30 results about "Chirped pulse amplification" patented technology

The invention relates to an all-fiber sub-hundred femtosecond laser based on an SESAM. The all-fiber sub-hundred femtosecond laser comprises the SESAM, a wavelength division multiplexer, a pumping source, a pumping protector, a gain fiber, a chirp fiber bragg grating, an isolator, a reflector, a compression unit and an autocorrelator. According to the invention, the chirp fiber bragg grating with the dispersion amount of 0.115 ps / nm is adopted to compensate positive dispersion in the cavity, so that mode-locked pulse with the spectral width of 23nm is realized. A transmission-type diffraction grating pair is adopted, the pulse width is compressed to 88fs, and the maximum spectral width 27nm is obtained under the dispersion of 0.00087 ps2 in a near-zero cavity. The condition that the optimal spectral bandwidth of the optimal seed source pulse based on the optical fiber chirped pulse amplification laser should be larger than 15 nm is met, and the compression pulse distortion of the amplifier is reduced. By adopting the linear cavity, the SESAM is adhered to the surface of the single-mode optical fiber patch cord for starting mode locking, so that an all-optical-fiber structure of the system is realized, and the single-mode optical fiber patch cord is suitable for industrial integrated application.

The invention relates to a four-mode synchronous imaging system and method based on chirped pulse amplification. The four-mode synchronous imaging system comprises a light source module, a photoacoustic light source broadening module, an optical coherence imaging module, a first light path conduction module, a high-speed scanning module, a second light path conduction module, an image acquisition module, a detection module and a photoacoustic signal processing module, and the light source module comprises a chirp amplification laser; the four-mode synchronous imaging system effectively realizes simultaneous detection of four imaging modes through a single parameter chirp amplification laser in combination with advanced optical and image processing technologies, improves the multi-dimensional information acquisition capability of imaging, simplifies the design of a multi-mode microscopic imaging system, reduces the complexity and cost of the system, and improves the detection efficiency. Meanwhile, the imaging efficiency and accuracy are improved, synchronous detection of various biological information can be achieved, and the method has wide application prospects, especially in the fields of medical pathology detection, neuroscience and the like.

The invention relates to a femtosecond pulse generation system and method, and the system comprises a pulse seed source which is used for generating a seed pulse; the gain management nonlinear amplification module is used for performing nonlinear spectrum broadening on the seed pulse and accumulating linear chirp, and the gain management nonlinear amplification module is configured to enable the seed pulse to undergo nonlinear self-phase modulation and dynamic gain synergistic effect to form a nonlinear attractor; the stretcher is used for carrying out time domain broadening on the pulse subjected to spectrum broadening; the at least one-stage amplifier is used for performing power amplification on the pulse after the time domain broadening; and the compressor is used for carrying out time domain compression on the pulse and outputting the compressed femtosecond pulse. According to the femtosecond pulse generation system and method, the limitation of gain bandwidth on output pulse width in the traditional chirped pulse amplification technology can be broken through, and high-power femtosecond pulses with the pulse width smaller than 100 fs can be directly output.

The invention discloses a 2-micron short-period laser amplifier based on a thulium-doped positive dispersion fluorotellurite optical fiber, which can solve the problem that a negative dispersion thulium-doped optical fiber is not suitable for performing gain management nonlinear amplification on a 2-micron pulse, and can obtain a pulse width lt. 50 fs, and single pulse energy gt; the femtosecond laser output device has the advantages of being full-fibrillated and compact in structure. The 2-micron femtosecond seed source is femtosecond pulse laser of a 2-micron wave band generated based on nonlinear amplification loop mirror mode locking; the chirped pulse amplifier is used for obtaining sub-picosecond 1.9 mu m femtosecond laser output with the average power greater than or equal to 1W; the optical fiber GMN amplifier is used for obtaining a few-period femtosecond pulse; the high-power optical fiber pulse compressor is a hollow-core optical fiber and is used for carrying out accurate dispersion compensation and high-quality pulse compression.

