CN209200363U - Sub- THz high power picosecond optical fiber laser based on MOPA structure - Google Patents

Abstract

The utility model relates to a kind of sub- THz high power picosecond optical fiber laser based on MOPA structure, including by sequentially connected picosecond of optical fiber laser seed source of optical fiber, frequency upgrading part and amplifier section；Described picosecond of optical fiber laser seed source uses linear short bore configurations, the output end of described picosecond of optical fiber laser seed source is connected to the input terminal of the frequency upgrading part, the frequency upgrading part is made of cascade 50/50 fiber coupler, and the output end of the frequency upgrading part is connected to the input terminal of the amplifier section；Described picosecond of optical fiber laser seed source generates upper frequency picosecond pulse signal, the high repetition frequency picosecond pulse signal that signal boost is Asia THz by the frequency upgrading part, power amplification is carried out by the amplifier section again, exports the high power picosecond pulse signal of Asia THz high repetition frequency.The utility model mounting structure is simple, it is easy to accomplish, it is low in cost, convenient for promoting.

Description

Sub- THz high power picosecond optical fiber laser based on MOPA structure

Technical field

The utility model relates to laser technology fields, and in particular to a kind of sub- THz high power picosecond based on MOPA structure Optical fiber laser.

Background technique

High power picosecond optical fiber laser is with beam quality is good, thermal stability is high, gain band is wide, peak power It is high, compact-sized, at low cost, material " cold " can be burnt, Maintenance free the advantages that, in industrial materials processing, biomedical, super Continuous spectrum generates and the fields such as remote sensing survey have a wide range of applications, and has become a hot topic of research in recent years.High power is obtained at present The main method of picosecond optical fiber laser is that (MOPA, master are amplified in passive mode-locking fiber laser and seed light main oscillations Oscillator power amplifier), passive mode-locking fiber laser obtains the output of lower-wattage pulse laser, then leads to MOPA amplification is crossed, realizes and is exported compared with high pulse energy and the laser signal of mean power.

In addition, needing optical fiber laser that there is high repetition frequency, the height of optical fiber laser in the application of optical frequency com Repetition rate can increase comb teeth interval, and the requirement of frequency measurement application is met with this；The high-precision visual direction speed in astronomical observation The scientific researches such as degree Scaling Problem, accurate distance measurement, precision lidar, national defence, which are also required to optical fiber laser, has high repeat Frequency.Currently, in optical fiber laser there are mainly three types of the methods of realization high repetition frequency: active mode locking, harmonic mode locking and short cavity Mode locking.Wherein, active mode locking method needs to increase in resonant cavity the active modulators parts such as acousto-optic, electric light, therefore pulse width It will receive the limitation of electricity bandwidth and system bulky complex；Harmonic mode locking needs increase pump laser power by a relatively large margin The harmonic wave that high repetition frequency can be obtained, due to not being fundamental frequency working condition, the uniformity and stability for obtaining signal be not compared with It is good；For short cavity mode locking since resonant cavity is shorter, dispersion and nonlinear effect are smaller, therefore export pulse stabilization.But short cavity due to It is limited by cavity length of the resonator chamber, is difficult to realize the laser pulse signal of more high repetition frequency.

Utility model content

In view of this, that it is necessary to provide a kind of is high based on MOPA structure with preferable nonlinear characteristic, output power Sub- THz high power picosecond optical fiber laser.

A kind of sub- THz high power picosecond optical fiber laser based on MOPA structure, including picosecond optical fiber laser seed source, Frequency upgrading part and amplifier section, described picosecond of optical fiber laser seed source, the frequency upgrading part and the enlarging section / pass through optical fiber connect；Described picosecond of optical fiber laser seed source uses linear short bore configurations, described picosecond of optical-fiber laser The output end of device seed source is connected to the input terminal of the frequency upgrading part, and the frequency upgrading part is by cascade 50/50 Fiber coupler composition, the output end of the frequency upgrading part are connected to the input terminal of the amplifier section, the enlarging section Divide includes two-stage pre-amplification part and the main amplifier section of two-stage；Described picosecond of optical fiber laser seed source generates high repetition frequency skin Second pulse signal, the high repetition frequency picosecond pulse signal that signal boost is Asia THz by the frequency upgrading part, then pass through two Main amplifier section described in the grade pre-amplification part and two-stage carries out power amplification, exports the high power of Asia THz high repetition frequency Picosecond pulse signal.

