Narrow-band locking device for a laser and process for manufacturing same
By combining a displacement compensation component and a piezoelectric ceramic driver, the distance between the laser chip and the frequency doubling crystal is automatically adjusted, solving the positional shift problem caused by temperature changes, improving the narrowband wavelock stability and thermal conductivity of the laser, and ensuring high efficiency and stability of laser output.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- EASTERN LIAONING UNIV
- Filing Date
- 2026-05-11
- Publication Date
- 2026-07-24
AI Technical Summary
In existing narrowband wavelock devices for lasers, the spacing between the laser chip and the frequency doubling crystal shifts when the temperature changes, resulting in decreased coupling efficiency and poor wavelock stability. Furthermore, insufficient thermal conductivity affects output power and bandwidth.
The design combines a displacement compensation component and a piezoelectric ceramic actuator. It utilizes two connecting plates with different coefficients of thermal expansion to automatically adjust the distance between the laser chip and the frequency doubling crystal. Temperature uniformity is achieved through a semiconductor cooler and a heat-conducting layer. Combined with a beam-shaping lens group and lens structure, the stability of the laser output is ensured.
Automatic compensation of the distance between the laser chip and the frequency doubling crystal was achieved, which improved the stability of narrowband wavelock and the accuracy of laser output, reduced the impact of temperature changes on device performance, and improved thermal conductivity.
Smart Images
Figure CN122456286A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of laser technology, and in particular to a narrowband wavelock device for lasers and its fabrication process. Background Technology
[0002] Narrowband wavelocking technology for lasers is crucial for achieving monochromatic and stable laser output. Its core lies in ensuring the relative positional accuracy between the laser chip and the frequency-doubling crystal, thereby guaranteeing the narrowband wavelocking effect after frequency doubling and filtering. In existing technologies, narrowband wavelocking devices for lasers typically fix the frequency-doubling crystal on a base. However, during laser operation, the laser chip, base, and frequency-doubling crystal all experience temperature changes. The differences in the thermal expansion coefficients of these components cause a shift in the distance between the laser chip and the frequency-doubling crystal, affecting the laser coupling efficiency and wavelocking stability, leading to problems such as increased wavelocking bandwidth and output power fluctuations. Simultaneously, existing devices have poor thermal conductivity, preventing the rapid and uniform dissipation of heat generated by the laser chip, further exacerbating the positional shift caused by temperature unevenness. Therefore, there is an urgent need for a narrowband wavelocking device for lasers that can automatically compensate for temperature-induced positional shifts and provides uniform thermal conductivity. Summary of the Invention
[0003] The main objective of this invention is to provide a narrowband wavelock device for lasers and its fabrication process to solve the above-mentioned problems.
[0004] To achieve the above objectives, the present invention provides a narrowband wavelock device for a laser, comprising: A housing, wherein a base and a light-transmitting window are detachably connected to the housing; A laser chip is disposed on the base, and the light emission direction of the laser chip faces the light-transmitting window; A frequency doubling crystal holder is slidably disposed on the base and located between the laser chip and the light-transmitting window for holding the frequency doubling crystal; A displacement compensation component, one end of which is connected to the base and the other end of which is connected to the frequency doubling crystal holder, is used to automatically adjust the distance between the laser chip and the frequency doubling crystal holder according to temperature changes.
[0005] Furthermore, the displacement compensation component includes a first connecting plate and a second connecting plate combined together. The composite direction of the first connecting plate and the second connecting plate is perpendicular to the light emission direction of the laser chip. The first connecting plate and the second connecting plate have different coefficients of thermal expansion. The first end of the displacement compensation component is rotatably connected to the base, and the second end is rotatably connected to the frequency doubling crystal holder.
[0006] Furthermore, the device is characterized by further including a piezoelectric ceramic actuator, which is disposed at the second end of the displacement compensation assembly and rotatably connected to the frequency doubling crystal holder.