The invention relates to the technical field of femtosecond pulse measurement, in particular to a dispersion scanning pulse self-measurement method based on a chirped pulse amplification laser, which comprises the following steps of: jointly using a stretcher and a compressor which are arranged in the laser as a dispersion scanning system, and adopting a dispersion scanning coordination strategy; continuously adjusting the dispersion amount of the stretcher and the dispersion amount of the compressor, synchronously collecting second harmonic spectrum signals under different dispersion distribution combinations, and constructing a second harmonic spectrum track diagram; according to the method, an adaptive dispersion coupling phase reconstruction algorithm is adopted, iteration processing is conducted on a second harmonic frequency spectrum track diagram, a high-order dispersion compensation item is introduced for optimization, the time domain intensity and phase information of laser pulses are reconstructed, the optimal dispersion compensation amount is determined, and the narrowest pulse width value is output. Therefore, the precision of pulse phase and width measurement and the convergence speed of the algorithm are improved.

The invention discloses a chirped pulse amplification system and a chirped pulse amplification method based on a mixed gain medium, which efficiently restrain the problem of gain narrowing in the chirped pulse amplification process under the condition of not depending on spectrum shaping by utilizing the characteristic that the central wavelengths of emission spectrums of different types of gain media are different. And optical elements are not additionally introduced, so that energy loss caused by spectrum shaping in the amplification process is avoided, and a reliable technical path is provided for realizing efficient broadband amplification and sub-picosecond output.

In order to solve the problems existing in the existing high-power and high-energy femtosecond fiber amplification system, such as poor beam quality, low output energy, and high system integration complexity under the condition of high-power femtosecond output, the present invention provides a hybrid high-power and high-energy femtosecond chirped pulse amplification system and method. The amplification system and method of the present invention use a silicate glass fiber amplifier to form a pre-amplification system, cascade a single-crystal fiber with a single-pass structure as the main amplifier, abandon the use of an isolator based on a Faraday rotator, prevent the distortion of the beam quality caused by the thermal effect of the Faraday rotator crystal, self-assemble an isolator, and adopt a simple combination of independent devices of a polarization beam splitter prism and a quarter-wave plate, eliminating the thermal lens effect of the Faraday rotator and improving the beam quality. By using as few lenses as possible and a single-pass amplification structure, the optical path is simple, stable and reliable; by using aperture spatial filtering, a high beam quality output under a high power of more than 100 W is obtained.

The invention discloses a lanthanum ion doped oxygen calcium yttrium borate nonlinear optical crystal material and a preparation method thereof, the lanthanum ion doped oxygen calcium yttrium borate nonlinear optical crystal material belongs to a monoclinic system, the space group is Cm, the chemical formula is La0.1: Y0. 9Ca4O (BO3) 3, the frequency multiplication coefficient is 2 * KDP, the ultraviolet cut-off edge is less than 200 nm, and no absorption peak with the intensity greater than or equal to 0.2 cm <-1 > exists in the range of 200-2500 nm. Therefore, the lanthanum ion doped yttrium calcium oxide borate crystal can be used as a nonlinear optical material with a wide application prospect in the field of optical parameter chirped pulse amplification.

The utility model relates to four program femtosecond laser compressor, through the light of first time through the compressor output is injected into the compressor for many times, incident chirp pulse is along the compressor light path and is emitted four times, total transmission grating 8 times, finally through the output mirror output completes compression output, make the number of times of light beam through grating increase to 16 times, make the same grating aperture and grating spacing compressor dispersion quantity turn 4 times, adapt to bigger spread width or bigger bandwidth chirp pulse amplifier, many times repeat, expand the use number of times of compression grating, obtain bigger compression under the condition that the grating spacing of compressor is unchangeable, can be compatible with bigger spread width of chirp pulse amplifier, solve the problem of design limit of chirp pulse amplifier, promote femtosecond laser output single pulse energy.

According to the four-way femtosecond laser compressor and the method, light output through the compressor for the first time is injected into the compressor for multiple times, incident chirped pulses enter and exit for four times along the light path of the compressor, the incident chirped pulses pass through a transmission grating for eight times in total, and finally the incident chirped pulses are output through an output reflector to complete compression output; the number of times that a light beam passes through the grating is increased to 16, so that the dispersion amount of a compressor with the same grating caliber and grating spacing is increased by 4 times, and the chirped pulse amplifier with larger spreading amount or larger bandwidth is adapted; according to the femtosecond laser, the use frequency of the compression grating is expanded repeatedly, and a larger compression amount is obtained under the condition that the space between the compression grating is not changed, so that the larger broadening amount of the chirped pulse amplifier can be compatible, the problem of design limitation of the chirped pulse amplifier is solved, and the output monopulse energy of the femtosecond laser is improved.

