Laser with adjustable pulse width
By designing a pulse width adjustable laser of a broadband spectral laser and a pulse width adjustment module, the problem of inflexible output parameters caused by the internal and external adjustment methods of the cavity in the prior art is solved, and flexible adjustment of the spectral width and band of the laser output is achieved, which is suitable for environments in different scenarios.
Patent Information
- Application Number
- CN202421712022.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-19
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-07-19
AI Technical Summary
In the existing pulse width adjustable lasers in the cavity, the adjustment of the dispersion and modulation depth in the cavity will lead to changes in parameters such as output power and spectrum, and the control accuracy requirements are extremely high and the flexibility is poor.
A pulse width adjustable laser including a broadband spectral laser and a pulse width adjustment module is designed. The broadband spectral laser outputs wide spectrum pulse laser through the fiber laser and the amplification module. The pulse width adjustment module uses an adjustable fiber filter or other optical components to achieve output of different pulse widths by adjusting the spectral bandwidth and band.
It realizes flexible adjustment of the spectral width and band of the laser output, and the output parameters are varied, suitable for environments in different scenarios, improving the adaptability and flexibility of pulse width adjustable lasers.
Smart Images
Figure CN222996028U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lasers, in particular to a pulse-width adjustable laser. Background Art
[0002] The environments used in high-end fields such as industrial laser cutting and biomedicine are diverse, and there are different requirements for laser parameters. The ultrashort pulse tunable laser has the advantages of adjustable pulse width, variable peak power, high efficiency, etc. It is flexible and variable, and has strong adaptability. It can be applied to many different fields such as laser cutting, biomedicine, nonlinear optics, and fiber sensing. The current pulse-width adjustable methods mainly include intracavity and extracavity adjustment methods such as grating broadening and compression, and modulation depth adjustment of saturable absorbers. The adjustment of intracavity dispersion and modulation depth will cause changes in parameters such as output power and spectrum, and extremely high precision is required for control. Extracavity mainly compensates for dispersion by adding a dispersion compensation grating or hollow-core fiber, and it remains fixed after adjustment, with poor flexibility.
[0003] As is well known, there is a parameter time-bandwidth product in the laser field, which refers to the product of the width of the pulse in the time domain and the width of the spectrum in the frequency domain of the ultrashort pulse being a constant value. According to the principle of Fourier transform, to generate a narrow pulse, the spectrum must reach a certain width. For example, to generate a pulse with a central wavelength of 800 nm and a width of 10 fs, the spectrum should be at least about 100 nm. That is to say, there is a minimum value for the time-bandwidth product. If the time-bandwidth product is larger than this minimum value, it means that this pulse still has the possibility of further compression in the time domain. Therefore, according to this principle, by adding different types of filtering devices outside the cavity of the ultrabroadband spectral femtosecond laser oscillator to control the broadband and band of the output spectrum, different pulse-width outputs can be finally compressed. Summary of the Utility Model
[0004] Therefore, the technical problem to be solved by the utility model is to overcome the deficiencies in the prior art and provide a pulse-width adjustable laser, which can change the spectral width and band of the output laser through a pulse-width adjustment module, has a flexible adjustable method, variable output parameters, and is suitable for environments in different scenarios.
[0005] To solve the above technical problem, the utility model provides a pulse-width adjustable laser, including:
[0006] A broadband spectral laser for outputting broadband spectral pulsed laser, the broadband spectral laser includes a fiber laser and an amplification module, and the amplification module is used to receive the laser output by the fiber laser and amplify the laser power and broaden the spectrum;
[0007] A pulse-width adjustment module for adjusting the pulse width of the laser output by the amplification module.
[0008] In one embodiment of the present utility model, a compressor is further included, and the laser output by the pulse width adjustment module passes through the compressor to output lasers with different pulse widths.
[0009] In one embodiment of the present utility model, the fiber laser includes a first pump, a semiconductor saturable absorber mirror, a first wavelength division multiplexer, a first ytterbium-doped fiber, a chirped fiber grating, and a first isolator; the semiconductor saturable absorber mirror, the first wavelength division multiplexer, the first ytterbium-doped fiber, the chirped fiber grating, and the first isolator are sequentially connected through a transmission fiber to form a fiber resonant cavity. The first pump generates pump light and enters the fiber resonant cavity through the first wavelength division multiplexer, and the output end of the first isolator outputs laser pulses.