[0007] Furthermore, the base includes a first thermally conductive layer and a second thermally conductive layer, and a semiconductor cooler is disposed between the first thermally conductive layer and the second thermally conductive layer.
[0008] Furthermore, the first thermally conductive layer is an aluminum nitride ceramic plate, with a heat spreader integrated inside or on the bottom surface. The heat spreader is at least one of a graphene thermally conductive sheet, a heat spreader plate, or a sputtered copper thermally conductive channel, used to uniformly conduct the cooling energy generated by the semiconductor cooler.
[0009] Furthermore, the laser chip is characterized by having a narrow-band filter on its light-emitting surface and a beam-shaping lens assembly on its base. The beam-shaping lens assembly includes a negative lens and a positive lens arranged sequentially along the light-emitting direction, which are used to shape the laser output from the frequency-doubling crystal.
[0010] Furthermore, the base is provided with a V-shaped track along the light emission direction, and the bottom of the frequency doubling crystal holder is provided with ball bearings adapted to the V-shaped track, the ball bearings being slidably connected to the V-shaped track.
[0011] A fabrication process for a narrowband wavelock device for a laser, used to fabricate the narrowband wavelock device for the laser as described above, characterized by comprising the following steps: S1. Base Fabrication: An aluminum nitride ceramic material is selected to fabricate the first thermally conductive layer. A heat spreader is integrated inside or on the bottom surface of the first thermally conductive layer. The heat spreader is made of at least one of graphene thermally conductive sheet, heat spreader plate, or sputtered copper thermally conductive channel and is fixed by sputtering, bonding, or embedded installation. A metal material with excellent thermal conductivity is selected to fabricate the second thermally conductive layer. The semiconductor cooler is fixed between the first and second thermally conductive layers and bonded with thermally conductive adhesive to ensure good thermal conductivity and form a complete base. A V-shaped track along the light emission direction is processed on the base and the track surface is polished to reduce sliding friction. S2. Displacement compensation component preparation: Select two metal materials with different coefficients of thermal expansion, process them into a first connecting plate and a second connecting plate respectively, and combine them together by welding or bonding, with the composite direction perpendicular to the light output direction of the laser chip; Rotary connecting holes are processed at both ends of the displacement compensation component for connection with the base and the frequency doubling crystal holder. S3. Preparation of frequency doubling crystal clamp: The main body of the clamp is made of high temperature and high strength material. Ball bearings adapted to the V-shaped track are installed at the bottom of the clamp to ensure that the ball bearings can slide smoothly in the track. A clamping groove is machined inside the clamp to fix the frequency doubling crystal. An elastic buffer layer is set on the inner wall of the clamping groove to avoid damage to the frequency doubling crystal. S4. Component Assembly: Fix the laser chip to the first thermally conductive layer of the base using thermally conductive adhesive, ensuring that the light emission direction of the laser chip faces the preset light-transmitting window position; attach a narrow-band filter to the light emission surface of the laser chip, ensuring that the filter is tightly attached to the light emission surface without offset; rotatably connect the first end of the displacement compensation component to the base via a rotating shaft, and connect the second end to the piezoelectric ceramic driver, which is then rotatably connected to the frequency doubling crystal holder via a rotating shaft; fix the frequency doubling crystal in the clamping groove of the holder, and adjust the position of the holder so that the frequency doubling crystal is located in the optical path between the laser chip and the light-transmitting window; fix the beam shaping lens group on the base, so that the negative lens and the positive lens are arranged sequentially along the light emission direction, and the optical axis coincides with the light emission axis of the laser chip; S5. Housing Assembly: The assembled base is detachably connected to the housing using bolts. The light-transmitting window is installed, ensuring that it is aligned with the laser output direction and that the housing is well-sealed to prevent dust and moisture from entering. The entire device is debugged, and the temperature response performance of the displacement compensation component, the fine-tuning accuracy of the piezoelectric ceramic driver, the beam shaping effect, and the narrowband wave-locking performance are tested to ensure that the device meets the design requirements.