Further, described picosecond of optical fiber laser seed source includes sequentially connected saturable absorber SESAM, first Optical fiber collimator, doped gain fiber, reflective wavelength division multiplexer, chirped fiber Bragg grating and the first optoisolator, institute State the driving that picosecond optical fiber laser seed source further includes the first mode pump laser device and the first mode pump laser device Circuit；The saturable absorber SESAM is connected to the doped gain fiber, the reflection through first optical fiber collimator There are two input terminals for formula wavelength division multiplexer tool, are respectively connected to the doped gain fiber and the first mode pump laser device Output end, the output end of the reflective wavelength division multiplexer is connected to the input terminal of the chirped fiber Bragg grating, institute The output end for stating chirped fiber Bragg grating is connected to the input terminal of first optoisolator, first optoisolator Output end is connected to the input terminal of the frequency upgrading part；The reflective wavelength division multiplexer and the chirped fiber Bragg Grating shares one section of tail optical fiber, and the tail optical fiber and the doped gain fiber use short fiber, to shorten picosecond optical-fiber laser The chamber of the resonant cavity of device seed source is long.

Further, the reflective wavelength division multiplexer include sequentially connected second optical fiber collimator, optically filtering piece, Polarizing film and third optical fiber collimator；The input terminal of second optical fiber collimator is connected to the doped gain fiber and described The output end of mode pump laser device；The output end of the third optical fiber collimator is connected to the chirped fiber Bragg grating Input terminal.

Further, the frequency upgrading part includes cascade 50/50 fiber coupler, cascade 50/50 light Fine coupler includes the sequentially connected one 1 × 2nd 50/50 fiber coupler, multiple 2 × 2 50/50 fiber coupler and 21 × 2 50/50 fiber coupler, the multiple 2 × 2 50/50 fiber coupler include 50/50 light of at least three 2 × 2 Fine coupler.

Further, the multiple 2 × 2 50/50 fiber coupler include the one 2 × 2nd 50/50 fiber coupler, 22 × 2nd 50/50 fiber coupler and 50/50 fiber coupler of n-th 2 × 2；Described one 1 × 2nd 50/50 optical fiber Between coupler and the described one 2 × 2nd 50/50 fiber coupler, the described one 2 × 2nd 50/50 fiber coupler and described Between 22 × 2nd 50/50 fiber coupler using optical fiber connect, the described 22 × 2nd 50/50 fiber coupler with it is described Between 50/50 fiber coupler of n-th 2 × 2,50/50 fiber coupler of the n-th 2 × 2 and the described 21 × 2nd It is connected between 50/50 fiber coupler using optical delay line；The frequency upgrading part is using frequency multiplication step by step, for exporting Asia The picosecond pulse laser signal of THz high repetition frequency.

Further, two-stage pre-amplification part includes first order pre-amplification part and second level pre-amplification part, institute State the driving circuit, that first order pre-amplification part includes the second mode pump laser device and the second mode pump laser device The input terminal of one wavelength division multiplexer, the first gain fibre and the second optoisolator, first wavelength division multiplexer is respectively connected to The drive of the output end of the frequency upgrading part and the second mode pump laser device and the second mode pump laser device Dynamic circuit, the output end of first wavelength division multiplexer are connected to second optoisolator by first gain fibre.

Further, second level pre-amplification part includes third mode pump laser device and the third mode pump The driving circuit of laser, the second wavelength division multiplexer, the second gain fibre and third optoisolator, second wavelength division multiplexer Input terminal be respectively connected to the output end and the third mode pump laser device and the third of second optoisolator The output end of the driving circuit of mode pump laser device, second wavelength division multiplexer is connected to by second gain fibre The third optoisolator.

