Device and method for generating short-wavelength random laser
By designing an oscillation cavity containing a short-wavelength highly reflective grating, a double-clad active fiber, a tilted grating and a passive fiber, the problem of difficulty in generating short-wavelength random lasers in the existing technology is solved, and a stable output of short-wavelength random lasers is achieved. Effect.
Patent Information
- Application Number
- CN202411373387.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2025-01-24
AI Technical Summary
It is difficult for the prior art to generate short-wavelength random lasers. The existing random lasers are mainly long-wavelength and cannot develop towards short-waves.
Designed a device including laser unit and the oscillating cavity. The shock cavity consists of a short -wave height high -anti -light grid, a dual -pack -like -like optical fiber, an inclined grating and passive fiber. Internal wavelength selection and vertical model selection to generate short -wavelength random laser.
The ability to generate short -wave length random laser is realized. Through the clever shocking cavity design and the setting of the inclined grating, the short -wavelength random laser is stably output, which solves the problem of random laser wavelength in existing technologies.
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Figure CN119362122A_ABST
Abstract
Description
Technical Field
[0002] The present invention relates to the technical field of optical fiber lasers, and in particular to a device and method for generating short-wavelength random lasers. Background Art
[0004] At present, the random lasers generated by existing technologies are mainly long wavelengths. The principle is to use conventional lasers as pump lasers to stimulate the Raman effect in longer passive optical fibers to generate Raman random lasers. For example, conventional lasers with a wavelength of 1040-1080nm are generated by using fiber gratings plus ytterbium-doped optical fibers, and the wavelength of the Raman random lasers generated based on this wavelength is generally in the range of 1090-1134nm (for example, in silicon-based optical fibers, the wavelength of the Raman random laser is obtained by frequency shifting the pump laser wavelength by 13.2THz), and it develops towards longer wavelengths. Therefore, the random laser wavelengths of existing schemes of this type are relatively long and cannot be developed towards shorter wavelengths.
[0005] On the other hand, in the direction of short-wavelength lasers, only conventional short-wavelength fiber lasers have been reported so far, and there is little research on short-wavelength random lasers. Summary of the invention
[0007] To this end, the main purpose of the present invention is to provide a device and method for generating short-wavelength random laser to generate short-wavelength random laser.
[0008] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided a device for generating short-wavelength random laser, which comprises: a laser unit, an oscillating cavity, wherein the oscillating cavity comprises: a short-wavelength high-reflection grating, a double-clad active optical fiber, a tilted grating, and a passive optical fiber connected in sequence, wherein the laser unit is connected to the oscillating cavity, outputs laser to it, and after being gained by the double-clad active optical fiber to become a wide-band laser, inputs the tilted grating to consume the laser at the long-wave position of the wide-band laser, so that the short-wavelength laser enters the passive optical fiber for Rayleigh scattering, so as to form a round-trip oscillation with the short-wavelength high-reflection grating, and generate short-wavelength random laser.
[0009] In a possible preferred embodiment, the laser unit includes: a semiconductor laser and a beam combiner. The semiconductor laser is connected to the input end of the short-wavelength high-reflection grating through the beam combiner to access the oscillation cavity, coupled into the double-clad active optical fiber, and forward pumped so that the short-wavelength random laser is output from the output end of the passive optical fiber.
[0010] In a possible preferred embodiment, the laser unit includes: a semiconductor laser and a beam combiner. The semiconductor laser is connected to the output end of the passive optical fiber through the beam combiner to access the oscillation cavity, and is reversely coupled into the double-clad active optical fiber through the tilted grating and the passive optical fiber for reverse pumping, so that short-wavelength random laser is output from the output end of the beam combiner.
[0011] In a possible preferred embodiment, the laser unit includes: a semiconductor laser and a beam combiner. The semiconductor laser is connected to the output end of the double-clad active optical fiber through the beam combiner to access the oscillator cavity for reverse pumping, so that short-wavelength random laser is output from the output end of the passive optical fiber.
[0012] In a possible preferred embodiment, the wavelength of the short-wavelength high-reflection grating is located in the short-wavelength range within the emission band of the double-clad active optical fiber, and the reflectivity of the short-wavelength high-reflection grating is >99%.