[0012] The present invention has the following beneficial effects: This invention incorporates a displacement compensation component that utilizes a composite structure of two connecting plates with different coefficients of thermal expansion to automatically compensate for the distance between the laser chip and the frequency doubling crystal when the temperature changes. This counteracts the positional shift caused by thermal expansion and contraction. Combined with the active fine-tuning of the piezoelectric ceramic actuator, it significantly improves the stability of the narrowband wavelocked laser. Attached Figure Description
[0013] Figure 1 This is an overall schematic diagram of a narrowband wavelock device for a laser according to the present invention.
[0014] Figure 2 This is a schematic diagram of the base of a narrowband wavelock device for a laser according to the present invention.
[0015] Among them, 1-shell; 2-laser chip; 3-frequency doubling crystal holder; 4-base; 41-first heat-conducting layer; 42-second heat-conducting layer; 43-semiconductor cooler; 5-light-transmitting window; 6-first connecting plate; 7-second connecting plate; 8-narrow band filter; 9-negative lens; 10-positive lens; 11-V-shaped track. Detailed Implementation
[0016] To achieve the above objectives and effects, the technical means and structure adopted by the present invention will be described in detail with reference to the accompanying drawings, focusing on the features and functions of the preferred embodiments of the present invention.
[0017] like Figures 1-2 As shown, this invention provides a narrowband wavelock device for a laser, including a housing 1, a laser chip 2, a frequency doubling crystal holder 3, and a displacement compensation assembly. The housing 1 contains a base 4 and a light-transmitting window 5, which are detachably connected to the housing 1. This detachable connection facilitates the assembly, maintenance, and repair of the device. The light-transmitting window 5 is used for laser output and also serves to seal and prevent dust from affecting the internal components of the housing 1 from external environmental influences. The laser chip 2 is mounted on the base 4, with its light emission direction facing the light-transmitting window 5. The laser chip 2 acts as a laser emission source, and its light emission direction is precisely aligned with the light-transmitting window. 5. Ensure smooth laser output; the frequency doubling crystal holder 3 is slidably mounted on the base 4 and located between the laser chip 2 and the light-transmitting window 5, and is used to hold the frequency doubling crystal. The frequency doubling crystal is used to perform frequency doubling processing on the laser emitted by the laser chip 2. The slidable holder makes it easy to adjust the position of the frequency doubling crystal to adapt to different working requirements; one end of the displacement compensation component is connected to the base 4 and the other end is connected to the frequency doubling crystal holder 3, and is used to automatically adjust the distance between the laser chip 2 and the frequency doubling crystal holder 3 according to temperature changes, to offset the thermal expansion and contraction displacement caused by temperature changes, and to ensure the stability of their relative positions.
[0018] Specifically, the displacement compensation component includes a first connecting plate 6 and a second connecting plate 7 combined together. The composite direction of the first connecting plate 6 and the second connecting plate 7 is perpendicular to the light emission direction of the laser chip 2. The first connecting plate 6 and the second connecting plate 7 have different coefficients of thermal expansion. The first end of the displacement compensation component is rotatably connected to the base 4, and the second end is rotatably connected to the frequency doubling crystal holder 3. Due to the difference in the coefficients of thermal expansion of the first connecting plate 6 and the second connecting plate 7, when the temperature changes, their expansion and contraction amounts are different, resulting in slight bending. This causes the frequency doubling crystal holder 3 to slide along the base 4, achieving automatic compensation of the distance between the laser chip 2 and the frequency doubling crystal. The structure is simple, the compensation is accurate, and no additional power is required.
[0019] Preferably, the assembly also includes a piezoelectric ceramic actuator, which is disposed at the second end of the displacement compensation component and rotatably connected to the frequency doubling crystal holder 3. The piezoelectric ceramic actuator can be actively fine-tuned according to actual needs, and combined with the passive temperature compensation of the displacement compensation component, it further improves the accuracy and flexibility of the spacing adjustment, ensuring that the relative position of the laser chip 2 and the frequency doubling crystal remains optimal under different temperature environments and working conditions, thereby improving stability.
