Laser device
By installing semiconductor laser, optical elements, and temperature elements on the laser workbench, and using the interval design of the maintenance component and Prague grille body, the laser device deformation problem in temperature changes, realizing the stability and efficient forming of laser.
Patent Information
- Application Number
- CN202380046318.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-06-20
- Filing Date
- 2023-06-16
- Publication Date
- 2025-01-28
AI Technical Summary
The laser device with a laser table will deform when the temperature changes, resulting in a decrease in the efficiency of the laser device because the temperature gradient and thermal expansion coefficient of different components will cause deformation.
Install semiconductor laser, first optical elements and temperature elements on the laser workbench, and install the Prague grille by maintaining the component to separate it from the laser workbench, so as to use temperature elements for favorable temperature adjustment, keep the Prague grid body relative The expected location of the laser axis.
By maintaining the deformation of the component compensation for the laser workbench, it is ensured that the Prague grille body has a stable position compared to the laser axis, reducing the impact of deformation on the efficiency of laser device, and maintaining the stability and efficient forming of laser.
Smart Images
Figure CN119384775A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a laser device with a laser workbench, on which a semiconductor laser is arranged for emitting laser light along a laser axis. Background Art
[0002] Laser devices with laser tables deform when the temperature changes. In particular, temperature gradients and thermal expansion coefficients of the various components of the laser device are responsible for these deformations. These deformations have a direct impact on the efficiency of the laser device, since components of the laser device, such as optical elements and semiconductor lasers, are adjusted relative to the laser axis. Summary of the invention
[0003] It is proposed to provide a laser device provided with a laser workbench, on which are mounted: a semiconductor laser for emitting laser along a laser axis; a first optical element for forming the laser; and a temperature element for adjusting the temperature of the laser device, wherein the laser device has a holding element on which a Bragg grating body is mounted, and the Bragg grating body is spaced apart from the laser workbench.
[0004] The Bragg grating body includes a Bragg grating which stabilizes laser light based on Bragg reflection.
[0005] The temperature element can be a Peltier element or a microchannel cooler. In order to enable advantageous temperature regulation by means of the temperature element, the thermistor can be located in particular near the semiconductor laser or in direct contact with the semiconductor laser. The thermistor can directly measure the temperature of the laser diode. The temperature signal of the thermistor is used by the evaluation unit of the control loop in which the thermistor and the temperature element are located to regulate the temperature of the temperature element.
[0006] The first optical element may be a lens for collimating the laser light.
[0007] Due to the spacing of the Bragg grating body from the laser table, deformations of the laser table do not have a direct effect on the position of the Bragg grating body. The holding element compensates for deformations of the laser table so that the desired relative position of the Bragg grating body with respect to the laser axis is largely maintained. Slight deformations are still possible. However, such deformations occur only to such an extent that the efficiency of the laser device is hardly impaired.
[0008] Advantageous embodiments and developments of the invention are achieved by the measures specified in the dependent claims.
[0009] Advantageously, the temperature element is mounted on different sides, preferably opposite sides, of the laser table relative to the optical element. Here, the laser table is particularly arranged between the temperature element and the laser diode, so that heat transfer from the laser diode to the temperature element preferably occurs via the laser table.
[0010] The holding element can be mounted on a side of the optical element facing away from the laser table. Here, the holding element can be mounted on a side of the surface of the optical element facing away from the laser table. This enables the Bragg grating body to be spaced apart from the laser table depending on the height of the optical element. The height of the optical element refers to the surface of the laser table on which the optical element is mounted.
[0011] In order to enable particularly efficient shaping of the laser light, a second optical element may be provided, wherein the Bragg grating body may be arranged between the two optical elements. In a special embodiment, the holding element may be arranged on the two optical elements, wherein the optical elements have the same height.
[0012] In one embodiment, the Bragg grating body can be mounted on a side of the holding element facing the laser table, wherein the Bragg grating body is spaced apart from the surface on which the optical element is mounted. Thus, the Bragg grating body is not in direct contact with the laser table, so that any deformation of the laser table is compensated by the holding element.
