Wavelength-adjustable laser and tuning method and application thereof

Abstract

The invention relates to the technical field of semiconductor lasers, in particular to a wavelength-adjustable laser and a tuning method and application thereof, and the wavelength-adjustable laser comprises a semiconductor laser gain assembly. A first aspheric collimating lens, an etalon, a second aspheric collimating lens and a lithium niobate optical waveguide reflector assembly are sequentially arranged on the right side of the semiconductor laser gain assembly; wherein the semiconductor laser gain assembly comprises a first optical high-reflection film and a first optical antireflection film, and the first optical high-reflection film is plated on the end face, away from the first aspheric collimating lens, of the semiconductor laser gain assembly; the first optical antireflection film is plated on the end face, facing the first aspheric collimating lens, of the semiconductor laser gain assembly. The adjustable wavelength laser provided by the invention has the advantages that: 1, the response speed is high (picosecond level); 2, the wavelength adjusting range is large (more than 100nm); 3, no mechanical moving part exists, and the reliability is good; and 4, wide application.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor lasers, and specifically to a tunable wavelength laser and its tuning method and application. Background Art

[0002] Due to their high efficiency, compactness, and high reliability, semiconductor lasers have been widely used in fields such as optical communication, optical sensing, medical treatment, and industrial processing. However, traditional tunable wavelength lasers rely on external optical elements (such as tunable filters, wavelength selective switches, etc.) to achieve wavelength tuning, suffering from problems such as large volume, high cost, slow tuning speed, and poor stability. In recent years, with the development of optical waveguide technology and electro-optic materials, wavelength tuning using the electro-optic effect has become a research hotspot. However, existing technologies are difficult to balance between tuning accuracy and response speed and cannot meet the requirements of high-speed communication and real-time sensing. Summary of the Invention

[0003] The purpose of the present invention is to provide a tunable wavelength laser and its tuning method and application to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A tunable wavelength laser includes a semiconductor laser gain component. A first aspheric collimating lens, a Fabry-Perot etalon, a second aspheric collimating lens, and a lithium niobate optical waveguide mirror component are sequentially arranged on the right side of the semiconductor laser gain component; Among them, the semiconductor laser gain component includes a first optical high reflection film and a first optical antireflection film. The first optical high reflection film is plated on the end face of the semiconductor laser gain component away from the first aspheric collimating lens, and the first optical antireflection film is plated on the end face of the semiconductor laser gain component facing the first aspheric collimating lens; A lithium niobate thin film optical waveguide is arranged on the upper end face of the lithium niobate optical waveguide mirror component. Metal electrodes + and metal electrodes - are respectively arranged on the left and right sides of the lithium niobate thin film optical waveguide. A second optical antireflection film is plated on the end face of the lithium niobate optical waveguide mirror component close to the second aspheric collimating lens, and a second optical high reflection film is plated on the end face of the lithium niobate optical waveguide mirror component away from the second aspheric collimating lens; A tuning method for a tunable wavelength laser is as follows: S1. Select a semiconductor laser gain chip with an emission wavelength range of 1530 nm - 1630 nm, and plate a first optical antireflection film on its incident end face and a first optical high reflection film on its reflection end face to obtain a semiconductor laser gain component; S2. Prepare a lithium niobate optical waveguide mirror device with a size of 2 cm × 0.5 cm × 0.1 cm by using micro-nano processing technology, coat a second optical antireflection film on its incident end face, and coat a second optical high-reflection film on its reflection end face to obtain a lithium niobate optical waveguide mirror assembly; S3. High-precision alignment and fixation of the semiconductor laser gain assembly, the first aspherical collimating lens, the etalon, the second aspherical collimating lens and the lithium niobate optical waveguide mirror assembly to form a laser resonator; S4. On the lithium niobate thin film optical waveguide, by adjusting the electric field strength and direction, use the electro-optic effect to change its effective refractive index and the change of the effective cavity length of the laser resonator cavity, and realize continuous tuning of the laser wavelength in the range of 1530 nm to 1630 nm.

[0005] As a further preferred embodiment of this technical solution, the reflectivity of the second optical antireflection film is R1, the reflectivity of the second optical high-reflection film is R2, and R2 >> R1.