The invention discloses a samarium-doped oxygen calcium lanthanum borate nonlinear optical crystal material for pulse amplification and a preparation method and application thereof.The crystal material belongs to a monoclinic system, an m point group and a Cm space group, the chemical formula is Smx: La1-xCa4O (BO3) 3, x is 0.1-0.99, the thermal diffusivity is 0.865 mm / s and 0.531 mm / s at the temperature of 300 K and 600 K respectively, the specific heat capacity is 0.691 J.g <-1 >. K <-1 > and 0.871 J.g <-1 >. K <-1 > at the temperature of 300 K and 600 K respectively, and the samarium-doped oxygen calcium lanthanum borate nonlinear optical crystal material is a samarium-doped oxygen calcium lanthanum borate nonlinear optical crystal material. And the transmittance of the samarium-doped oxygen calcium lanthanum borate crystal material in the range of 500-900 nm and the transmittance of the samarium-doped oxygen calcium lanthanum borate crystal material in the range of 1600-2400 nm reach 85% or above, so that the samarium-doped oxygen calcium lanthanum borate crystal material can be used as a nonlinear optical crystal material with a wide application prospect in a quasi-parametric chirped pulse amplification system.

The invention discloses a broadband spectrum laser pulse energy amplification method, and belongs to the technical field of ultrafast laser, and the method comprises the steps: sequentially carrying out the spectrum broadening, difference frequency and pulse time domain broadening of a titanium sapphire kilohertz laser pulse, and carrying out the pre-compensation of high-order dispersion introduced in the subsequent pulse energy amplification process; a double-chirp optical parametric amplification technology is utilized, a first wave band in the obtained infrared seed laser pulse is amplified to a first set value, a second wave band is pre-amplified to a second set value, and the first wave band is smaller than the second wave band; the chirped pulse amplification technology is utilized, a third wave band in the infrared seed laser pulse is amplified to a third set value, and the third wave band covers the long wave band in the first wave band and the second wave band; and performing pulse time domain compression on the output infrared seed laser pulse to obtain an infrared seed laser pulse with a near Fourier transform limit pulse width. According to the method, the high-peak-power single-optical-period infrared laser pulse can be obtained.

The application belongs to the field of femtosecond laser technology, and particularly relates to a few-cycle high-energy fiber chirped pulse amplification system and method. The system comprises a seed source module, a chirped pulse amplification module and a hybrid compression module. The seed source module adopts a nonlinear polarization rotation mode-locked resonator with an integrated tunable filter to generate linear chirped wide spectrum seed pulses with tunable central wavelength. The chirped pulse amplification module realizes energy amplification while effectively suppressing gain narrowing effect through a three-stage structure of pre-chirp management, pre-amplification and main amplification. The hybrid compression module adopts a cascaded scheme of a diffraction grating compressor and a fiber soliton self-compressor to finally compress the pulse width to two optical periods. The application solves the problem that high energy and few cycles are difficult to be considered in a C-band fiber amplification system, and can output high peak power pulses of hundreds of nanojoules and two optical periods.

The invention provides a phase delay self-compensating vector polarized light parametric chirped pulse amplifier which comprises a narrow-band pulse laser, a broadband pulse laser generating device, a half-wave plate, a polarization beam splitter, a pulse stretcher, a laser mode converter, a first nonlinear crystal, a second nonlinear crystal and a pulse compressor. The phase delay introduced by the second-stage optical parameter chirped pulse amplification to the two orthogonal polarization components of the vector polarization signal light is used for counteracting the dynamic phase delay accumulated in the first-stage optical parameter chirped pulse amplification process. The objective of the invention is to solve the problem of polarization distortion of vector polarized light caused by different accumulated phase delays of all frequency components in the optical parameter chirped pulse amplification process, so that the vector polarized light can obtain broadband high-gain amplification while the initial polarization characteristic of the vector polarized light is kept unchanged. Vector polarized light parametric chirped pulse amplification with high polarization purity and high peak power is realized.

