Laser resonant cavity and tunable laser device
By designing a laser resonant cavity including a total reflection collimator lens, a laser chip, a coupled lens, a filter assembly and a partial reflector in a coherent optical communication device, the problem of the length of the resonant cavity optical cavity is solved, and a narrower spectral line width and higher output optical power are achieved.
Patent Information
- Application Number
- CN202420494852.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-13
- Publication Date
- 2025-02-28
- Estimated Expiration
- 2034-03-13
AI Technical Summary
The resonant cavity optical cavity in existing coherent optical communication devices is short in length, making it difficult to achieve extremely narrow spectral line width.
A laser resonant cavity is designed, including a total reflection collimator lens, a laser chip, a coupling lens, a filter assembly and a partial reflector. Through the combination of these optical components, the optical cavity length of the resonant cavity is increased to achieve a narrower spectral line width.
By increasing the optical cavity length of the resonant cavity, a narrower spectral line width is achieved, meeting the coherent optical communication module's demand for high output optical power and adjustable wavelength.
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Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of optical communication, in particular to a laser resonant cavity and a tunable laser device. Background Art
[0002] In the coherent optical communication device industry, in the application scenarios of some coherent modules, a coherent laser device with high output optical power, arbitrarily switchable output working wavelength and narrow working spectrum linewidth is required as a light source; in existing coherent devices, the resonant cavity only contains a chip, which makes the optical cavity length of the resonant cavity relatively short. Generally speaking, the longer the optical cavity length of the resonant cavity, the narrower the spectral linewidth of the output resonant laser will be. Therefore, it is difficult for existing coherent devices to achieve extremely narrow spectral linewidth.
[0003] Therefore, it is very necessary for this field to design a laser resonant cavity and a tunable laser device that can just meet the application scenarios of the above-mentioned coherent optical communication module and can serve as a laser resonant cavity and a tunable laser device that meets the technical requirements. Utility Model Content
[0004] The technical problem to be solved by the embodiments of the utility model is to provide a laser resonant cavity and a tunable laser device to solve the problem that the optical cavity length of the resonant cavity in the prior art is relatively short and it is difficult to meet the demand for a narrow working spectrum line.
[0005] The utility model discloses a laser resonant cavity, which comprises: a total reflection collimating lens, a laser chip, a coupling lens, a filtering component and a partial reflecting mirror which are arranged in sequence, wherein the laser chip comprises a backward output waveguide port facing the total reflection collimating lens and a forward output waveguide port facing the coupling lens, wherein the backward output waveguide port is used to emit a first laser, the first laser is collimated by the total reflection collimating lens and reflected back into the laser chip, the forward output waveguide port is used to emit a second laser, the second laser and the first laser reflected back into the laser chip are emitted into the coupling lens together to form a collimated light beam, the collimated light beam is filtered by the filtering component and then emitted into the partial reflecting mirror, a part of the collimated light beam is reflected by the partial reflecting mirror and then returned in the reverse direction, and the other part is transmitted out through the partial reflecting mirror.
[0006] Optionally, the filter assembly includes three filters arranged in sequence along the light path direction, and the three filters are arranged in parallel.
[0007] Optionally, the filter assembly further comprises a base, the base is provided with a U-shaped groove, and the three filter sheets are all fixed in the U-shaped groove.
[0008] Optionally, the laser resonant cavity further comprises a chip carrier, and the laser chip is mounted on the chip carrier.
[0009] Optionally, a groove for mounting the total reflection collimating lens is provided on the chip carrier.
[0010] Optionally, the partial reflector is L-shaped, and a partial reflective film is coated on a side surface of the partial reflector facing the filter component.
[0011] In order to solve the problems existing in the prior art, the utility model also provides a tunable laser device, which comprises a housing and the laser resonant cavity as described above, wherein the laser resonant cavity is arranged in the housing.
[0012] Optionally, a refrigerator is further included, wherein the refrigerator is mounted inside the shell, and the laser resonant cavity is fixed on the refrigerator.
[0013] Optionally, the coupling lens is mounted on the refrigerator and is actively coupled to the refrigerator.
[0014] Optionally, a light window is provided on an end surface of the housing close to one end of the partial reflector.