[0010] In one embodiment of the present utility model, the semiconductor saturable absorber mirror adopts a fiber-compatible device formed by directly contacting the fiber end face of the signal end of the first wavelength division multiplexer.
[0011] In one embodiment of the present utility model, the amplification module is a single-stage amplification module or a multi-stage amplification module, and the multi-stage amplification module is formed by cascading multiple single-stage amplification modules in series.
[0012] In one embodiment of the present utility model, the single-stage amplification module includes a second pump, a second wavelength division multiplexer, a second ytterbium-doped fiber, and a second isolator. The pump light generated by the second pump enters the transmission fiber through the second wavelength division multiplexer, and the second ytterbium-doped fiber is arranged between the second wavelength division multiplexer and the second isolator.
[0013] In one embodiment of the present utility model, the pulse width adjustment module is an adjustable fiber filter. By adjusting the adjustable fiber filter, outputs with different spectral bandwidths and bands are achieved, and lasers with different pulse widths are output.
[0014] In one embodiment of the present utility model, the pulse width adjustment module includes a first collimator, a polarization beam splitter prism, a wave plate, a prism pair, a first shutter, and a reflector. The first collimator receives the wide-spectrum laser output by the amplification module. The wide-spectrum laser sequentially passes through the polarization beam splitter prism, the wave plate, the prism pair, the first shutter, and the reflector. Finally, the laser is horizontally reflected by the reflector and returns along the original path through the refraction of the first shutter and the prism pair. The polarization direction of the laser is changed by the wave plate, and finally, lasers with different widths and bands are output through the polarization beam splitter prism.
[0015] In one embodiment of the present utility model, the wave plate is a half-wave plate.
[0016] In an embodiment of the present utility model, the pulse width adjustment module includes a second collimator, a single prism, and a second shutter. The second collimator receives the broadband spectrum laser output by the amplification module, and the broadband spectrum laser is output after passing through the single prism and the second shutter in sequence; by adjusting the spatial relative position of the second shutter and the size of the shutter through-hole, lasers with different spectral bandwidths and bands are output.
[0017] The above technical solution of the present utility model has the following advantages compared with the prior art:
[0018] For a pulse width adjustable laser described in the present utility model, the spectral width and band of the output laser can be changed through the pulse width adjustment module. The adjustable method is flexible, the output parameters are variable, and it is applicable to the environments of different scenarios. Description of the Drawings
[0019] In order to make the content of the present utility model easier to be clearly understood, the following further details the present utility model according to the specific embodiments of the present utility model in combination with the drawings, where
[0020] Figure 1 is a schematic structural diagram of a pulse width adjustable laser in a preferred embodiment of the present utility model;
[0021] Figure 2 is Figure 1 a schematic structural diagram of a broadband spectrum laser of the pulse width adjustable laser shown;
[0022] Figure 3 is Figure 1 a schematic structural diagram of an amplification module of the pulse width adjustable laser shown;
[0023] Figure 4 is a schematic structural diagram of Embodiment 1 of the present invention;
[0024] Figure 5 is a schematic structural diagram of Embodiment 2 of the present invention;
[0025] Figure 6 is a schematic structural diagram of Embodiment 3 of the present invention;
[0026] Explanation of the reference numerals in the drawings of the specification: 1. Broadband spectrum laser; 11. Fiber laser; 111. First pump; 112. Semiconductor saturable absorber mirror; 113. First wavelength division multiplexer; 114. First ytterbium-doped fiber; 115. Chirped fiber grating; 116. First isolator; 12. Amplification module; 121. Second pump; 122. Second wavelength division multiplexer; 123. Second ytterbium-doped fiber; 124. Second isolator; 2. Pulse width adjustment module. Detailed Embodiments
[0027] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments cited do not limit the present invention.
[0028] Referring to Figure 1 As shown, a pulse-width adjustable laser of the present invention includes:
[0029] A broadband spectral laser 1 for outputting broadband spectral pulsed laser. The broadband spectral laser 1 includes a fiber laser 11 and an amplification module 12. The amplification module 12 is used to receive the laser output by the fiber laser 11 and amplify the laser power and broaden the spectrum;
[0030] A pulse-width adjustment module 2 for adjusting the pulse width of the laser output by the amplification module 12.
[0031] Further, a compressor is further included. The laser output by the pulse-width adjustment module passes through the compressor to output lasers with different pulse widths.