[0013] In a particular embodiment, the holding element can have at least one distance segment mounted on the laser table so that the holding element is spaced apart from the laser table. The distance segment is arranged between the holding element and the laser table. Preferably, the distance segment has a height of 100 to 500 micrometers.
[0014] In an alternative embodiment, the Bragg grating body can be mounted on the side facing away from the laser table.This embodiment can be combined with the previous embodiment, so that for example two Bragg grating bodies are provided which are mounted on different sides of one or more holding elements.
[0015] Advantageously, a third optical element is provided, which is arranged to collimate the laser and is located between the first optical element and the semiconductor laser. The third optical element can be mounted on the semiconductor laser so that the third optical element is not mounted directly on the laser table. The third optical element is arranged to collimate the laser in a direction perpendicular to the surface of the laser table on which the first optical element is located. The collimation of the laser perpendicular to the collimation of the third optical element is generated by the first optical element. The second optical element is used, in particular in the form of a thin film polarizer, to filter out perpendicular polarizations, thereby allowing parallel polarizations to pass.
[0016] In particular, the Bragg grating body is spaced apart from at least one optical element and from the laser stage such that the Bragg grating body is in direct contact only with the holding element.The Bragg grating body may be spaced apart from each optical element such that there is no direct contact between the optical element and the Bragg grating body.
[0017] In a special embodiment, the holding element is a housing section of the laser device. As a result, a separate component may not be required, and the housing of the laser device may take over the function of the holding element.
[0018] Particularly preferably, the holding element comprises a ceramic material. This can be elastic. Preferably, the holding element is plate-shaped or rod-shaped.
[0019] Preferably, a resonator is formed between the cavity of the semiconductor laser and the Bragg grating body, which extends along the laser axis and stabilizes the laser mode of the laser. Here, the rear end facet of the cavity of the semiconductor laser can be used as one boundary of the resonator, and the Bragg grating of the Bragg grating body forms another boundary. Preferably, the output end face of the laser from which the laser is emitted has an anti-reflection coating. The rear end facet is the back wall of the cavity in the semiconductor laser, and there is an emission area on the output end facet of the semiconductor laser, wherein the emission area is opposite to the rear end facet. The laser leaves the semiconductor laser from the emission area. An external resonator for realizing narrowband operation is constructed between the rear end facet of the cavity of the semiconductor laser and the Bragg grating of the Bragg grating body. The resulting wavelength range is 1pm to 100pm, in particular 1pm to 50pm.
[0020] The scope of the present invention is limited only by the claims. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The present invention will be described in more detail below based on embodiments with reference to the associated drawings. The directions in the following description should be understood according to the reading direction of the drawings.
[0022] It shows:
[0023] Figure 1 A first embodiment in which the retaining element is arranged on the optical element, and
[0024] Figure 2 A second embodiment in which the holding element is mounted on the laser table by means of a distance element. DETAILED DESCRIPTION
[0025] The drawings show a laser device 10, which includes a laser workbench 12, on which a semiconductor laser 14 is mounted, which is configured to emit laser light along a laser axis 16. A first optical element 181 and a second optical element 182 are arranged along the laser axis 16 and are configured to shape the laser light. The first optical element 181 is arranged between the second optical element 182 and the semiconductor laser 14.
[0026] The optical element 181 is configured to collimate the laser along the laser axis 16. In addition, a third optical element 183 is provided, which is configured to collimate the laser. The third optical element is positioned between the first optical element 181 and the semiconductor laser 14. The third optical element 183 can be mounted on the semiconductor laser 14 so that the third optical element is not directly mounted on the laser workbench 12. Alternatively, the third optical element 183 can also be arranged directly on the laser workbench 12.
[0027] The third optical element 183 is configured to collimate the laser light in a direction perpendicular to the surface of the laser table 12 on which the first optical element 181 is located. The collimation of the laser light perpendicular to the collimation of the third optical element 183 is generated by the first optical element 181. The second optical element 182, in particular in the form of a thin film polarizer, is used to filter out perpendicular polarization, thereby allowing parallel polarization to pass.