[0020] Specifically, the base 4 includes a first thermally conductive layer 41 and a second thermally conductive layer 42, with a semiconductor cooler 43 disposed between the first thermally conductive layer 41 and the second thermally conductive layer 42. The semiconductor cooler 43 can achieve active temperature control, adjust the temperature of the base 4, reduce the temperature variation range, and, in conjunction with the displacement compensation component, further improve the temperature stability of the device; the first thermally conductive layer 41 and the second thermally conductive layer 42 are used to conduct heat, ensuring that the cold or heat of the semiconductor cooler 43 can be quickly transferred, achieving uniform temperature of the entire base 4.
[0021] Specifically, the first thermally conductive layer 41 is an aluminum nitride ceramic plate, with a heat spreader integrated inside or on its bottom surface. The heat spreader is at least one of a graphene thermally conductive sheet, a heat spreader plate, or a sputtered copper thermally conductive channel, used to uniformly conduct the cold energy generated by the semiconductor cooler 43. The aluminum nitride ceramic plate has excellent thermal conductivity and insulation properties, making it suitable as a mounting carrier for the laser chip 2 and the frequency doubling crystal holder 3. The heat spreader can further optimize the thermal conductivity, avoid excessively high or low local temperatures on the base 4, ensure that the laser chip 2 and the frequency doubling crystal operate in a stable temperature environment, and reduce the impact of temperature fluctuations on device performance.
[0022] Specifically, the light-emitting surface of the laser chip 2 is also equipped with a narrowband filter 8, which is used to filter stray light in the laser, improve the monochromaticity of the laser, and enhance the narrowband wave-locking effect. The base 4 is also equipped with a beam shaping mirror group, which includes a negative lens 9 and a positive lens 10 arranged sequentially along the light-emitting direction. It is used to shape the laser output by the frequency doubling crystal. The negative lens 9 is used to diverge the laser beam, and the positive lens 10 is used to converge the laser beam. The two work together to shape the frequency-doubled laser into a parallel beam or a beam of a specific size, improve the laser beam quality, and meet the needs of subsequent use.
[0023] Specifically, the base 4 is provided with a V-shaped track 11 along the light emission direction, and the bottom of the frequency doubling crystal holder 3 is provided with ball bearings adapted to the V-shaped track 11, which are slidably connected to the V-shaped track 11. The cooperation between the V-shaped track 11 and the ball bearings ensures that the frequency doubling crystal holder 3 slides smoothly along the light emission direction, avoiding problems such as offset and jamming during the sliding process, ensuring the positional accuracy of the frequency doubling crystal, and reducing sliding friction to extend the service life of the device.
[0024] The present invention also provides a fabrication process for the above-mentioned narrowband wavelock device for lasers, comprising the following steps: S1. Base Preparation: Aluminum nitride ceramic material was selected and precision ground to form a first thermally conductive layer with a thickness of 5mm. A graphene thermally conductive sheet with a thickness of 0.2mm was attached to the bottom surface of the first layer as a temperature equalization layer using high-temperature resistant thermally conductive adhesive. After compaction, the layer was cured at 120℃ for 2 hours. A second thermally conductive layer with a thickness of 4mm was formed using copper alloy material. The semiconductor cooler was fixed between the first and second thermally conductive layers using thermally conductive adhesive. After curing, the thermal conductivity was tested to ensure uniform heat conduction. A V-shaped track with an included angle of 90° was machined on the base using a CNC milling machine. After machining, the track surface was polished until the roughness Ra≤0.8μm.
[0025] Preferably, a first step surface and a second step surface are prepared on the upper surface of the first thermal conductive layer, with a height difference between them; the laser chip is fixed to the first step surface, the first end of the displacement compensation component is fixed to the step between the first step surface and the second step surface, and the frequency doubling crystal holder is set on the second step surface, so that the light-emitting end face of the laser chip and the incident end face of the frequency doubling crystal are at the same horizontal optical axis height.