[0032] As Figure 2 As shown, the fiber laser 11 includes a first pump 111, a semiconductor saturable absorber mirror 112, a first wavelength division multiplexer 113, a first ytterbium-doped fiber 114, a chirped fiber grating 115, and a first isolator 116; the semiconductor saturable absorber mirror 112, the first wavelength division multiplexer 113, the first ytterbium-doped fiber 114, the chirped fiber grating 115, and the first isolator 116 are sequentially connected by a transmission fiber to form a fiber resonator. The first pump 111 generates pump light and enters the fiber resonator through the first wavelength division multiplexer 113, and the output end of the first isolator 116 outputs laser pulses.
[0033] In this embodiment, the semiconductor saturable absorber mirror 112 is a fiber-compatible device formed by directly contacting the fiber end face of the signal end of the first wavelength division multiplexer 113.
[0034] Among them, the amplification module 12 is a single-stage amplification module or a multi-stage amplification module, and the multi-stage amplification module is formed by cascading multiple single-stage amplification modules in series.
[0035] Preferably, the single-stage amplification module includes a second pump 121, a second wavelength division multiplexer 122, a second ytterbium-doped fiber 123, and a second isolator 124. The pump light generated by the second pump 121 enters the transmission fiber through the second wavelength division multiplexer 122. The second ytterbium-doped fiber 123 is disposed between the second wavelength division multiplexer 122 and the second isolator 124 and is used to amplify the power of the laser.
[0036] As Figure 3As shown, in this embodiment, it is a multi-stage amplification module. The multi-stage amplification module includes a first-stage amplification module, a second-stage amplification module, and a third-stage amplification module. The first-stage amplification module has the same structure as the first-level amplification module. The second-stage amplification module and the third-stage amplification module have the same structure, and both include a third pump, a first beam combiner, a third ytterbium-doped fiber, and a high-definition isolator. The pump light emitted by the third pump enters the transmission fiber through the first beam combiner, then sequentially passes through the third ytterbium-doped fiber to amplify the laser power, and finally is emitted through the high-definition isolator.
[0037] As Figure 4 shown, in this embodiment, the pulse width adjustment module 2 is an adjustable fiber optic filter. By adjusting the adjustable fiber optic filter, outputs with different spectral bandwidths and bands are achieved, and lasers with different pulse widths are output.
[0038] An adjustable fiber optic filter is added outside the ultra-wideband spectral laser 1. By adjusting the adjustable fiber optic filter, outputs with different spectral bandwidths and bands are achieved, and finally lasers with different pulse widths are compressed.
[0039] Embodiment 2
[0040] As Figure 5 shown, the pulse width adjustment module 2 includes a first collimator 21, a polarization beam splitter prism 22, a wave plate 23, a prism pair 24, a first shutter 25, and a mirror 26. The first collimator 21 receives the wide-spectrum laser output by the amplification module. The wide-spectrum laser sequentially passes through the polarization beam splitter prism 22, the wave plate 22, the prism pair 24, the first shutter 25, and the mirror 26. Finally, the laser is horizontally reflected by the mirror 26 and sequentially passes through the first shutter 25 and the refraction of the prism pair 24 to return along the original path. The polarization direction of the laser is changed by the wave plate 23, and finally, lasers with different widths and bands are emitted through the polarization beam splitter prism 22.
[0041] Preferably, the wave plate 23 is a half-wave plate.
[0042] During operation, the broadband spectral laser 1 generates broadband laser light that sequentially passes through the first collimator 21. The polarization beam splitter prism 22 transmits the horizontally polarized light. The horizontally polarized light rotates clockwise by 45° after passing through a direction that is 22.5° with respect to the fast axis of the half-wave plate and further transmits into the prism pair 24. The refraction of the laser through the prism pair 24 disperses the light of different wavelength bands of the light beam. After the prism pair 24, the laser passes through the first shutter 25 with a variable relative spatial position and a variable diameter of the inner laser-transmitting circular aperture. When the first shutter changes the size of the inner circular aperture and the relative spatial position of the optical path, the spectral width and wavelength band that can pass through are different, and other unwanted light is blocked by the first shutter 25 and cannot pass through. The light passing through the through-hole is horizontally reflected by the mirror 26 and returns along the original path through the refraction of the first shutter 25 and the prism pair 24, as shown by the dotted arrow in the figure. Finally, the polarization direction of the laser is changed clockwise by 45° through the half-wave plate to form vertically polarized laser light, and finally, laser light with different widths and wavelength bands is output through the other path of the polarization beam splitter prism 22, and then the desired pulse width is compressed by the compressor.