[0028] The optical elements 181 , 182 , 183 and the semiconductor laser 14 are arranged on a common side of the laser table 12 , wherein the first optical element 181 and the second optical element 182 are mounted on the surface 20 of the laser table 12 .
[0029] A temperature element 22 is mounted on the opposite side of the laser table 12 for adjusting the temperature of the laser device 10. The temperature element 22 may be a Peltier element or a microchannel cooler. The temperature element is in contact with the surface of the laser table 12. The laser table 12 is arranged between the temperature element 22 and the laser diode 14, so that heat transfer from the laser diode 14 to the temperature element 22 is performed via the laser table 12.
[0030] The laser device 10 has a holding element 24 which is provided for a Bragg grating body 26 . The Bragg grating body 26 is mounted on the holding element 24 , wherein the Bragg grating body is spaced apart from the laser table 12 , so that the Bragg grating body is not in direct contact with the laser table 12 .
[0031] The Bragg grating body includes a Bragg grating which stabilizes laser light based on Bragg reflection.
[0032] Due to the spacing of the Bragg grating body 26 from the laser table 12, deformations of the laser table 12 do not directly affect the position of the Bragg grating body 26. The holding element 26 compensates for deformations of the laser table 12 so that the desired relative position of the Bragg grating body 26 with respect to the laser axis 16 is largely maintained.
[0033] The holding element 24 preferably comprises an elastic ceramic material. Here, the holding element 24 is designed in a plate-like or rod-like manner.
[0034] Preferably, an external resonator is constructed between the cavity 13 of the semiconductor laser 14 and the Bragg grating body 26, which extends along the laser axis 16. The resonator stabilizes the laser mode of the laser, which is predetermined by the Bragg grating. Here, the Bragg grating is used as an output element of the external resonator, so that only a very narrow-band laser line in the picometer range, in particular 1pm to 100pm, preferably 1pm to 50pm is emitted. Here, the semiconductor laser 14 includes the following cavity, which has a rear end face and an output end face opposite to the rear end face, wherein the two end faces are arranged along the laser axis 16. The rear end face is the rear wall of the cavity 13 of the semiconductor laser 14, which is opposite to the emission area on the output end face of the semiconductor laser 14. The laser leaves the emission area. The rear end face represents a first boundary relative to the laser axis 16 of the resonator, and the Bragg grating of the Bragg grating body 26 forms a second boundary.
[0035] Figure 1 The laser device 10 shows a holding element 24 which is arranged on the first optical element 181 and the second optical element 182 so that the optical elements 181, 182 are arranged between the holding element 24 and the laser table 12. The holding element 24 is mounted on the side of the respective optical element 181, 182 facing away from the laser table 12.
[0036] The Bragg grating body 26 protrudes from the holding element 24 in the direction of the laser table 12. Here, the Bragg grating body 26 does not touch the laser table 12. Furthermore, the Bragg grating body 26 is arranged between the first optical element 181 and the second optical element 182, wherein all optical elements 181, 182, 183 and the Bragg grating body 26 are arranged along the laser axis 16. Preferably, the two optical elements 181, 182 have the same height and the holding element 24 is aligned parallel to the surface 20 of the laser table 12.
[0037] The Bragg grating body 26 does not contact the optical elements 181 , 182 . The Bragg grating body 26 protrudes freely from the holding element 24 .
[0038] In another embodiment, only the first optical element 181 can shape the laser. Instead of the second optical element 182, a support element that does not shape the laser can be used. For example, a material that is transparent to the laser can be used, which also has a recessed portion through which the laser can pass unimpeded. For example, a glass cuboid with a hole can be used, where the hole represents the recessed portion.
[0039] Figure 2 A second embodiment is shown, in which the holding element 24 is mounted on the laser table 12 with at least one distance segment 28, so that the holding element 24 is spaced apart from the surface 20 of the laser table 24. The distance segment 28 is arranged between the holding element 24 and the laser table 12 and can have the shape of a disk. Preferably, the distance segment 28 has a height of 100 to 500 micrometers. Preferably, a plurality of distance segments 28 are provided, which are arranged on the underside of the holding element 24, so that a free space 30 is formed between the distance segment 28 of the surface 20 of the laser table 12 and the underside 32 of the holding element 24.