[0026] S2. Displacement compensation component preparation: Select stainless steel plate and copper plate, and process them into a first connecting plate and a second connecting plate with a thickness of 2mm and a size of 30mm×10mm respectively. Clean the mating surfaces of the two plates, and combine them by laser welding at a welding temperature of 1800℃. After welding, perform annealing treatment to eliminate welding stress.
[0027] S3. Preparation of frequency doubling crystal clamping frame: Quartz material is selected and the main body of the clamping frame is made through precision machining. A ball bearing mounting groove is machined at the bottom, and the ball bearing is embedded in the mounting groove to ensure that the ball bearing can rotate flexibly. A clamping groove matching the crystal is machined inside the clamping frame, and a silicone buffer layer with a thickness of 0.5mm is pasted on the inner wall of the groove.
[0028] S4. Component Assembly: Fix the semiconductor laser chip to the first thermally conductive layer of the base using thermally conductive adhesive, align it with the preset position, and ensure that the light output direction faces the light transmission window; attach a narrow-band filter to the light output surface of the laser chip, fix it with UV adhesive, and check whether the filter is misaligned after curing; connect the first end of the displacement compensation component to the base through a rotating shaft to ensure flexible rotation, and connect the second end to the piezoelectric ceramic driver. The other end of the piezoelectric ceramic driver is connected to the frequency doubling crystal holder through a rotating shaft; place the KTP crystal into the clamping slot of the holder, adjust the clamping force to ensure that the crystal is firmly fixed and not damaged; fix the negative lens and positive lens to the base in sequence, and adjust their positions so that the optical axis coincides with the light output axis of the laser chip.
[0029] S5. Housing Assembly: Connect the assembled base to the housing with bolts, install the quartz glass light-transmitting window, and seal it with sealant to ensure good housing sealing; debug the device, and test the displacement compensation component's compensation amount of 0.1~0.5mm and the piezoelectric ceramic actuator's fine adjustment accuracy of 0.01μm when the test temperature is within the range of -10℃~60℃; test the laser output bandwidth of 8~10nm and the beam divergence angle ≤0.5mrad, which meets the design requirements.
[0030] The above description is only a preferred embodiment of the present invention and not all embodiments. Anyone should know that structural changes made under the guidance of the present invention, and any technical solutions that are the same as or similar to the present invention, are within the protection scope of the present invention.
Claims
1. A narrowband wavelock device for a laser, characterized in that, include: A housing, wherein a base and a light-transmitting window are detachably connected to the housing; A laser chip is disposed on the base, and the light emission direction of the laser chip faces the light-transmitting window; A frequency doubling crystal holder is slidably disposed on the base and located between the laser chip and the light-transmitting window for holding the frequency doubling crystal; A displacement compensation component, one end of which is connected to the base and the other end of which is connected to the frequency doubling crystal holder, is used to automatically adjust the distance between the laser chip and the frequency doubling crystal holder according to temperature changes.
2. The narrowband wavelock device for a laser as described in claim 1, characterized in that, The displacement compensation component includes a first connecting plate and a second connecting plate combined together. The composite direction of the first connecting plate and the second connecting plate is perpendicular to the light emission direction of the laser chip. The first connecting plate and the second connecting plate have different coefficients of thermal expansion. The first end of the displacement compensation component is rotatably connected to the base, and the second end is rotatably connected to the frequency doubling crystal holder.
3. The narrowband wavelock device for a laser and its fabrication process as described in claim 2, characterized in that, It also includes a piezoelectric ceramic actuator, which is disposed at the second end of the displacement compensation assembly and rotatably connected to the frequency doubling crystal holder.
4. A narrowband wavelock device for a laser as described in claim 3, characterized in that, The base includes a first thermally conductive layer and a second thermally conductive layer, and a semiconductor cooler is disposed between the first thermally conductive layer and the second thermally conductive layer.