Further, the main amplifier section of the two-stage includes the main amplifier section in the main amplifier section of the first order and the second level, institute Stating the main amplifier section of the first order includes that a pair of first high power multimode pump laser and the first high power multimode pumping swash The driving circuit of light device, (2+1) × 1 combiner device, the first double clad gain fibre and the first high power light isolator, described (2 + 1) × 1 the input terminal of combiner device is respectively connected to the output end of second level pre-amplification part and a pair of described first high The driving circuit of power multimode pump laser and the first high power multimode pump laser, (2+1) × 1 combiner The output end of device is connected to the first high power light isolator by the first double clad gain fibre.

Further, the main amplifier section in the second level includes two group of second high power multimode pump laser and described the The driving circuit of two high power multimode pump lasers, (6+1) × 1 combiner device, the second double clad gain fibre, pumping leakage Device, the second high power light isolator and output end cap, the input terminal of (6+1) × 1 combiner device are respectively connected to described the Second high power multimode pump laser described in the output end of one high power light isolator and two groups and second high power are more The output end of the driving circuit of mould pump laser, (6+1) × 1 combiner device passes through the second double clad gain fibre It is sequentially connected to the pumping leakage device, the second high power light isolator and output end cap.

Further, the leakage of pumping device is for filtering out residual pump light；The end cap be used for output signal light into Row expands, and causes to damage to avoid to fiber end face；The first high power light isolator and second high power light isolation Device is used for the one-way transmission of laser signal.

In the above-mentioned sub- THz high power picosecond optical fiber laser based on MOPA structure, using the picosecond laser of short bore configurations Device seed source generates the picosecond pulse signal of higher repetitive frequency, this signal is passed through the cascade frequency upgrading portion of multi-coupler Point, the high repetition frequency picosecond pulse signal output of Asia THz is realized, using two-stage pre-amplification part and the main amplifier section of two-stage MOPA structure by the high repetition frequency picosecond pulse signal of low-power be amplified to tens watts laser signal export, to obtain The high power picosecond laser signal of sub- THz high repetition frequency.The mounting structure of this method is simple, it is easy to accomplish, it is low in cost, just In popularization.

Detailed description of the invention

Fig. 1 is that the structure of sub- THz high power picosecond optical fiber laser of the utility model embodiment based on MOPA structure is shown It is intended to.

Specific embodiment

The utility model is described in detail below with reference to specific embodiments and the drawings.

Referring to Fig. 1, a kind of sub- THz high power picosecond optical fiber laser 100 based on MOPA structure is shown, including picosecond Optical fiber laser seed source 13, frequency upgrading part 23 and amplifier section, described picosecond of optical fiber laser seed source 13, the frequency It is connected between rate lift portion 23 and the amplifier section by optical fiber；Described picosecond of optical fiber laser seed source 13 is using linear Short bore configurations, the output end of described picosecond of optical fiber laser seed source 13 are connected to the input terminal of the frequency upgrading part 23, The frequency upgrading part 23 is made of cascade 50/50 fiber coupler, the output end connection of the frequency upgrading part 23 To the input terminal of the amplifier section, the amplifier section includes two-stage pre-amplification part 34 and the main amplifier section 47 of two-stage；Institute It states picosecond optical fiber laser seed source 13 and generates high-frequency picosecond pulse signal, signal boost is by the frequency upgrading part 23 The high repetition frequency picosecond pulse signal of sub- THz, then by main amplifier section described in pre-amplification part described in two-stage and two-stage into Row power amplification exports the high power picosecond pulse signal of Asia THz high repetition frequency.

Further, described picosecond of optical fiber laser seed source 13 include sequentially connected saturable absorber SESAM 1, First optical fiber collimator 2, doped gain fiber 3, reflective wavelength division multiplexer 12, chirped fiber Bragg grating 8 and the first light Isolator 9, described picosecond of optical fiber laser seed source 13 further include the first mode pump laser device 11 and first single mode pump The driving circuit 10 of Pu laser 11；The saturable absorber SESAM 1 is connected to described through first optical fiber collimator 2 Doped gain fiber 3, there are two input terminals for the reflective tool of wavelength division multiplexer 12, are respectively connected to the doped gain fiber 3 and the first mode pump laser device 11 output end, the output end of the reflective wavelength division multiplexer 12 is connected to described The input terminal of chirped fiber Bragg grating 8, the output end of the chirped fiber Bragg grating 8 be connected to first light every Input terminal from device 9, the output end of first optoisolator 9 are connected to the input terminal of the frequency upgrading part 23；It is described Reflective wavelength division multiplexer 12 shares one section of tail optical fiber with the chirped fiber Bragg grating 8, and the tail optical fiber and the doping increase Beneficial optical fiber 3 uses short fiber, long to shorten the chamber of resonant cavity of picosecond optical fiber laser seed source 13.