[0006] As a further preferred embodiment of this technical solution, the end face of the lithium niobate thin film optical waveguide facing the etalon deviates from the optical axis by 1° - 2°.

[0007] The above tunable wavelength laser is applied in the fields of optical communication, optical sensing and medical treatment.

[0008] The present invention provides a tunable wavelength laser, which has the following beneficial effects: 1. High-precision tuning: By precisely controlling the changes of the effective refractive index and the effective cavity length of the resonator (refractive index × geometric cavity length), high-precision wavelength tuning is achieved, meeting the requirements for wavelength accuracy in fields such as optical communication and optical sensing; 2. Fast response: The electric field tuning unit has the characteristic of fast response and can complete the switching of the laser wavelength in a short time, being suitable for high-speed optical communication networks and real-time sensing systems; 3. High stability: The combination of optical coating technology and electro-optic effect reduces the optical reflection loss and improves the stability of the laser, enabling it to work reliably in complex environments; 4. Wide application: This laser can be applied in the fields of optical communication, optical sensing and medical treatment, providing strong support for the development of these fields.

[0009] In summary, the tunable wavelength laser provided by the present invention has the advantages of fast response speed (picosecond level), large wavelength tuning range (more than 100 nm), good reliability without mechanical moving parts and wide application. Description of the Drawings

[0010] Figure 1 It is the top view of the tunable wavelength laser in the present invention; Figure 2This is the front view of the tunable wavelength laser in the present invention.

[0011] In the figure: 1. Semiconductor laser gain component; 11. First optical high reflection film; 12. First optical antireflection film; 2. First aspherical collimating lens; 3. Etalon; 4. Second aspherical collimating lens; 5. Lithium niobate optical waveguide mirror assembly; 51. Second optical high reflection film; 52. Lithium niobate thin film optical waveguide; 53. Metal electrode +; 54. Metal electrode -; 55. Second optical antireflection film. Specific embodiments

[0012] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0013] Embodiment 1 As Figure 1 and Figure 2 shown, in this embodiment, a tunable wavelength laser includes a semiconductor laser gain component 1. The first aspherical collimating lens 2, the etalon 3, the second aspherical collimating lens 4, and the lithium niobate optical waveguide mirror assembly 5 are sequentially arranged on the right side of the semiconductor laser gain component 1; Among them, the semiconductor laser gain component 1 includes a first optical high reflection film 11 and a first optical antireflection film 12. The first optical high reflection film 11 is plated on the end face of the semiconductor laser gain component 1 away from the first aspherical collimating lens 2, and the first optical antireflection film 12 is plated on the end face of the semiconductor laser gain component 1 facing the first aspherical collimating lens 2; it is used to provide laser gain and can emit laser within a certain wavelength range. Among them, a high reflectivity R1 optical film is plated on the end face of the laser gain facing the light output end face to form the mirror M1 at the light output end of the laser resonator cavity, and an antireflection AR optical film is plated on the end face of the laser gain facing the etalon direction to reduce the interface light reflection loss; The upper end face of the lithium niobate optical waveguide mirror assembly 5 is provided with a lithium niobate thin film optical waveguide 52. The left and right sides of the lithium niobate thin film optical waveguide 52 are respectively provided with a metal electrode + 53 and a metal electrode - 54. The end face of the lithium niobate optical waveguide mirror assembly 5 close to the second aspherical collimating lens 4 is plated with a second optical antireflection film 55, and the end face of the lithium niobate optical waveguide mirror assembly 5 away from the second aspherical collimating lens 4 is plated with a second optical high reflection film 51.

[0014] A tuning method for a tunable wavelength laser is as follows: S1. Select a semiconductor laser gain chip with an emission wavelength range of 1530 nm - 1630 nm, and plate the first optical antireflection film 12 on its incident end face and the first optical high reflection film 11 on its reflection end face to obtain the semiconductor laser gain component 1; S2. Prepare a lithium niobate optical waveguide mirror device with dimensions of 2 cm × 0.5 cm × 0.1 cm using micro-nano processing technology. Coat a second optical antireflection film 55 on its incident end face and a second optical high-reflection film 51 on its reflection end face to obtain a lithium niobate optical waveguide mirror assembly 5; S3. Align and fix the semiconductor laser gain assembly 1, the first aspherical collimating lens 2, the etalon 3, the second aspherical collimating lens 4, and the lithium niobate optical waveguide mirror assembly 5 with high precision to form a laser resonator; S4. On the lithium niobate thin film optical waveguide 52, by adjusting the electric field strength and direction, use the electro-optic effect to change its effective refractive index and the effective cavity length of the resonator (refractive index × geometric cavity length) to achieve continuous tuning of the laser wavelength in the range of 1530 nm to 1630 nm.