[0043] Embodiment 3
[0044] As Figure 6 shown, the pulse width adjustment module 2 includes a second collimator 27, a single prism 28, and a second shutter 29. The second collimator 27 receives the broadband laser light output by the amplification module, and the broadband laser light sequentially passes through the single prism 28 and the second shutter 29 and then outputs; by adjusting the relative spatial position of the second shutter 29 and the size of the through-hole of the second shutter 29, laser light with different spectral broadband and wavelength bands is output.
[0045] During operation, the broadband laser light generated by the broadband spectral laser 1 passes through the second collimator 27 and then enters the single prism 28. The refraction of the single prism 28 disperses the light of different wavelength bands of the light beam, and finally exits from the second shutter; when the second shutter 29 changes the size of the inner circular aperture and the relative spatial position of the optical path, the spectral width and wavelength band that can pass through are different.
[0046] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.
Claims
1. A pulse width adjustable laser, characterized in that: include: A broadband spectrum laser, used for outputting broadband spectrum pulsed laser, the broadband spectrum laser comprising a fiber laser and an amplification module, the amplification module being used for receiving the laser outputted by the fiber laser and amplifying the laser power and broadening the spectrum; A pulse width modulation module is used to modulate the pulse width of the laser output by the amplification module. The pulse width modulation module includes a first collimator, a polarization beam splitter prism, a wave plate, a prism pair, a first light gate and a reflector. The first collimator receives the wide-spectrum laser output by the amplification module. The wide-spectrum laser passes through the polarization beam splitter prism, the wave plate, the prism pair, the first light gate and the reflector in sequence. Finally, the laser is horizontally reflected by the reflector and returns to the original path through the refraction of the first light gate and the prism pair in sequence. The polarization direction of the laser is changed by the wave plate, and finally, lasers of different widths and bands are emitted through the polarization beam splitter prism.
2. A pulse width adjustable laser according to claim 1, characterized in that: It also includes a compressor, and the laser output by the pulse width adjustment module is output as laser with different pulse widths through the compressor.
3. The pulse width adjustable laser according to claim 1, characterized in that: The fiber laser comprises a first pump, a semiconductor saturable absorber, a first wavelength division multiplexer, a first ytterbium-doped fiber, a chirped fiber grating and a first isolator; the semiconductor saturable absorber, the first wavelength division multiplexer, the first ytterbium-doped fiber, the chirped fiber grating and the first isolator are sequentially connected to form a fiber resonant cavity through a transmission fiber, the first pump generates pump light which enters the fiber resonant cavity through the first wavelength division multiplexer, and the output end of the first isolator outputs a laser pulse.
4. A pulse width adjustable laser according to claim 3, characterized in that: The semiconductor saturable absorber mirror is formed into a fiber-compatible device by directly contacting the fiber end face of the signal end of the first wavelength division multiplexer.
5. The pulse width adjustable laser according to claim 1, characterized in that: The amplification module is a single-stage amplification module or a multi-stage amplification module, and the multi-stage amplification module is formed by cascading a plurality of single-stage amplification modules in series.
6. The pulse width adjustable laser according to claim 5, characterized in that: The first-stage amplification module includes a second pump, a second wavelength division multiplexer, a second ytterbium-doped optical fiber and a second isolator. The pump light generated by the second pump enters the transmission optical fiber through the second wavelength division multiplexer. The second ytterbium-doped optical fiber is arranged between the second wavelength division multiplexer and the second isolator.
7. The pulse width adjustable laser according to claim 1, characterized in that: The pulse width adjustment module is an adjustable optical fiber filter, which can output different spectral bandwidths and bands by adjusting the adjustable optical fiber filter, and output lasers with different pulse widths.
8. The pulse width adjustable laser according to claim 1, characterized in that: The wave plate is a half wave plate.
9. The pulse width adjustable laser according to claim 1, characterized in that: The pulse width modulation module includes a second collimator, a single prism and a second optical gate. The second collimator receives the wide-spectrum laser output by the amplification module, and the wide-spectrum laser is output after passing through the single prism and the second optical gate in sequence. The output of lasers with different spectral bandwidths and bands is changed by adjusting the spatial relative position of the second optical gate and the size of the optical gate through hole.