Further, the reflective wavelength division multiplexer 12 includes sequentially connected second optical fiber collimator 4, optically filtering Piece 5, polarizing film 6 and third optical fiber collimator 7；The input terminal of second optical fiber collimator 4 is connected to the doping gain light The output end of fibre 3 and the mode pump laser device；The output end of the third optical fiber collimator 7 is connected to the chirped fiber The input terminal of Bragg grating 8.

Specifically, the output of the chirped fiber Bragg grating 8 in described picosecond of optical fiber laser seed source 13 is saturating The adjusting of institute, percentage section is penetrated, to realize the adjusting to output power, but the output percentage of the chirped fiber Bragg grating 8 It need to cooperate with the length of the doped gain fiber 3.The chirped fiber Bragg grating 8 can be with color in effective compensation resonant cavity It dissipates, to realize relatively narrow picosecond pulse laser signal output, and efficiently controls the center for exporting laser by its filter action The spectral bandwidth of wavelength and mode-locked laser reduces noise.

Specifically, the chirped fiber Bragg grating 8 effectively compensates for picosecond optical fiber laser seed source 13 Dispersion in resonant cavity obtains picosecond pulse signal；The bandwidth width of the chirped fiber Bragg grating 8 can control and participate in The spectral width of mode locking inhibits other wavelength noises, improves system stability；8 part of chirped fiber Bragg grating is saturating It penetrates and can be used as output coupling mirror.

Specifically, first optical fiber collimator 2 carried out optical fiberization encapsulation, first optical fiber collimator 2 with it is described Saturable absorber SESAM 1 carries out modularized encapsulation, effectively reduces system space size.

Preferably, the doped gain fiber 3 uses Yb-doped fiber, can also use other doped fibers, select highly doped The gain fibre of miscellaneous concentration can get high-output power, can also reduce gain fibre length, but gain fibre length need to it is intracavitary Dispersion, non-linear, decaying match, to obtain the picosecond pulse output of optimization.

Specifically, described picosecond of optical fiber laser seed source 13 carries out mode locking using the saturable absorber SESAM 1, Using its non-linear saturated absorption characteristic can passive mode-locking short cavity optical fiber laser, obtain high repeat frequency pulsed laser output. In order to radiate to the saturable absorber SESAM 1, the heat sink materials such as copper product or aluminium can be used as its pedestal.

Specifically, each component of described picosecond of optical fiber laser seed source 13 is polarization-maintaining component, to ensure to be System energy stable operation, and realize that short cavity has the Low threshold mode locking Picopulse optical fiber laser of self-starting performance.

Further, the frequency upgrading part 23 include cascade 50/50 fiber coupler, described cascade 50/50 Fiber coupler includes the sequentially connected one 1 × 2nd 50/50 fiber coupler 14, multiple 2 × 2 50/50 fiber coupler 15, the 16,17,18 and the 21 × 2nd 50/50 fiber coupler 19, the multiple 2 × 2 50/50 fiber coupler include extremely Few 32 × 2 50/50 fiber couplers include the 50/50 of the one 2 × 2nd 50/50 fiber coupler the 15, the 22 × 2nd 50/50 fiber coupler 18 of fiber coupler 16 and n-th 2 × 2；Described one 1 × 2nd 50/50 fiber coupler, 14 He Between described one 2 × 2nd 50/50 fiber coupler 15, the described one 2 × 2nd 50/50 fiber coupler 15 and described second It is connected between 2 × 2 50/50 fiber coupler 16 using optical fiber 20,21, the described 22 × 2nd 50/50 fiber coupler 16 Between 50/50 fiber coupler 18 of the n-th 2 × 2,50/50 fiber coupler 18 of the n-th 2 × 2 and described It is connected between 21 × 2nd 50/50 fiber coupler 19 using optical delay line 22；The frequency upgrading part 23 using by Grade frequency multiplication, for exporting the picosecond pulse laser signal of sub- THz high repetition frequency.