[0015] Applications of the tunable wavelength laser in the fields of optical communication, optical sensing, and medical treatment.

[0016] Embodiment 2 As Figure 1 and Figure 2 shown, in this embodiment, a tunable wavelength laser includes a semiconductor laser gain assembly 1. The first aspherical collimating lens 2, the etalon 3, the second aspherical collimating lens 4, and the lithium niobate optical waveguide mirror assembly 5 are sequentially arranged on the right side of the semiconductor laser gain assembly 1; Among them, the semiconductor laser gain assembly 1 includes a first optical high-reflection film 11 and a first optical antireflection film 12. The first optical high-reflection film 11 is coated on the end face of the semiconductor laser gain assembly 1 away from the first aspherical collimating lens 2, and the first optical antireflection film 12 is coated on the end face of the semiconductor laser gain assembly 1 facing the first aspherical collimating lens 2; The upper end face of the lithium niobate optical waveguide mirror assembly 5 is provided with a lithium niobate thin film optical waveguide 52. A metal electrode +53 and a metal electrode -54 are respectively arranged on the left and right sides of the lithium niobate thin film optical waveguide 52. A second optical antireflection film 55 is coated on the end face of the lithium niobate optical waveguide mirror assembly 5 close to the second aspherical collimating lens 4, and a second optical high-reflection film 51 is coated on the end face of the lithium niobate optical waveguide mirror assembly 5 away from the second aspherical collimating lens 4; Further, the reflectivity of the second optical antireflection film 55 is R1, and the reflectivity of the second optical high-reflection film 51 is R2, where R2 >> R1. As a mirror assembly, replacing the two-dimensional planar mirror at one end of a traditional laser, the end facing the laser gain chip is coated with an antireflection AR optical film to reduce the loss of interface light reflection, and the end facing away from the gain chip is coated with a high-reflectivity R2 optical film to form the mirror M2 at the optical output end of the laser resonator cavity. The reflectivity R2 > R1 to ensure that the laser mainly outputs from the end face of M1; to reduce the noise caused by end face reflection stray light.

[0017] A tuning method for a tunable wavelength laser is as follows: S1. Select a semiconductor laser gain chip with an emission wavelength range of 1530 nm - 1630 nm, coat a first optical antireflection film 12 on its incident end face, and coat a first optical high-reflection film 11 on its reflection end face to obtain a semiconductor laser gain assembly 1. S2. Use micro-nano processing technology to prepare a lithium niobate optical waveguide mirror device with dimensions of 2 cm × 0.5 cm × 0.1 cm, coat a second optical antireflection film 55 on its incident end face, and coat a second optical high-reflection film 51 on its reflection end face to obtain a lithium niobate optical waveguide mirror assembly 5. S3. High-precision alignment and fixation of the semiconductor laser gain assembly 1, the first aspherical collimating lens 2, the etalon 3, the second aspherical collimating lens 4, and the lithium niobate optical waveguide mirror assembly 5 to form a laser resonator cavity. S4. By adjusting the electric field strength and direction on the lithium niobate thin film optical waveguide 52, use the electro-optic effect to change its effective refractive index and the effective cavity length of the resonator cavity (refractive index × geometric cavity length) to achieve continuous tuning of the laser wavelength in the range of 1530 nm to 1630 nm.

[0018] The application of the tunable wavelength laser in the fields of optical communication, optical sensing, and medical treatment.