[0013] In a possible preferred embodiment, the double-clad active optical fiber is any one of: ytterbium-doped optical fiber, erbium-doped optical fiber, and thulium-doped optical fiber.
[0014] In a possible preferred embodiment, the tilted grating wavelength is set at the maximum position of the double-clad active optical fiber emission cross-sectional parameter, and the tilt angle of the tilted grating is 45°.
[0015] In a possible preferred embodiment, the output end of the passive optical fiber is inclined at an angle of 8°.
[0016] In a possible preferred embodiment, the tilted grating is inscribed on either a double-clad active optical fiber or a passive optical fiber.
[0017] In order to achieve the above object, corresponding to the above device, according to another aspect of the present invention, a method for generating short-wavelength random laser is provided, the steps of which include:
[0018] The operating wavelength of the semiconductor laser is set to be within the absorption band of the double-clad active optical fiber; the wavelength of the short-wavelength high-reflection grating is set to be within the short-wavelength range of the emission band of the double-clad active optical fiber;
[0019] Setting the tilted grating wavelength to be located at the maximum position of the emission cross-sectional parameter of the double-clad active optical fiber;
[0020] The semiconductor laser is started to output laser, which is then gained into a wide-band laser through a double-clad active optical fiber. Then, the laser at the long-wave position of the wide-band laser is lost through a tilted grating, so that the short-wavelength laser enters the passive optical fiber for Rayleigh scattering and forms a reciprocating oscillation with a short-wavelength high-reflection grating to perform wavelength selection and longitudinal mode selection, and then output a short-wavelength random laser.
[0021] By means of the device and method for generating short-wavelength random laser provided by the present invention, the oscillation cavity structure is cleverly designed, so that the laser is converted into short-wavelength laser in the oscillation cavity, and Rayleigh scattering is performed in the passive optical fiber to obtain feedback, and a back-and-forth oscillation is formed with the short-wavelength high-reflection grating to perform wavelength selection and longitudinal mode selection to form short-wavelength random laser. In addition, in the corresponding embodiment, by setting the wavelength and the tilt angle of the tilted grating, not only the laser at the long-wavelength position of the wide-band laser can be lost to obtain short-wavelength laser, but also the amplified spontaneous radiation can be filtered out and the output power can be stabilized. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:
[0024] Figure 1 A schematic diagram of a forward pumping structure of a device for generating short-wavelength random laser of the present invention;
[0025] Figure 2 FIG. 1 is a schematic diagram of a reverse pumping structure of a first example of a device for generating short-wavelength random laser of the present invention;
[0026] Figure 3 FIG. 1 is a schematic diagram of a reverse pumping structure of a second example of the apparatus for generating short-wavelength random laser of the present invention;
[0027] Figure 4 It is a schematic diagram of the steps of the method for generating short-wavelength random laser of the present invention.
[0028] Description of Reference Numerals
[0029] Semiconductor laser 1, beam combiner 2, short-wavelength high-reflection grating 3, double-clad active optical fiber 4, tilted grating 5, passive optical fiber 6, passive optical fiber output end 602, pump fiber 202, beam combiner input end 201, beam combiner output end 201'. DETAILED DESCRIPTION
[0031] In order to enable those skilled in the art to better understand the technical solution of the present invention, the specific technical solution of the present invention will be clearly and completely described in conjunction with the embodiments below to help those skilled in the art further understand the present invention. Obviously, the embodiments described in this case are only embodiments of a part of the present invention, not all of the embodiments. It should be pointed out that for those of ordinary skill in the art, the embodiments in this application and the features in the embodiments can be combined with each other without departing from the concept of the present invention and without conflicting with each other. Based on the embodiments in the present invention, all other embodiments obtained without creative work by those of ordinary skill in the art should belong to the disclosure and protection scope of the present invention.
[0032] In addition, the terms "first", "second", "S100", "S200", etc. in the specification, claims and drawings of the present invention are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the features used in this way can be interchanged where appropriate, so that the embodiments of the present invention described here can be implemented in an order other than those described here. At the same time, the stages recorded in each step are not mandatory to be implemented in the same step. It should be understood that the implementation order of the contents in each step stage can be adjusted and interchanged without violating the inventive concept, so that the step embodiments of the present invention described here can be implemented in an order other than those described here. In addition, the terms "including" and "having" and any of their variations in the present invention are intended to cover non-exclusive inclusions. Unless otherwise clearly specified and limited, the terms "set", "layout", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this case can be understood according to specific circumstances and in combination with the prior art.