Specifically, the frequency upgrading part 23 is cascaded by multiple 50/50 couplers, described picosecond of optical-fiber laser 50/50 coupler of the laser signal that device seed source 13 exports into a 1x2 are divided into two-way light, and two of first order coupler Output end is connected to two input terminals of next stage coupler, and the arm length difference of the two ports is matched with the repetition rate of input, Subsequent every grade of coupler all has the arm length difference to match with the repetition rate for entering its own.Preferably, entering frequency What higher last coupler provides the delay of pulse using the optical delay line, to obtain Asia THz high repetition frequency Picosecond pulse laser.

Specifically, the input terminal of what preceding coupler of the frequency upgrading part 23 uses ordinary optic fibre, needs basis The length of optical fiber is determined into the picosecond pulse repetition rate of corresponding stage fiber coupler, to make the arm of this grade of fiber coupler Long difference and the repetition rate of pulse signal match.With the promotion of frequency, the repetition rate into coupler is higher and higher, with This corresponding fiber lengths is also shorter and shorter, and when sub- THz repetition rate, the length of optical fiber is reached or fallen below grade Not, it is difficult to be accurately controlled the arm length difference of fiber coupler, therefore what uses its arm length difference of optical delay line traffic control later, Realize the picosecond pulse output of more high repetition frequency.

The lift portion is in the very high situation of optical fiber laser pulse repetition frequency, using optical delay line Pulse delay signal is carried out to pulse, if picosecond very narrow such as femtosecond pulse of the pulse of optical fiber laser seed source 13 itself is believed Number, it can be achieved that the high repetition frequency of THz output of pulse signal.

Further, two-stage pre-amplification part 34 includes first order pre-amplification part and second level pre-amplification part, First order pre-amplification part includes the driving of the second mode pump laser device 24 and the second mode pump laser device 24 Circuit 25, the first wavelength division multiplexer 26, the first gain fibre 27 and the second optoisolator 28, first wavelength division multiplexer 26 Input terminal is respectively connected to the output end and the second mode pump laser device 24 and described of the frequency upgrading part 23 The output end of the driving circuit 25 of two mode pump laser devices 24, first wavelength division multiplexer 26 passes through the first gain light Fibre 27 is connected to second optoisolator 28.Second level pre-amplification part includes third mode pump laser device 29 and institute State driving circuit 30, the second wavelength division multiplexer 31, the second gain fibre 32 and the third light of third mode pump laser device 29 every From device 33, the input terminal of second wavelength division multiplexer 31 is respectively connected to the output end of second optoisolator 28 and described The driving circuit 30 of third mode pump laser device 29 and the third mode pump laser device 29, second wavelength division multiplexer 31 output end is connected to the third optoisolator 33 by second gain fibre 32.

Specifically, two-stage pre-amplification part 34 includes mode pump laser device and the mode pump laser device Driving circuit, gain fibre, low-power optoisolator and wavelength division multiplexer, can be by power amplification to hundred milliwatt magnitudes.It will be described Pre-amplification part is divided into two-stage pre-amplification part 34, can effectively inhibit the spontaneous radiation of amplification, dispersion and non-linear to arteries and veins The influence of signal is rushed, but needs to carry out the parameters such as the pump power of mode pump laser device, the length of gain fibre and concentration Control.Low-power optoisolator can inhibit backward spontaneous radiation amplification, improve quality of output signals.

Two-stage pre-amplification structure can effectively reduce ASE noise and inhibit non-linear effectiveness, while can also mention Enter main amplifier section for enough pulse lights；Second optoisolator 28 and the third optoisolator 33 are effectively Backward spontaneous radiation is inhibited to amplify.

