower semicircular cavity of the left upper elliptic cavity, the right focal point of the left upper elliptic cavity is coincident with the left focal point of the right upper elliptic cavity, the thin rod type laser working medium (3) is arranged at the coincident focal point position, after being reflected by the inner walls of the left upper half part and the right half part of the LD bars (1) on the left and the right side, residual pump light absorbed by the laser working medium is reflected back to the thin rod type laser working medium (3) by the inner walls of the left lower half part of the left upper half part and the left lower half part of the laser working medium from left upper half part to the right side, and the laser light emitted by the laser working medium (3) can be absorbed by the thin rod type laser working medium (1) again, and the laser light can be absorbed by the two times of the laser working medium (1).
5. The multi-cavity reflection condensing cavity-based semiconductor side pumped solid laser module as set forth in claim 1, wherein three elliptic cavities and two semicircular cavities are formed in the multi-cavity reflection condensing cavity (2), two LD bars (1) and two thin rod type laser working mediums (3) are arranged in the multi-cavity reflection condensing cavity (2), the double LD double rod type multi-cavity reflection condensing cavity (2) is formed, the left upper position is an elliptic cavity, the middle elliptical cavity, the left lower position is an elliptic cavity, the left focal point of the middle elliptical cavity is overlapped with the right focal point of the left upper ellipse, the right focal point of the middle elliptical cavity is overlapped with the left focal point of the right upper ellipse, the two overlapped focal points are respectively provided with a thin rod type laser working medium (3), the left lower position of the left thin rod type laser working medium (3) is provided with a semicircular cavity, the pumping light emitted by the LD bars (1) on the left side and the right side is respectively converged by the left upper elliptic part and the right lower elliptic part of the multi-cavity reflection condensing cavity (2), the laser light is respectively reflected by the left upper elliptic part and the left lower elliptic part of the left upper elliptic part and the left upper elliptic part of the multi-cavity (3), the thin rod type laser working medium (3) on the left upper side is respectively converged, the thin rod type laser working medium is respectively reflected by the left upper elliptic medium and the left upper elliptic part is respectively absorbed by the thin rod type laser working medium respectively, the residual pump light rays are reflected by semicircular inner walls of the upper half part on the right side and the lower half part on the left side of the laser working medium to the right side and the thin rod type laser working medium (3) on the left side respectively, absorbed for the third time, and the re-absorbed residual pump light rays are reflected by inner walls of the middle elliptical lower part and the upper part of the multi-cavity reflection condensing cavity (2) respectively, converged on the thin rod type laser working medium (3) on the left side and the right side and absorbed for the fourth time.
6. A semiconductor side pumped solid state laser module based on a multi-cavity reflective concentration cavity according to any of the claims 2 to 5, characterized in that the side surface of the slim rod laser working medium (3) is roughened to a translucent surface which has a part of diffuse reflection and diffuse transmission in addition to absorption, reflection and transmission of pump light.
7. A semiconductor side pumped solid state laser module based on a multi-cavity reflective concentration cavity according to claim 6, wherein the thin rod type laser working medium (3) is externally provided with a glass sleeve (5) concentric with the thin rod type laser working medium, and a gap between the thin rod type laser working medium and the glass sleeve is filled with flowing cooling liquid (4) to cool the thin rod type laser working medium (3).
8. A semiconductor side pumped solid state laser module based on a multi-cavity reflective concentrator as claimed in claim 7, wherein the inner and outer surfaces of the glass sleeve (5) are coated with an anti-reflection film for the wavelength of the pumping light.
9. The semiconductor side pumped solid laser module based on the multi-cavity reflection and condensation cavity according to claim 8, wherein the two ends of the glass sleeve (5) are respectively provided with a cooling liquid inlet and outlet (6), and the cooling liquid inlet and outlet (6) is connected with external water cooler equipment.
10. A semiconductor side pumped solid laser module based on a multi-cavity reflective condensing cavity according to claim 9, characterized in that the total reflection mirror (7) and the output mirror (8) are coaxially arranged at both ends of the thin rod type laser working medium (3) outside the composite reflective condensing cavity (2).