5. A narrowband wavelock device for a laser as described in claim 4, characterized in that, The first thermally conductive layer is an aluminum nitride ceramic plate, and a heat spreader is integrated inside or on the bottom surface of the plate. The heat spreader is at least one of a graphene thermally conductive sheet, a heat spreader plate, or a sputtered copper thermally conductive channel, used to uniformly conduct the cooling energy generated by the semiconductor cooler.
6. A narrowband wavelock device for a laser as described in any one of claims 1-5, characterized in that, The laser chip's light-emitting surface is also provided with a narrow-band filter, and the base is also provided with a beam-shaping lens group, which includes a negative lens and a positive lens arranged sequentially along the light-emitting direction, for shaping the laser output through the frequency-doubling crystal.
7. A narrowband wavelock device for a laser as described in claim 6, characterized in that, The base is provided with a V-shaped track along the light emission direction, and the bottom of the frequency doubling crystal holder is provided with ball bearings adapted to the V-shaped track, and the ball bearings are slidably connected to the V-shaped track.
8. A fabrication process for a narrowband wavelock device for a laser, used to fabricate the narrowband wavelock device for a laser as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Base preparation: Select aluminum nitride ceramic material to process the first heat-conducting layer, and integrate a heat-equalizing layer inside or on the bottom surface of the first heat-conducting layer. The heat-equalizing layer adopts at least one of graphene heat-conducting sheet, heat-equalizing plate or sputtered copper heat-conducting channel, and is fixed by sputtering, bonding or embedded installation method. A second thermally conductive layer is made from a metal material with excellent thermal conductivity. The semiconductor cooler is then fixed between the first and second thermally conductive layers and bonded together with thermally conductive adhesive to ensure good thermal conductivity and form a complete base. A V-shaped track along the light-emitting direction is machined on the base, and the track surface is polished to reduce sliding friction; S2. Displacement compensation component preparation: Select two metal materials with different coefficients of thermal expansion, process them into a first connecting plate and a second connecting plate respectively, and combine them together by welding or bonding, with the composite direction perpendicular to the light output direction of the laser chip; Rotary connecting holes are processed at both ends of the displacement compensation component for connection with the base and the frequency doubling crystal holder. S3. Preparation of frequency doubling crystal clamp: The main body of the clamp is made of high temperature and high strength material. Ball bearings adapted to the V-shaped track are installed at the bottom of the clamp to ensure that the ball bearings can slide smoothly in the track. A clamping groove is machined inside the clamp to fix the frequency doubling crystal. An elastic buffer layer is set on the inner wall of the clamping groove to avoid damage to the frequency doubling crystal. S4. Component Assembly: Fix the laser chip to the first thermally conductive layer of the base using thermally conductive adhesive, ensuring that the light emission direction of the laser chip faces the preset light-transmitting window position; attach a narrow-band filter to the light emission surface of the laser chip, ensuring that the filter is tightly attached to the light emission surface without offset; rotatably connect the first end of the displacement compensation component to the base via a rotating shaft, and connect the second end to the piezoelectric ceramic driver, which is then rotatably connected to the frequency doubling crystal holder via a rotating shaft; fix the frequency doubling crystal in the clamping groove of the holder, and adjust the position of the holder so that the frequency doubling crystal is located in the optical path between the laser chip and the light-transmitting window; fix the beam shaping lens group on the base, so that the negative lens and the positive lens are arranged sequentially along the light emission direction, and the optical axis coincides with the light emission axis of the laser chip; S5. Housing Assembly: The assembled base is detachably connected to the housing using bolts. The light-transmitting window is installed, ensuring that it is aligned with the laser output direction and that the housing is well-sealed to prevent dust and moisture from entering. The entire device is debugged, and the temperature response performance of the displacement compensation component, the fine-tuning accuracy of the piezoelectric ceramic driver, the beam shaping effect, and the narrowband wave-locking performance are tested to ensure that the device meets the design requirements.