Further, the main amplifier section 47 of the two-stage includes the main amplifier section in the main amplifier section of the first order and the second level, The main amplifier section of the first order includes a pair of first high power multimode pump laser and the first high power multimode pumping Driving circuit 35 and 36, (2+1) × 1 combiner device 37, the first double clad gain fibre 38 and the first high power light of laser The input terminal of isolator 39, (2+1) × 1 combiner device 37 is respectively connected to the output end of second level pre-amplification part With the driving circuit 35 of a pair of first high power multimode pump laser and the first high power multimode pump laser With 36, the output end of (2+1) × 1 combiner device 37 is connected to described first by the first double clad gain fibre 38 High power light isolator 39.The main amplifier section in the second level includes two group of second high power multimode pump laser and described the Driving circuit 40 and 41, (6+1) × 1 combiner device 42, the second double clad gain fibre of two high power multimode pump lasers 43, pumping leakage device 44, the second high power light isolator 45 and output end cap 46, the input of (6+1) × 1 combiner device 42 Hold the second high power multimode pumping laser described in the output end for being respectively connected to the first high power light isolator 39 and two groups The driving circuit 40 and 41 of device and the second high power multimode pump laser, the output of (6+1) × 1 combiner device 42 End is sequentially connected to the pumping by the second double clad gain fibre 43 and reveals device 44, the second high power light isolator 45 With output end cap 46.

Specifically, described (2+1) × 1 combiner device 37 and (6+1) × 1 optical-fiber bundling device 42 are by multimode pumping laser The pump light branch of device is coupled into the first double clad gain fibre 38 and the second double clad gain fibre 43, makes Doped ions transition, thus amplified signal light.High power light isolator can efficiently control backward spontaneous radiation amplification, change Kind quality of output signals.

Specifically, it is imitated using the spontaneous radiation that stimulated raman scattering and amplification can be effectively suppressed in the main enlarged structure of two-stage With realizing the output of high-power pulsed laser signal；The first double clad gain fibre 38 and the second double clad gain Powerful pump light is coupled into optical fiber by optical fiber 43 by covering.

The high power multimode pump laser of the main amplifier section 47 of two-stage is swashed using the multiple die semiconductor of 976nm wavelength Light device can effectively shorten the length of double clad gain fibre since this wavelength absorption is high-efficient, to reduce nonlinear effect Influence to output pulse.

Further, the leakage of pumping device 44 is for filtering out residual pump light；The end cap 46 is used for output signal Light is expanded, and causes to damage to avoid to fiber end face；The first high power light isolator 39 and second high power Optoisolator 45 is used for the one-way transmission of laser signal.

Specifically, the leakage of pumping device 44 of the main amplifier section 47 of the two-stage can filter out superfluous pump light, eliminate Its influence to output signal light；Increase the coupling of end cap 46 output at output optical fibre end, high power damage can be prevented defeated The end face of optical fiber out；The spontaneous radiation of amplification can be effectively suppressed in high power isolator, reduces its influence to output signal light.

Preferably, described picosecond of optical fiber laser seed source 13 uses short oscillation cavity structure, improves seed source pulsed light The repetition rate of fibre laser output pulse signal effectively reduces 50/50 coupling used in the frequency upgrading part 23 The series of clutch, therefore simplify the structure of entire high repetition frequency high power picosecond optical fiber laser 100.

The utility model has the advantage that one, the utility model connects wavelength division multiplexer by one section short gain fibre One end and collimator one end, one section of short-tail fibre connection wavelength division multiplexer other end and chirped fiber Bragg grating 8, thus effectively It is long to reduce laser resonant cavity chamber.Two, the utility model picosecond optical fiber laser seed source 13 is long using short oscillation cavity chamber, can subtract Lack the series of cascade coupler and there is preferable stability.Three, the utility model is when repetition rate reaches higher level The delay of pulse is provided using optical delay line, to obtain the output of more high repeat frequency pulsed laser.Four, the utility model is adopted With the MOPA structure of preposition two-stage pre-amplification and the main amplification of two-stage, high power is realized in the effect that can preferably control nonlinear characteristic Pulse laser output.Five, the component all-fiber encapsulation of the utility model, whole system is compact, reduces insertion loss, increases The reliability of system is added.