The invention provides an improved chirped pulse amplification system, a spectrum modulation method and application. According to the improved chirped pulse amplification system, the spectrum modulation method and the application, the spectrum distortion effect in the chirped pulse amplification process is effectively inhibited, and the pulse compressibility degradation caused by gain narrowing and spectrum red shift in the chirped pulse amplification process is inhibited; according to the improved chirped pulse amplification system and the spectrum modulation method, the peak power of an ultrafast laser can be remarkably improved, the pulse width can be remarkably reduced, and therefore the gain narrowing and spectrum red shift phenomena are restrained, and the improved chirped pulse amplification system and the spectrum modulation method are suitable for an ultrafast laser system needing to overcome the gain narrowing caused by the chirped pulse amplification technology.

The invention relates to the technical field of femtosecond laser, and discloses a method and equipment for diagnosing and correcting dispersion distribution of a chirped fiber grating, and a medium. The method comprises the following steps: building a chirped pulse amplification system; adjusting the pulse compressor to enable the autocorrelator to display the narrowest pulse width of the compressed pulse in the current state; inserting a narrowband filter capable of transversely moving into a diffraction light path of the pulse compressor, sequentially shielding spectral components with different wavelengths by transversely moving the narrowband filter, and monitoring a compression pulse time domain shape after shielding different spectral components in real time by using an autocorrelator; determining that the corresponding spectral component is an error spectral component causing dispersion distribution mismatching according to the compression pulse time domain shape; and performing chirp fiber grating dispersion distribution correction on a grid region corresponding to the error spectrum component in the chirp fiber grating according to the determined error spectrum component. Through spectral component scanning, the problem that the high-order dispersion error can be perceived and is difficult to position is solved.

The invention discloses a low-temperature cooling ytterbium-doped femtosecond laser amplifier. The low-temperature cooling system can cool 1-N ytterbium-doped (Yb < 3 + >) gain media at the same time, the system is specially designed to effectively reduce the temperature of the ytterbium-doped gain media, an existing crystal refrigeration mode is that a refrigeration system and crystals are in one-to-one correspondence for cooling, the crystal cooling mode is simplified, the utilization efficiency of the cooling system is improved, and the energy consumption is reduced. And the cost of the femtosecond laser amplifier is reduced. According to the system, through the efficient heat exchanger and the refrigerating machine, all gain media are ensured to operate within the optimal working temperature range, and therefore the laser performance of the system is optimized. The system specifically comprises a plurality of pump light generation systems, a chirped pulse amplification system and a time schedule controller so as to realize efficient laser amplification and thermal management.

The invention belongs to the technical field of femtosecond laser, and particularly relates to a few-period high-energy optical fiber chirped pulse amplification system and method, and the system comprises a seed source module, a chirped pulse amplification module and a mixed compression module. The seed source module adopts a nonlinear polarization rotation mode-locked resonant cavity integrated with a tunable filter to generate a linear chirp wide-spectrum seed pulse with a tunable central wavelength. The chirped pulse amplification module effectively suppresses a gain narrowing effect while realizing energy amplification through a three-stage structure of pre-chirp management, pre-amplification and main amplification. The hybrid compression module adopts a scheme of cascading a diffraction grating compressor and an optical fiber soliton self-compressor, and finally realizes that the pulse width is compressed to two optical periods. According to the invention, the problem that high energy and few periods are difficult to consider in a C-band optical fiber amplification system is solved, and high-peak power pulses with hundred nanojoule magnitude and two optical periods can be output.

A pulse compressor (14) for time-compressing pulsed laser radiation according to a chirped pulse amplification, CPA, scheme, the pulse compressor comprising a first compressor element (14a), and a second compressor element (14b). The first compressor element (14a) is configured to receive as input the pulsed laser radiation and to produce as output first compressed radiation having a first pulse duration. The second compressor element (14b) is configured to receive as input the first compressed radiation and to produce as output second compressed radiation having a second pulse duration. The second pulse duration is shorter than the first pulse duration. The first compressor element (14a) is configured to time-compress the pulse of the pulsed laser radiation of a first compression factor. The second compressor element (14b) is configured to time-compress the pulse of the first compressed radiation of a second compression factor. The first compression factor is larger than the second compression factor.