Description

Semiconductor side-pumped solid laser module based on multi-cavity reflection condensing cavity Technical Field The invention belongs to the technical field of semiconductor laser pumping solid lasers, and relates to a semiconductor side pumping solid laser module based on a multi-cavity reflection condensing cavity. Background Compared with the traditional lamp pump solid laser, the semiconductor pump solid laser has the advantages of high efficiency, less heat generation, small volume, light weight, long service life, good beam quality and the like, and has wide application in the fields of industry, civilian use, military and the like. Semiconductor pump solid lasers can be classified into two types, end-pumping and side-pumping, according to the directional relation between the incident direction of pump light and the outgoing direction of laser light. The two pumping modes have the characteristics and advantages and disadvantages, the end pumping is generally suitable for laser working media with smaller length-diameter ratio and higher laser oscillation threshold value, and better beam quality is easy to obtain, and the side pumping is generally suitable for laser working media with larger length-diameter ratio and lower laser oscillation threshold value, and higher output power is easier to obtain. For some highly doped high quantum defect laser working media, such as holmium doped fluoride crystals capable of directly pumping and outputting 3-5 μm mid-infrared band laser, waste heat generated by laser oscillation is large, and the laser working media are required to be designed into thin rods with diameters of about 1mm, and are matched with efficient side cooling, so that fatal influences of thermal lenses, thermally induced birefringence, thermal explosion and the like on laser output performance caused by thermal stress generated by internal temperature gradient can be avoided. However, for such highly doped high quantum defect slim rod laser working media, conventional end and side pumping schemes are difficult to implement. The high doping characteristic of the laser working medium enables the laser working medium to have a very high absorption coefficient for pump light, if an end-face pumping mode is adopted, the absorption of the pump light is concentrated near an incident end, and other parts of the laser working medium are hardly absorbed by the pump, so that laser oscillation is difficult to form, and if a side-face pumping mode is adopted, most of pump light cannot enter the laser working medium due to the small diameter of the laser working medium, the geometric optical efficiency of the pump is very low, and the laser oscillation is difficult to form. If the focusing of the side pumping light by the lens is attempted to be focused on the thin rod type laser working medium, the difficulty of optical processing and adjustment of the lens is very great, and the lens is difficult to realize. Moreover, in order to achieve higher laser output power, it may be necessary in practical engineering applications to pump one fine rod type laser working medium simultaneously using multiple groups of semiconductor pump sources, or conversely to pump multiple fine rod type laser working mediums simultaneously using one group of semiconductor pump sources, or a combination of the two, i.e. to pump multiple fine rod type laser working mediums simultaneously using multiple groups of semiconductor pump sources. This makes the structural design of semiconductor laser pumped solid state lasers difficult to implement with conventional pumping arrangements. Disclosure of Invention Object of the invention The invention aims to realize high-efficiency side pumping of a thin rod type laser working medium with high doping and high quantum defects, and can realize simultaneous pumping of a plurality of (or one) thin rod type laser working mediums by using a plurality of groups (or one group) of semiconductor pumping sources, so that the thin rod type laser working medium has the potential of generating high-performance laser output, and provides a semiconductor side pumping solid laser module based on a multi-cavity reflection condensing cavity. (II) technical scheme In order to solve the technical problems, the invention provides a semiconductor side pumping solid laser module based on a multi-cavity reflection condensing cavity, which takes a linear array semiconductor laser diode rake bar (hereinafter, abbreviated as LD bar) as a pumping source, utilizes the divergence angle range of the linear array semiconductor laser diode rake bar in the fast axis luminous direction to approximate to the luminous characteristic of a point light source, utilizes the special geometrical optical characteristics of an elliptic cavity and a semicircular cavity, adopts the special spatial combination of the elliptic cavity and the semicircular cavity, ensures that the pumping light energy emitted by the LD bar can be absorbed by