[0019] Embodiment 3 As Figure 1 and Figure 2 shown, in this embodiment, a tunable wavelength laser includes a semiconductor laser gain assembly 1, and a first aspherical collimating lens 2, an etalon 3, a second aspherical collimating lens 4, and a lithium niobate optical waveguide mirror assembly 5 are sequentially arranged on the right side of the semiconductor laser gain assembly 1; Among them, the semiconductor laser gain assembly 1 includes a first optical high-reflection film 11 and a first optical antireflection film 12. The first optical high-reflection film 11 is coated on the end face of the semiconductor laser gain assembly 1 away from the first aspherical collimating lens 2, and the first optical antireflection film 12 is coated on the end face of the semiconductor laser gain assembly 1 facing the first aspherical collimating lens 2; The upper end face of the lithium niobate optical waveguide mirror assembly 5 is provided with a lithium niobate thin film optical waveguide 52. Metal electrodes +53 and metal electrodes -54 are respectively arranged on the left and right sides of the lithium niobate thin film optical waveguide 52. The end face of the lithium niobate optical waveguide mirror assembly 5 close to the second aspherical collimating lens 4 is coated with a second optical antireflection film 55, and the end face of the lithium niobate optical waveguide mirror assembly 5 far from the second aspherical collimating lens 4 is coated with a second optical high reflection film 51; Further, the reflectivity of the second optical antireflection film 55 is R1, and the reflectivity of the second optical high reflection film 51 is R2, R2 >> R1; As a mirror assembly, replacing the two-dimensional plane mirror at one end of the traditional laser, one end facing the laser gain chip is the light incident end face coated with an antireflection AR optical film to reduce the interface light reflection loss, and the end face facing away from the gain chip is coated with a high reflectivity R2 optical film to form the mirror M2 at the light output end of the laser resonant cavity. The reflectivity R2 > R1 to ensure that the laser mainly outputs from the end face of M1; In order to reduce the noise caused by the end face reflected stray light.

[0020] Further, the end face of the lithium niobate thin film optical waveguide 52 facing the etalon 3 deviates from the optical axis by 1° - 2°; The lithium niobate thin film optical waveguide 52 can avoid the end face reflected light by rotating a small angle.

[0021] A tuning method for a tunable wavelength laser is as follows: S1. Select a semiconductor laser gain chip with an emission wavelength range of 1530 nm - 1630 nm, coat a first optical antireflection film 12 on its incident end face, and coat a first optical high reflection film 11 on its reflection end face to obtain a semiconductor laser gain assembly 1; S2. Use micro-nano processing technology to prepare a lithium niobate optical waveguide mirror device with a size of 2 cm × 0.5 cm × 0.1 cm, coat a second optical antireflection film 55 on its incident end face, and coat a second optical high reflection film 51 on its reflection end face to obtain a lithium niobate optical waveguide mirror assembly 5; S3. The semiconductor laser gain assembly 1, the first aspherical collimating lens 2, the etalon 3, the second aspherical collimating lens 4 and the lithium niobate optical waveguide mirror assembly 5 are accurately aligned and fixed to form a laser resonant cavity; S4. By adjusting the electric field intensity and direction on the lithium niobate thin film optical waveguide 52, use the electro-optic effect to change its effective refractive index and the effective cavity length of the resonant cavity (refractive index × geometric cavity length) to realize continuous tuning of the laser wavelength in the range of 1530 nm to 1630 nm.

[0022] Applications of the tunable wavelength laser in the fields of optical communication, optical sensing and medical treatment.

[0023] Analyze the influence of the effective refractive index change on wavelength tuning 1. Case of increasing effective refractive index: Assume the effective refractive index increases from n eff1 = 2.2 to n eff2 = 2.3. According to the formula λb = 2n eff Λ, the wavelength before change λ b1 = 2×2.2×352.27 = 1550 nm; the wavelength after change λ b2 = 2×2.3×352.27 ≈ 1616.44 nm. This shows that when the effective refractive index increases, the wavelength increases, and the increase amplitude is Δλ = λ b2 −λ b1 = 1616.44 − 1550 = 66.44 nm; 2. Case of decreasing effective refractive index: Assume the effective refractive index decreases from n eff1 = 2.2 to n eff3 = 2.1. The wavelength before change λ b1 = 2×2.2×352.27 = 1550 nm; the wavelength after change λ b3 = 2×2.1×352.27 ≈ 1479.53 nm. This shows that when the effective refractive index decreases, the wavelength decreases, and the decrease amplitude is Δλ = λ b1 −λ b3 = 1550 − 1479.53 = 70.47 nm; 3. Comprehensive influence in practical applications: In actual lithium niobate photonic devices, the effective refractive index change range is 0.01 - 0.1. Taking the increase of the effective refractive index by 0.01 as an example, from n eff = 2.2 to n eff = 2.21. The wavelength before change λ b1 = 2×2.2×352.27 = 1550 nm, the wavelength after change λ b4 = 2×2.21×352.27 ≈ 1557.05 nm, and the wavelength change amount Δλ = λ b4 −λ b1 = 1557.05 − 1550 = 7.05 nm. It can be seen that even a small change in the effective refractive index will cause a significant change in the wavelength. In application scenarios such as optical communication and optical sensing with high requirements for wavelength accuracy, this change needs to be precisely controlled and considered.