To perform adequately chirped pulse amplification.SOLUTION: A pulse light generation device 1 includes: an oscillator 2 for oscillating ultrashort pulse light L; a stretcher fiber 7 for widening the time width of the ultrashort pulse light L; a fiber amplifier 8 for amplifying the ultrashort pulse light L the time width of which has been widened by the stretcher fiber 7; and a compressor 9 for compressing the time width of the ultrashort pulse light L which has been amplified by the fiber amplifier 8. The stretcher fiber 7 is configured by combining a first fiber 71 for widening the time width of the ultrashort pulse light L with a first characteristic, and a second fiber 72 for widening the time width of the ultrashort pulse light L with a second characteristic which is different from the first characteristic.SELECTED DRAWING: Figure 8

The application relates to a 1550nm high-stability femtosecond fiber laser, which belongs to the technical field of optoelectronic devices and mainly comprises a single-chip microcomputer module (1), a microwave signal source module (2), a lithium niobate modulator driver (3), a high-speed photoelectric converter (20), an amplitude self-adaptive adjustment circuit (21), a repetition frequency detection circuit (22), a repetition frequency change rate detection circuit (23) and the like. The application realizes all-fiber chirped pulse amplification suitable for a femtosecond fiber laser system, improves the stability of output femtosecond light pulses, and improves the electro-optical conversion efficiency of the whole system.

The application belongs to the technical field of laser, and relates to a high-energy ultrashort pulse laser. The laser comprises a mode-locked fiber laser oscillator, a nonlinear amplifier, a stretcher, a pulse selection module, a pre-amplification stage, a main amplification stage and a compressor. In the laser, the cavity dispersion of the mode-locked fiber laser oscillator is negative dispersion which is designed optimally, and the output pulse is injected into the nonlinear amplifier after pre-chirp management, so that a flat wide spectrum can be obtained; the stretcher, the pulse selection module, the pre-amplification stage, the main amplification stage and the compressor are combined to realize further efficient amplification of the injected pulse. The application can adopt a full polarization maintaining structure which has high stability and reliability, and realizes common use of nonlinear amplification and chirped pulse amplification technology, so that the gain narrowing problem in the traditional chirped pulse amplification process can be overcome, the single pulse energy amplification limit of the nonlinear amplification technology can be broken through, and finally the output of high-energy ultrashort laser pulse is realized.

Chirped pulse amplification with an optical pulse stretcher (13) for dividing an optical input pulse (14) in temporally and spectrally separated collinear pulses and a compressor for applying a negative dispersion to an optical signal (2), the compressor comprising: - a first dispersive element (3); - a second dispersive element (5), wherein the second dispersive element (5) is arranged parallel to the first dispersive element (3) and downstream of the first dispersive element (3); - a reflective element (7) downstream of the second dispersive element (5) configured for reflecting the optical signal (2) onto the second dispersive element (5); and -a first mirror (8) and a second mirror (9) arranged downstream the first dispersive element (3) and upstream of the second dispersive element (4), wherein the first mirror (8) and the second mirror (9) are parallel to each other and are configured for increasing an optical path length of the optical signal (2).

The application discloses an optical parametric chirped pulse amplification method based on field mapping pump beam shaping, wherein a Gaussian light beam output by a pump source is input into a refractive index shaping system to perform flat-top light beam shaping, and a flat-top pump light beam is obtained; a stretcher is used to perform time expansion on signal light, and expanded signal light is obtained; the flat-top pump light beam and the expanded signal light are simultaneously incident on a same position of a nonlinear crystal to perform optical parametric amplification, and amplified signal light is obtained; the pump light beam is shaped from a Gaussian type into a flat-top type through the refractive index shaping system, so that the signal light obtains uniform gain at different spatial positions, and conversion efficiency of the pump light to the signal light is improved; in addition, energy of output light obtained through the refractive index shaping system is almost not lost relative to input light, and the technical problems of low optical parametric chirped pulse amplification efficiency and low pulse space-time quality of the pump light beam in the prior art are solved.