[0040] The Bragg grating body 26 is mounted on the side facing away from the laser workbench 12. The Bragg grating body 26 is also independent and spaced apart from the laser workbench 12. Here, the Bragg grating body 26 protrudes upward. The Bragg grating body is arranged between the first optical element 181 and the second optical element 182.
[0041] Both embodiments can be realized with only one optical element 181. Furthermore, the embodiments can be combined with one another so that, for example, two Bragg grating bodies 26 are provided, in particular in connection with several semiconductor lasers 14. The Bragg grating bodies 26 can be mounted on different sides of one or more holding elements 24.
[0042] Furthermore, the retaining element 24 may alternatively be formed by a housing section (not shown) of the housing of the laser device 10 .
[0043] In general, the second optical element 182 can also be omitted.
[0044] A focusing lens can be arranged after the second optical element 182 or, if the second optical element is omitted, after the Bragg grating body 26, which couples the laser light into the waveguide. The focusing lens can be mounted on the housing of the laser device 10. The focusing lens can be glued to the housing. Thus, the focusing lens is decoupled from the structure of the laser table 12. Alternatively, the focusing lens can be glued directly to the laser table as the last beam-forming element before the waveguide.
Claims
1. A laser device (10), comprising a laser workbench (12), on which are mounted: a semiconductor laser (14) for emitting laser light along a laser axis (16); a first optical element (181) for forming the laser light; and a temperature element (22) for adjusting the temperature of the laser device (10), wherein: The laser device (10) has a holding element (24) on which a Bragg grating body is mounted, the Bragg grating body being spaced apart from the laser table (12).
2. The laser device (10) according to claim 1, characterized in that The temperature element (22) is mounted on a side of the laser table (12) different from the optical element (181, 182, 183), preferably on the opposite side.
3. The laser device (10) according to claim 1 or 2, characterized in that: The holding element (24) is mounted on the optical element (181, 182, 183) on a side facing away from the laser table (12).
4. The laser device (10) according to any one of the preceding claims, characterized in that A second optical element (182) is provided, wherein the Bragg grating body (26) is arranged between the two optical elements (181, 182).
5. The laser device (10) according to any one of the preceding claims, characterized in that The Bragg grating body (26) is mounted on a side of the holding element (24) facing the laser workbench (12), wherein the Bragg grating body (26) is spaced apart from a surface (20) on which the optical element (181, 182, 183) is mounted.
6. The laser device (10) according to any one of the preceding claims, characterized in that The holding element (24) has at least one distance section (28) mounted on the laser table (12) such that the holding element (24) is spaced apart from the laser table (12).
7. The laser device (10) according to claim 6, characterized in that The distance section (28) has a height of 100 micrometers to 500 micrometers.
8. The laser device (10) according to claim 6 or 7, characterized in that The Bragg grating body (26) is mounted on the holding element (24) on a side of the holding element (24) facing away from the laser table (12).
9. The laser device (10) according to any one of the preceding claims, characterized in that A third optical element (183) is provided, which is used to collimate the laser light and is located between the first optical element (181) and the semiconductor laser (14).
10. The laser device (10) according to any one of the preceding claims, characterized in that The Bragg grating body (26) is spaced apart from at least one optical element (181, 182, 183) and from the laser workbench (12), so that the Bragg grating body (26) is in direct contact only with the holding element (24).
11. The laser device (10) according to any one of claims 1 to 5, characterized in that The holding element (24) is a housing section of the laser device (10).
12. The laser device (10) according to any one of the preceding claims, characterized in that The retaining element (24) contains a ceramic material.
13. The laser device (10) according to any one of the preceding claims, characterized in that The retaining element (24) is configured in a plate shape or a rod shape.
14. The laser device (10) according to any one of the preceding claims, characterized in that A resonator is formed along the laser axis (16) between the cavity (13) of the semiconductor laser (14) of the Bragg grating body (26), the resonator being used for stabilizing the laser mode of the laser light.