[0024] Performance tests were carried out on this laser, and the results show that its tuning speed reaches within 100 ms, the wavelength accuracy is better than 0.1 nm, and in the case of continuous operation for 10 hours, the wavelength fluctuation range is less than 0.05 nm, indicating good stability.

[0025] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An adjustable wavelength laser, comprising a semiconductor laser gain component (1), characterized in that: On the right side of the semiconductor laser gain component (1), a first aspheric collimating lens (2), a etalon (3), a second aspheric collimating lens (4), and a lithium niobate optical waveguide mirror component (5) are sequentially arranged; Among them, the semiconductor laser gain component (1) includes a first optical high-reflection film (11) and a first optical antireflection film (12). The first optical high-reflection film (11) is plated on the end face of the semiconductor laser gain component (1) far from the first aspheric collimating lens (2), and the first optical antireflection film (12) is plated on the end face of the semiconductor laser gain component (1) facing the first aspheric collimating lens (2); On the upper end face of the lithium niobate optical waveguide mirror component (5), a lithium niobate thin film optical waveguide (52) is provided. On the left and right sides of the lithium niobate thin film optical waveguide (52), a metal electrode + (53) and a metal electrode - (54) are respectively provided. On the end face of the lithium niobate optical waveguide mirror component (5) close to the second aspheric collimating lens (4), a second optical antireflection film (55) is plated, and on the end face of the lithium niobate optical waveguide mirror component (5) far from the second aspheric collimating lens (4), a second optical high-reflection film (51) is plated.

2. The tunable wavelength laser according to claim 1, wherein: The reflectivity of the second optical antireflection film (55) is R1, R1 < 0.03%, and the reflectivity of the second optical high-reflection film (51) is R2, R2 = 99.9%.

3. An adjustable wavelength laser according to claim 1, characterized in that: The end face of the lithium niobate thin film optical waveguide (52) facing the etalon (3) is deviated from the optical axis by 1° - 2°.

4. A tuning method for an adjustable wavelength laser according to claims 1-3, characterized in that, The specific steps are as follows: S1. Select a semiconductor laser gain chip with an emission wavelength range of 1530 nm - 1630 nm, and plate a first optical antireflection film (12) on its incident end face and a first optical high-reflection film (11) on its reflection end face to obtain the semiconductor laser gain component (1); S2. Use micro-nano processing technology to prepare a lithium niobate optical waveguide mirror device with a size of 2 cm × 0.5 cm × 0.1 cm, and plate a second optical antireflection film (55) on its incident end face and a second optical high-reflection film (51) on its reflection end face to obtain the lithium niobate optical waveguide mirror component (5); S3. The semiconductor laser gain component (1), the first aspheric collimating lens (2), the etalon (3), the second aspheric collimating lens (4), and the lithium niobate optical waveguide mirror component (5) are accurately aligned and fixed to form a laser resonator; S4. On the lithium niobate thin film optical waveguide (52), by adjusting the electric field strength and direction, use the electro-optic effect to change its effective refractive index and the effective cavity length of the resonator (refractive index × geometric cavity length) to achieve continuous tuning of the laser wavelength in the range of 1530 nm to 1630 nm.

5. An application of the tunable wavelength laser according to claims 1 - 3 in the fields of optical communication, optical sensing, and medical treatment.

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