This invention discloses a broadband all-fiber femtosecond laser system based on chirped pulse amplification and its adjustment method. The broadband all-fiber femtosecond laser system includes a broadband dissipative soliton mode-locked fiber laser and an all-fiber chirped pulse amplifier connected together. The broadband dissipative soliton mode-locked fiber laser includes a first pump source, a first wavelength division multiplexer, a first gain fiber, a first polarization controller, a polarization-dependent isolator, a second polarization controller, and a coupler. The all-fiber chirped pulse amplifier includes a first polarization-independent isolator, a dispersion-compensating fiber, a second wavelength division multiplexer, a second gain fiber, a third wavelength division multiplexer, a single-mode fiber, a second polarization-independent isolator, a second pump source, and a third pump source. The system achieves broadband characteristics through fiber length adjustment, spectral adjustment, and micro-adjustment modules. This invention has a simple structure, wide application scenarios, pulse distortion resistance, broad spectrum, and strong anti-interference capability.

This application relates to the field of femtosecond laser technology, and discloses a method, apparatus, and medium for diagnosing and correcting the dispersion distribution of chirped fiber gratings. The method involves constructing a chirped pulse amplification system; adjusting the pulse compressor so that the compressed pulse, as displayed by an autocorrelator, exhibits the narrowest pulse width under the current state; inserting a laterally movable narrowband filter into the diffraction path of the pulse compressor, sequentially blocking different wavelength spectral components by moving the filter laterally, and using an autocorrelator to monitor the time-domain shape of the compressed pulse after blocking different spectral components in real time; determining the corresponding spectral component as the error spectral component causing the dispersion distribution mismatch based on the time-domain shape of the compressed pulse; and correcting the dispersion distribution of the chirped fiber grating in the grating region corresponding to the determined error spectral component based on the determined error spectral component. By scanning the spectral components, the problem of "perceptible but difficult to locate" high-order dispersion errors is solved.

The invention discloses an oscillation mode optical parameter chirped pulse amplification laser and method. The core of the system is to construct a composite resonant cavity, and the cavity partially shares a key optical element, so that the resonant cavity of the slab regenerative amplifier and the resonant cavity of the synchronous pump optical parametric oscillator (OPO) are physically coupled. The specific scheme is as follows: a broadened picosecond chirp seed pulse is injected into a regenerative amplifier for energy amplification; the method is characterized in that the amplified high-energy chirped pulse is directly used as pump light, and the pump light is embedded in a common nonlinear crystal in the composite cavity to excite optical parametric oscillation. Two processes of'chirp pulse regenerative amplification 'and'synchronous pump optical parametric oscillation' are synchronously generated in a composite resonant cavity which is overlapped in time and space, so that energy is circularly extracted from chirp pump light in multiple oscillation processes of OPO signal light, and a unique'oscillation mode OPCPA 'is formed.

A laser system and method. In one example, the laser system includes an optical pulse stretcher configured to stretch pulse durations of an input train of input pulses to produce a train of stretched laser pulses, a pulse replicator module configured to increase a pulse repetition rate of the train of stretched laser pulses to produce a modified pulse train of laser light, a fiber power amplifier configured to amplify the modified pulse train to produce amplified laser pulses, and a pulse compressor that temporally compresses the amplified laser pulses to produce amplified and compressed laser pulses. The system may further include a nonlinear frequency conversion stage comprising at least one nonlinear crystal.

Ultrashort pulsed laser systems are described. In one example, a pulsed laser system includes a source laser configured to emit a pulsed source laser beam, a splitter configured to split the source laser beam into first and second input laser beams, a first amplifier module configured to amplify the first input laser beam using chirped pulse amplification (CPA) and to produce, at a first output port, a first output laser beam in a first spectral range based on soliton self-frequency shift (SSFS) in the first amplifier module, a second amplifier module configured to amplify the second input laser beam using CPA and to produce an intermediate beam based on SSFS in the second amplifier module, and a mid-infrared fiber configured to receive the intermediate beam and to produce, at a second output port, a second output laser beam in a second spectral range based SSFS in the mid-infrared fiber.

The application relates to the field of solid ultrafast laser technology, in particular to a kind of middle infrared high-power femtosecond laser atherosclerotic tissue ablation device and method, including the chirp pulse amplification module for generating high-power femtosecond pump light in signal light path; middle infrared femtosecond laser generation module for generating 5.75 microns middle infrared high-power laser through two-stage optical parametric amplification module; atherosclerotic ablation module for outputting 5.75 microns external high-power femtosecond laser to ablate atherosclerotic tissue. Atherosclerotic tissue can be removed efficiently, minimally invasively and selectively.