[0033] To generate short wavelength random lasers, see Figures 1 to 3 As shown, the present invention provides a device for generating short-wavelength random laser, which includes: a laser unit, an oscillating cavity, wherein the oscillating cavity includes: a short-wavelength high-reflection grating 3, a double-clad active optical fiber 4, a tilted grating 5, and a passive optical fiber 6 connected in sequence; the laser unit includes: a semiconductor laser 1 and a beam combiner 2. The operating wavelength of the semiconductor laser 1 needs to be set within the absorption band of the double-clad active optical fiber 4; and the wavelength of the short-wavelength high-reflection grating 3 needs to be set within the short-wave range within the emission band of the double-clad active optical fiber 4, and the reflectivity of the short-wavelength high-reflection grating 3 is preferably greater than 99%.
[0034] Among them, Figure 1 As shown, an example of a forward pumping implementation is given. In this example, the semiconductor laser 1 is connected to the combiner 2 via the pump fiber 202, and is connected to the input end of the short-wavelength high-reflection grating 3 through the combiner 2 to couple into the double-clad active optical fiber 4 for forward pumping, and after obtaining the short-wavelength random laser, it is output from the passive optical fiber output end 602.
[0035] Specifically, the laser light (e.g., 900-980 nm) emitted by the semiconductor laser 1 passes through the beam combiner 2, and after passing through the short-wavelength high-reflection grating 3, it will be injected into the double-clad active optical fiber 4 and absorbed. Since the gain ions in the double-clad active optical fiber 4 are in an excited state, they will spontaneously radiate to generate wide-band laser light (e.g., 1010-1060 nm).
[0036] At this time, when the wide-band laser passes through the tilted grating 5, the laser at the long-wave position of the wide-band laser will be lost by the tilted grating 5, and due to the existence of the tilted grating 5, the long-wavelength laser in the double-clad active optical fiber 4 will be converted into a cladding mode and cannot be transmitted in the core. The short-wavelength laser can be further transmitted into the passive optical fiber 6, and through Rayleigh scattering in the passive optical fiber 6, randomness is formed, and some light particles are opposite to the direction of the incident light, forming backward transmission light, that is, reflected light. The existence of this reflected light makes the optical signal in the optical fiber not only propagate forward, but also have a reverse propagation component, thereby forming a round-trip oscillation phenomenon between the passive optical fiber 6 and the short-wavelength high-reflection grating 3 to perform wavelength (frequency) selection and longitudinal mode selection, and finally form a short-wavelength random laser and output it from the passive optical fiber output end 602.
[0037] It is worth mentioning that, since the emission cross-sectional parameters of the active optical fiber are expressed as absorption and emission probabilities of different wavelengths, in this example, it is preferred to set the tilt angle of the tilted grating 5 to 45°, and set the wavelength of the tilted grating 5 to the maximum position of the emission cross-sectional area of the double-clad active optical fiber 4, that is, the wavelength position where the active optical fiber is most likely to generate lasers, and the wavelength position where the laser is most likely to be generated is also the position where the wavelength of amplified spontaneous radiation is most likely to be generated. Therefore, by setting the tilted optical fiber in the above manner, the amplified spontaneous radiation can be effectively filtered out to stabilize the output power.
[0038] Wherein, corresponding to the above example, in an optional implementation, the double-clad active optical fiber 4 can be selected as any one of: ytterbium-doped optical fiber, erbium-doped optical fiber, and thulium-doped optical fiber. Wherein, when ytterbium-doped optical fiber is selected, the wavelength of the short-wavelength high-reflection grating 3 is preferably less than 1030nm and greater than 1000nm; when erbium-doped optical fiber is selected, the wavelength of the short-wavelength high-reflection grating 3 is preferably less than 1530nm and greater than 1500nm; when thulium-doped optical fiber is selected, the wavelength of the short-wavelength high-reflection grating 3 is preferably less than 1900nm and greater than 1600nm. At the same time, it is preferred to set the central wavelength of the tilted grating 5 to 1035nm, the 20dB bandwidth to 20nm, and the loss of 1025-1045nm to 20dB.