[0015] Compared with the prior art, the beneficial effect of the laser resonant cavity provided by the embodiment of the utility model is that: by designing a laser resonant cavity, including a total reflection collimating lens, a laser chip, a coupling lens, a filter component and a partial reflection mirror arranged in sequence, the laser chip includes a backward output waveguide port toward the total reflection collimating lens and a forward output waveguide port toward the coupling lens; by incorporating all the optical components required in the tunable laser device into the resonant cavity, the optical cavity length of the resonant cavity is greatly increased, so that the corresponding tunable laser can have a narrower spectral linewidth. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The technical solution of the utility model will be further described in detail below with reference to the accompanying drawings and embodiments, in which:
[0017] Figure 1 This is a schematic diagram of the structure of the laser resonant cavity provided by the embodiment of the utility model. Figure 1 ;
[0018] Figure 2 It is a light path diagram of the laser resonant cavity provided by an embodiment of the utility model;
[0019] Figure 3 This is a schematic diagram of the structure of the laser resonant cavity provided by the embodiment of the utility model. Figure 2 ;
[0020] Figure 4This is a schematic diagram of the structure of the tunable laser device provided by the embodiment of the utility model. Figure 1 ;
[0021] Figure 5 The structure of the tunable laser device provided by the embodiment of the utility model is shown in FIG. Figure 2 .
[0022] The reference numerals in the figures are:
[0023] 1. Total reflection collimating lens; 2. Laser chip; 3. Coupling lens; 4. Filter assembly; 5. Partial reflector; 6. Chip carrier; 21. Backward output waveguide port; 22. Forward output waveguide port; 41. First filter; 42. Second filter; 43. Third filter; 44. Base; 61. Groove; 10. Shell; 20. Refrigerator; 101. Optical window. DETAILED DESCRIPTION
[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. Now, in conjunction with the accompanying drawings, a preferred embodiment of the present utility model is described in detail.
[0025] like Figures 1 to 3 As shown, the utility model provides a specific embodiment of a laser resonant cavity.
[0026] A laser resonant cavity, reference Figure 1 The laser resonant cavity includes a total reflection collimating lens 1, a laser chip 2, a coupling lens 3, a filter component 4 and a partial reflection mirror 5 which are arranged in sequence. The laser chip 2 includes a backward output waveguide port 21 toward the total reflection collimating lens 1 and a forward output waveguide port 22 toward the coupling lens 3.
[0027] Among them, reference Figure 1 and Figure 2 The backward output waveguide port 21 is used to emit the first laser, which is collimated by the total reflection collimating lens 1 and reflected back into the laser chip 2. The forward output waveguide port 22 is used to emit the second laser, which is emitted into the coupling lens 3 together with the first laser reflected back into the laser chip 2 to form a collimated light beam. The collimated light beam is filtered by the filter component 4 and then emitted into the partial reflector 5. A part of the collimated light beam is reflected by the partial reflector 5 and then returns in the opposite direction, and the other part is transmitted out through the partial reflector 5.
[0028] Specifically, refer to Figure 1 and Figure 2The laser chip 2 is mainly a microchip with an integrated laser structure for generating laser. The laser chip 2 contains a laser medium, which is a key part for generating laser and is usually a semiconductor material. Laser can be generated by exciting electron transitions in the laser medium. The laser chip 2 also contains a pump source for exciting the laser medium, such as current injection or optical pumping. The laser chip 2 also contains a laser waveguide, which is mainly used to guide the laser light to propagate inside the chip to ensure the stability and output quality of the laser. In this embodiment, a backward output waveguide port 21 and a forward output waveguide port 22 are respectively provided at both ends of the laser chip 2, and the backward output waveguide port 21 and the forward output waveguide port 22 are respectively used to emit the first laser and the second laser.
[0029] Further, refer to Figure 1 and Figure 2 The total emission collimating lens is arranged on one side of the laser chip 2 close to the backward output waveguide port 21. When the laser chip 2 outputs the first laser through its backward output waveguide port 21, the total reflection collimating lens 1 receives the first laser and is totally reflected back to the laser chip 2 after being collimated by the first laser.
[0030] Further, refer to Figure 1 and Figure 2 The coupling lens 3 is arranged on a side of the laser chip 2 close to the forward output waveguide port 22. The second laser outputted through the forward output waveguide port 22 of the laser chip 2 and the first laser totally reflected into the laser chip 2 by the total reflection collimating lens 1 and re-emitted from the forward output waveguide port 22 of the laser chip 2 are emitted into the coupling lens 3 together. The coupling lens 3 can couple the incident first laser and second laser into a collimated beam.