In the above-mentioned sub- THz high power picosecond optical fiber laser 100 based on MOPA structure, using short bore configurations picosecond swash Light device seed source generates the picosecond pulse signal of higher repetitive frequency, this signal is passed through the cascade frequency upgrading of multi-coupler Part 23 is realized the high repetition frequency picosecond pulse signal output of Asia THz, is put using two-stage pre-amplification part 34 and two-stage master Most of 47 MOPA structure exports the laser signal that the high repetition frequency picosecond pulse signal of low-power is amplified to tens watts, To obtain the high power picosecond laser signal of sub- THz high repetition frequency.The mounting structure of this method is simple, it is easy to accomplish, at This is cheap, convenient for promoting.

It should be noted that the utility model is not limited to above embodiment, creation essence according to the present utility model Mind, those skilled in the art can also make other variations, these variations done according to the creative spirit of the utility model, all Should be included in the utility model it is claimed within the scope of.

Claims (10)

1. a kind of sub- THz high power picosecond optical fiber laser based on MOPA structure, which is characterized in that including a picosecond optical-fiber laser Device seed source, frequency upgrading part and amplifier section, described picosecond of optical fiber laser seed source, the frequency upgrading part and institute It states and is connected between amplifier section by optical fiber；Described picosecond of optical fiber laser seed source uses linear short bore configurations, and described picosecond The output end of optical fiber laser seed source is connected to the input terminal of the frequency upgrading part, and the frequency upgrading part is by cascading 50/50 fiber coupler composition, the output end of the frequency upgrading part is connected to the input terminal of the amplifier section, described Amplifier section includes two-stage pre-amplification part and the main amplifier section of two-stage；Described picosecond of optical fiber laser seed source generates high repeat Frequency picosecond pulse signal, the high repetition frequency picosecond pulse signal that signal boost is Asia THz by the frequency upgrading part, then Power amplification is carried out by main amplifier section described in pre-amplification part described in two-stage and two-stage, output Asia THz high repetition frequency High power picosecond pulse signal.

2. the sub- THz high power picosecond optical fiber laser based on MOPA structure as described in claim 1, which is characterized in that institute Stating a picosecond optical fiber laser seed source includes sequentially connected saturable absorber SESAM, the first optical fiber collimator, doping gain Optical fiber, reflective wavelength division multiplexer, chirped fiber Bragg grating and the first optoisolator, described picosecond of optical fiber laser seed Source further includes the driving circuit of the first mode pump laser device and the first mode pump laser device；The saturable absorber SESAM is connected to the doped gain fiber through first optical fiber collimator, and there are two the reflective wavelength division multiplexer tools Input terminal is respectively connected to the output end of the doped gain fiber and the first mode pump laser device, described reflective The output end of wavelength division multiplexer is connected to the input terminal of the chirped fiber Bragg grating, the chirped fiber Bragg grating Output end be connected to the input terminal of first optoisolator, the output end of first optoisolator is connected to the frequency The input terminal of lift portion；The reflective wavelength division multiplexer and the chirped fiber Bragg grating share one section of tail optical fiber, institute Tail optical fiber and the doped gain fiber are stated using short fiber, to shorten the chamber of the resonant cavity of picosecond optical fiber laser seed source It is long.

3. the sub- THz high power picosecond optical fiber laser based on MOPA structure as claimed in claim 2, which is characterized in that institute Stating reflective wavelength division multiplexer includes that sequentially connected second optical fiber collimator, optically filtering piece, polarizing film and third optical fiber are quasi- Straight device；The input terminal of second optical fiber collimator is connected to the defeated of the doped gain fiber and the mode pump laser device Outlet；The output end of the third optical fiber collimator is connected to the input terminal of the chirped fiber Bragg grating.

4. the sub- THz high power picosecond optical fiber laser based on MOPA structure as described in claim 1, which is characterized in that institute Stating frequency upgrading part includes cascade 50/50 fiber coupler, and cascade 50/50 fiber coupler includes being sequentially connected The one 1 × 2nd 50/50 fiber coupler, multiple 2 × 2 50/50 fiber coupler and the 21 × 2nd 50/50 optical fiber coupling Clutch, the multiple 2 × 2 50/50 fiber coupler include 50/50 fiber coupler of at least three 2 × 2.