[0039] Furthermore, in an optional embodiment, the passive optical fiber output end 602 is preferably arranged at an angle of 8°.
[0040] Furthermore, in an optional implementation, the tilted grating 5 can be engraved on the double-clad active optical fiber 4 or on the passive optical fiber 6. Those skilled in the art can choose to implement or combine the implementations according to actual conditions.
[0041] On the other hand, Figure 2 As shown, it is an implementation method of the first example of reverse pumping. In this example, the semiconductor laser 1 is connected to the output end of the passive optical fiber 6 through the beam combiner 2 to access the oscillation cavity, thereby reversely passing through the tilted grating 5 and the passive optical fiber 6, coupled into the double-clad active optical fiber 4, and reversely pumped, so that the laser output by the semiconductor laser 1 is converted into a wide-band laser after the double-clad active optical fiber 4 gains it, and then inputs the tilted grating 5 to lose the laser at the long-wave position of the wide-band laser, so that the short-wave laser enters the passive optical fiber 6 for Rayleigh scattering, so as to form a reciprocating oscillation with the short-wavelength high-reflection grating 3, and after generating a short-wavelength random laser, it is output from the output end 201' of the beam combiner. The specific working process of the oscillation cavity can refer to the above example, which will not be repeated here.
[0042] On the other hand, Figure 3 As shown, it is an implementation method of the second example of reverse pumping. In this example, the semiconductor laser 1 is connected to the output end of the double-clad active fiber 4 through the beam combiner 2 to access the oscillation cavity for reverse pumping, so that the laser output by the semiconductor laser 1 is converted into a wide-band laser after the gain of the double-clad active fiber 4, and then input into the tilted grating 5 to lose the laser at the long-wave position of the wide-band laser, so that the short-wave laser enters the passive fiber 6 for Rayleigh scattering, so as to form a round-trip oscillation with the short-wavelength high-reflection grating 3, and after generating a short-wavelength random laser, it is output from the passive fiber output end 602. The specific working process of the oscillation cavity can refer to the above example, which will not be repeated here.
[0043] On the other hand, Figure 4As shown, corresponding to the above device example, the present invention also provides a method for generating short-wavelength random laser, the steps of which include:
[0044] Step S100 sets the working wavelength of the semiconductor laser 1 to be within the absorption band of the double-clad active optical fiber 4 ; the wavelength of the short-wavelength high-reflection grating 3 to be within the short-wave range of the emission band of the double-clad active optical fiber 4 .
[0045] Step S200 sets the wavelength of the tilted grating 5 to be located at the maximum position of the emission cross section of the double-clad active optical fiber 4, and sets the tilt angle of the tilted grating 5 to 45°.
[0046] Step S300 starts the semiconductor laser 1 to output laser, and after the gain is obtained through the double-clad active optical fiber 4 as a wide-band laser, the laser at the long-wave position of the wide-band laser is lost through the inclined grating 5, so that the short-wavelength laser enters the passive optical fiber 6 for Rayleigh scattering, and forms a reciprocating oscillation with the short-wavelength high-reflection grating 3, so as to perform wavelength selection and longitudinal mode selection, and then output short-wavelength random laser.
[0047] In summary, the device and method for generating short-wavelength random laser provided by the present invention cleverly designs the oscillation cavity structure, so that the laser is converted into short-wavelength laser in the oscillation cavity, and Rayleigh scattering is performed in the passive optical fiber 6 to obtain feedback, and a back-and-forth oscillation is formed with the short-wavelength high-reflection grating 3 to perform wavelength selection and longitudinal mode selection to form a short-wavelength random laser. In addition, in the corresponding embodiment, by setting the wavelength and tilt angle of the tilted grating 5, not only can the laser at the long-wavelength position of the wide-band laser be lost to obtain a short-wavelength laser, but also the amplified spontaneous radiation can be filtered out and the output power can be stabilized.
[0048] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is only limited by the claims and their full scope and equivalents. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
[0049] Those skilled in the art can understand that, in addition to implementing the system, device, unit and its various modules provided by the present invention in a purely computer-readable program code, it is entirely possible to implement the same program in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers and embedded microcontrollers by logically programming the method steps. Therefore, the system, device and its various modules provided by the present invention can be considered as a hardware component, and the modules included therein for implementing various programs can also be regarded as structures within the hardware component; the modules for implementing various functions can also be regarded as both software programs for implementing the method and structures within the hardware component.