[0031] Further, refer to Figure 1 and Figure 2 The filter component 4 is arranged on the side of the coupling lens 3 away from the laser chip 2. When the collimated light beam coupled by the coupling lens 3 enters the filter component 4, the filter component 4 can filter it. Since the resonant laser emitted by the laser chip 2 is a multi-mode laser, it can be converted into a single-mode laser, that is, a laser with a single wavelength, after passing through the filter component 4. The wavelength converted by the filter component 4 is different under different working temperature environments. Therefore, by controlling the working temperature of the filter component 4, different wavelength selections can be achieved.
[0032] Further, refer to Figure 1 and Figure 2The partial reflector 5 is arranged on the side of the filter component 4 away from the coupling lens 3. After the filter component 4 filters the collimated light beam into a single-mode laser, the single-mode laser will be incident on the partial reflector 5. The partial reflector 5 can reflect a part of the single-mode collimated light beam back to the laser chip 2 along the reverse path, and transmit the other part of the remaining single-mode collimated light beam. The reflection ratio of the partial reflector 5 can be any value between 0% and 100%, that is, it can reflect 50% of the light beam and transmit 50% of the light beam, or it can reflect 2% of the light beam and transmit 98% of the light beam, etc.
[0033] Since some of the light beams are reflected by the partial reflector 5, this part of the light beam will return along the original path and return to the inside of the laser chip 2. These light beams reflected back to the inside of the laser chip 2 can further excite the laser chip 2 to generate greater laser energy. This is repeated. After countless times of excitation, the laser in the resonant cavity will become stronger and stronger.
[0034] In the above scheme, by incorporating the total reflection collimating lens, coupling lens, filter assembly and partial reflection mirror into the resonant cavity together with the laser chip, the optical cavity length of the resonant cavity is greatly increased, making the spectral line width of the resonant cavity narrower to meet current needs.
[0035] In one embodiment, reference Figure 3 The filter assembly 4 includes three filters arranged in sequence along the light path direction, and the three filters are arranged in parallel.
[0036] Specifically, refer to Figure 3 The filter assembly 4 includes a first filter 41, a second filter 42 and a third filter 43. The first filter 41, the second filter 42 and the third filter 43 are arranged in sequence along the light path direction, and the central axes of the first filter 41, the second filter 42 and the third filter 43 overlap to achieve a better filtering effect.
[0037] Further, refer to Figure 3 The filter assembly 4 also includes a base 44, which is mainly used to fix the first filter 41, the second filter 42 and the third filter 43. The top surface of the base 44 is provided with a U-shaped groove, which can be set as a single U-shaped groove, and the first filter 41, the second filter 42 and the third filter 43 are bonded in parallel in the U-shaped groove in sequence, or it can be set as a plurality of U-shaped grooves, each U-shaped groove corresponds to a filter, and the first filter 41, the second filter 42 and the third filter 43 are bonded in different U-shaped grooves respectively.
[0038] The specific spacing between the first filter 41 , the second filter 42 and the third filter 43 can be set and adjusted according to actual conditions.
[0039] In one embodiment, reference Figure 3 The laser resonant cavity further includes a chip carrier 6 , and the laser chip 2 is mounted on the chip carrier 6 .
[0040] Specifically, refer to Figure 3 The chip carrier 6 is mainly used for bonding the laser chip 2. The laser chip 2 is mounted on one side of the top surface of the chip carrier 6. The other side of the top surface of the chip carrier 6 is concave to form a groove 61 for mounting the total reflection collimating lens 1.
[0041] By concavely forming a groove 61 on one side of the chip carrier 6 , the mounting position of the total reflection collimating lens 1 can be made more accurate, and the mounting process can be made simpler.
[0042] In one embodiment, reference Figure 3 The partial reflector 5 is L-shaped, and a partial reflective film is plated on one side of the partial reflector 5 facing the filter component 4.
[0043] Specifically, refer to Figure 3 By setting the partial reflector 5 to be L-shaped, the plane position of the bottom of the partial reflector 5 is larger, and it can be bonded and installed more smoothly; wherein, a partial reflective film is coated on one side of the partial reflector 5 facing the filter component 4, while the bottom of the partial reflector 5 is not coated.
[0044] like Figure 3 , Figure 4 and Figure 5 As shown, the utility model also provides a specific embodiment of a tunable laser device.
[0045] A tunable laser device, reference Figure 3 and Figure 4 The tunable laser device includes a housing 10 and the laser resonant cavity as described above, and the laser resonant cavity is arranged in the housing 10 .