5. the sub- THz high power picosecond optical fiber laser based on MOPA structure as claimed in claim 4, which is characterized in that institute 50/50 fiber coupler for stating multiple 2 × 2 includes the one 2 × 2nd 50/50 fiber coupler, the 22 × 2nd 50/50 optical fiber 50/50 fiber coupler of coupler and n-th 2 × 2；Described one 1 × 2nd 50/50 fiber coupler and described 1st × Between 2 50/50 fiber coupler, the one 2 × 2nd 50/50 fiber coupler and the described 22 × 2nd 50/50 optical fiber It is connected between coupler using optical fiber, 50/50 light of the described 22 × 2nd 50/50 fiber coupler and the n-th 2 × 2 Between fine coupler, 50/50 fiber coupler of the n-th 2 × 2 and the described 21 × 2nd 50/50 fiber coupler it Between using optical delay line connect；The frequency upgrading part is using frequency multiplication step by step, for exporting the skin of sub- THz high repetition frequency Pulse per second (PPS) laser signal.

6. the sub- THz high power picosecond optical fiber laser based on MOPA structure as described in claim 1, which is characterized in that institute Stating two-stage pre-amplification part includes first order pre-amplification part and second level pre-amplification part, first order pre-amplification part packet Include the driving circuit, the first wavelength division multiplexer, the first increasing of the second mode pump laser device and the second mode pump laser device Beneficial optical fiber and the second optoisolator, the input terminal of first wavelength division multiplexer are respectively connected to the defeated of the frequency upgrading part The driving circuit of outlet and the second mode pump laser device and the second mode pump laser device, first wavelength-division are multiple Second optoisolator is connected to by first gain fibre with the output end of device.

7. the sub- THz high power picosecond optical fiber laser based on MOPA structure as claimed in claim 6, which is characterized in that institute State the driving circuit, that second level pre-amplification part includes third mode pump laser device and the third mode pump laser device The input terminal of two wavelength division multiplexers, the second gain fibre and third optoisolator, second wavelength division multiplexer is respectively connected to The drive of the output end of second optoisolator and the third mode pump laser device and the third mode pump laser device Dynamic circuit, the output end of second wavelength division multiplexer are connected to the third optoisolator by second gain fibre.

8. the sub- THz high power picosecond optical fiber laser based on MOPA structure as claimed in claim 6, which is characterized in that institute Stating the main amplifier section of two-stage includes the main amplifier section in the main amplifier section of the first order and the second level, the main enlarging section subpackage of the first order Include driving circuit, (2+1) of a pair of first high power multimode pump laser and the first high power multimode pump laser × 1 combiner device, the first double clad gain fibre and the first high power light isolator, the input of (2+1) × 1 combiner device End be respectively connected to second level pre-amplification part output end and a pair of first high power multimode pump laser and The driving circuit of the first high power multimode pump laser, the output end of (2+1) × 1 combiner device pass through described the A pair of cladding gain optical fiber is connected to the first high power light isolator.

9. the sub- THz high power picosecond optical fiber laser based on MOPA structure as claimed in claim 8, which is characterized in that institute Stating the main amplifier section in the second level includes that two group of second high power multimode pump laser and the second high power multimode pumping swash The driving circuit of light device, (6+1) × 1 combiner device, the second double clad gain fibre, pumping leakage device, the second high power light every From device and output end cap, the input terminal of (6+1) × 1 combiner device is respectively connected to the first high power light isolator The driving of second high power multimode pump laser and the second high power multimode pump laser described in output end and two groups The output end of circuit, (6+1) × 1 combiner device is sequentially connected to the pumping by the second double clad gain fibre Reveal device, the second high power light isolator and output end cap.

10. the sub- THz high power picosecond optical fiber laser based on MOPA structure as claimed in claim 9, which is characterized in that institute Leakage of pumping device is stated for filtering out residual pump light；The end cap is for expanding output signal light, to avoid to optical fiber It causes to damage in end face；The first high power light isolator and the second high power light isolator are for the unidirectional of laser signal Transmission.