[0050] In addition, all or part of the steps in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including a number of instructions to enable a single-chip microcomputer, a chip or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, RandomAccess Memory), disk or optical disk and other media that can store program codes.
[0051] In addition, various implementations of the embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the embodiments of the present invention, they should also be regarded as the contents disclosed in the embodiments of the present invention.
Claims
1. A device for generating short-wavelength random laser, comprising: A laser unit and an oscillating cavity, wherein the oscillating cavity comprises: a short-wavelength high-reflection grating, a double-clad active optical fiber, a tilted grating, and a passive optical fiber connected in sequence, wherein the laser unit is connected to the oscillating cavity, outputs laser light to the oscillating cavity, and after being converted into a wide-band laser by the double-clad active optical fiber gain, the tilted grating is input to consume the laser light at the long-wave position of the wide-band laser, so that the short-wavelength laser light enters the passive optical fiber for Rayleigh scattering, so as to form a reciprocating oscillation with the short-wavelength high-reflection grating, and generate a short-wavelength random laser light.
2. The device for generating short-wavelength random laser according to claim 1, wherein the laser unit comprises: A semiconductor laser and a beam combiner are provided. The semiconductor laser is connected to the input end of a short-wavelength high-reflection grating through the beam combiner to access an oscillation cavity, coupled into a double-clad active optical fiber, and forward pumped to output short-wavelength random laser from an output end of a passive optical fiber.
3. The device for generating short-wavelength random laser according to claim 1, wherein the laser unit comprises: A semiconductor laser and a beam combiner, wherein the semiconductor laser is connected to the output end of a passive optical fiber through the beam combiner to access an oscillation cavity, and is coupled into a double-clad active optical fiber through a tilted grating and a passive optical fiber in the reverse direction for reverse pumping, so that short-wavelength random laser is output from the output end of the beam combiner.
4. The device for generating short-wavelength random laser according to claim 1, wherein the laser unit comprises: A semiconductor laser and a beam combiner are provided. The semiconductor laser is connected to the output end of a double-clad active optical fiber through the beam combiner to access an oscillator cavity for reverse pumping, so that short-wavelength random laser is output from the output end of the passive optical fiber.
5. The device for generating short-wavelength random laser according to any one of claims 1 to 4, wherein the wavelength of the short-wavelength high-reflection grating is located in the short-wave range within the emission band of the double-clad active optical fiber, and the reflectivity of the short-wavelength high-reflection grating is >99%.
6. The device for generating short-wavelength random laser according to any one of claims 1 to 4, wherein the double-clad active optical fiber is any one of: ytterbium-doped optical fiber, erbium-doped optical fiber, and thulium-doped optical fiber.
7. The device for generating short-wavelength random laser according to any one of claims 1 to 4, wherein the tilted grating wavelength is set at the maximum position of the emission cross-sectional parameter of the double-clad active optical fiber, and the tilt angle of the tilted grating is 45°.
8. The device for generating short-wavelength random laser according to any one of claims 1 to 4, wherein the output end of the passive optical fiber is inclined at an angle of 8°.
9. The device for generating short-wavelength random laser according to any one of claims 1 to 4, wherein the tilted grating is inscribed on either a double-clad active optical fiber or a passive optical fiber.
10. A method for generating short wavelength random laser, comprising: The operating wavelength of the semiconductor laser is set to be within the absorption band of the double-clad active optical fiber; the wavelength of the short-wavelength high-reflection grating is set to be within the short-wavelength range of the emission band of the double-clad active optical fiber; Setting the tilted grating wavelength to be located at the maximum position of the emission cross-sectional parameter of the double-clad active optical fiber; The semiconductor laser is started to output laser, which is then gained into a wide-band laser through a double-clad active optical fiber. Then, the laser at the long-wave position of the wide-band laser is lost through a tilted grating, so that the short-wavelength laser enters the passive optical fiber for Rayleigh scattering and forms a reciprocating oscillation with a short-wavelength high-reflection grating to perform wavelength selection and longitudinal mode selection, and then output a short-wavelength random laser.