[0046] Specifically, refer to Figure 3 and Figure 4 A housing cavity is formed inside the shell 10 for accommodating the laser resonant cavity. The bottom surface of the shell 10 is a flat surface. The laser resonant cavity is arranged on the bottom surface of the shell 10 to ensure the working stability and accuracy of the laser resonant cavity. Specifically, the shell 10 can be set to a rectangular shape.
[0047] In one embodiment, reference Figure 4 and Figure 5 The tunable laser device further includes a refrigerator 20 , which is mounted inside the housing 10 , and the laser resonant cavity is fixed on the refrigerator 20 .
[0048] Specifically, refer to Figure 4 and Figure 5Specifically, the cooler 20 may be a TEC cooler 20. The TEC cooler 20 applies current between two semiconductor materials with different conductivities to transfer heat from one side to the other side, thereby achieving a cooling effect. The TEC cooler 20 has a wide operating temperature range, and has the advantages of small size, no vibration, no noise, and fast response speed, which can meet the needs of tunable laser devices.
[0049] In this embodiment, reference Figure 4 and Figure 5 The laser chip 2 is mounted on a chip carrier 6. The function of the chip carrier 6 is to support the chip and conduct the heat of the chip to the refrigerator 20 below. That is, the refrigerator 20 can control the temperature of the laser chip 2 by controlling the temperature of the chip carrier 6, thereby dissipating the heat of the laser chip 2.
[0050] Among them, reference Figure 4 and Figure 5 The refrigerator 20 is mounted flatly on the bottom surface of the housing 10, the laser resonant cavity is mounted flatly on the upper surface of the refrigerator 20, and the coupling lens 3 in the laser resonant cavity and the refrigerator 20 are mounted using an active coupling process.
[0051] In one embodiment, reference Figure 4 and Figure 5 A light window 101 is disposed on an end surface of the housing 10 close to the partial reflector 5 , and the light beam transmitted through the partial reflector 5 can be emitted through the light window 101 of the housing 10 .
[0052] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present utility model rather than to limit it. For those skilled in the art, the technical solutions described in the above embodiments can be modified, or some of the technical features therein can be replaced by equivalents; and all these modifications and replacements should fall within the scope of protection of the claims attached to the present utility model.
Claims
1. A laser resonant cavity, characterized in that: include: A total reflection collimating lens, a laser chip, a coupling lens, a filtering component and a partial reflecting mirror are arranged in sequence, wherein the laser chip comprises a backward output waveguide port facing the total reflection collimating lens and a forward output waveguide port facing the coupling lens, wherein the backward output waveguide port is used to emit a first laser, the first laser is collimated by the total reflection collimating lens and reflected back into the laser chip, the forward output waveguide port is used to emit a second laser, the second laser and the first laser reflected back into the laser chip are emitted into the coupling lens together to form a collimated light beam, the collimated light beam is filtered by the filtering component and then emitted into the partial reflecting mirror, a part of the collimated light beam is reflected by the partial reflecting mirror and then returned in the reverse direction, and the other part is transmitted out through the partial reflecting mirror.
2. The laser resonant cavity according to claim 1, characterized in that: The filter assembly comprises three filter plates which are arranged in sequence along the light path direction, and the three filter plates are arranged in parallel.
3. The laser resonant cavity according to claim 2, characterized in that: The filter assembly also includes a base, a U-shaped groove is provided on the base, and the three filter sheets are all fixed in the U-shaped groove.
4. The laser resonant cavity according to claim 1, characterized in that: The laser resonant cavity further comprises a chip carrier, and the laser chip is mounted on the chip carrier.
5. The laser resonant cavity according to claim 4, characterized in that: The chip carrier is provided with a groove for mounting the total reflection collimating lens.
6. The laser resonant cavity according to claim 1, characterized in that: The partial reflector is L-shaped, and a partial reflective film is plated on a side surface of the partial reflector facing the filter component.
7. A tunable laser device, characterized in that: It comprises a shell and a laser resonant cavity as described in any one of claims 1 to 6, wherein the laser resonant cavity is arranged in the shell.
8. The tunable laser device according to claim 7, characterized in that: It also includes a refrigerator, which is mounted inside the shell and the laser resonant cavity is fixed on the refrigerator.
9. The tunable laser device according to claim 8, characterized in that: The coupling lens is mounted on the refrigerator and is actively coupled to the refrigerator.
10. The tunable laser device according to claim 7, characterized in that: A light window is arranged on an end surface of the housing close to one end of the partial reflector.