CN204190774U - A kind of optical triangulation shape pulse generator based on four times of rf modulations - Google Patents

Abstract

A kind of optical triangulation shape pulse generator based on four times of rf modulations, relate to opto-electronic device, Microwave photonics, all-optical data process field, continuous-wave laser (1) first connects Polarization Controller (2), Polarization Controller (2) connects two parallel MZ Mach-Zehnder (3) subsequently, sinusoidal wave local oscillator (4) connects 90 degree of electric bridges (5), the driving port that 90 degree of electric bridges (5) connect two parallel Mach zehnder modulators (3) makes it work in push-pull mode, bias voltage source (6) connects two parallel Mach zehnder modulators (3), for it provides bias voltage, two parallel Mach zehnder modulators (3) connects erbium-doped fiber amplifier (7) and band pass filter (8) subsequently, signal is amplified and filtering, band pass filter (8) connect circulator (9), another input port of circulator (9) connects chirped fiber Bragg gratings (10), the triangle light pulse of output can be received from the output port of circulator.

Description

A kind of optical triangulation shape pulse generator based on four times of rf modulations

Technical field

The present invention relates to opto-electronic device, Microwave photonics, all-optical data process field, specifically a kind of optical triangulation shape pulse generator based on four times of rf modulations.

Background technology

All-optical signal processing technology is the important component part of all-optical communication network, is the emphasis of research both at home and abroad at present.In all-optical signal processing, periodic triangular shape optical pulse train is a kind of periodicity and in time domain scale, has the special optical pulse train of linear rising edge and trailing edge, and it generates and other key technologies are widely studied.The pulse of optical triangulation shape can be used for all-optical data process.Such as, utilize the time domain specification of triangle light pulse, in conjunction with optical non-linear effect, triangle light pulse can realize efficient All Optical Wavelength Conversion.The pulse of optical triangulation shape, in conjunction with Cross-phase Modulation (XPM), can convert complete for time division multiplexing (TDM) light to wavelength division multiplexing (WDM) signal.In addition, light signal time domain and frequency domain copy, pulse compression can be realized by the propagation in the Cross-phase Modulation of triangle pump pulses generation and dispersive medium being combined.Therefore, photon triangle generator is considered to following all-optical network very important equipment.

In recent years, the achievement in research of a series of triangle light pulse photon generator is in succession reported in the world.All-optical pulse shaping using mode-locked laser as light source obtains the most popular method that symmetrical triangle light pulse adopts at present.Such as, 2011, the people such as the J.Ye of Southwest Jiaotong University mention one and utilize polarization maintaining optical fibre, Polarization Controller and the polarizer as spectral shaping unit in the achievement in research that they are nearest, and in conjunction with FTTM, triangle light pulse (Ye J can be obtained, Yan L, Pan W, et al.Photonic generation oftriangular-shaped pulses based on frequency-to-time conversion [J] .Optics letters.2011,36 (8): 1458-1460.).2013, people's research and utilizations such as A.Zhang three groups of grating array are as spectral shaping unit, the generation of random waveform can be realized in conjunction with FTTM, comprise symmetrical triangle light pulse (A.Zhang and C.Li, Analysis of dynamic optical arbitrary waveform generation basedon three FBG arrays [J] .Optics & Laser Technology, 2013, vol.52, pp.81-86.).In addition to the above methods, also continuous-wave laser can be obtained symmetrical triangle light pulse as light source.Such as, the people such as B.Dai utilize and carry out to continuous light the comb spectrum that rf modulations produces similar pulse laser, the amplitude of produced each spectral line of comb spectrum and phase place are adjusted, generation comprises symmetrical triangle, zigzag, pulse (the B.Dai of the multiple time-domain shape such as flat-top shape and sinusoid, Z.Gao, X.Wang, et al.Generation ofVersatile Waveforms From CW Light Using a Dual-Drive Mach-Zehnder Modulatorand Employing Chromatic Dispersion [J] .IEEE/OSA Journal of LightwaveTechnology, 2013, vol.31, pp.145-151.).In addition, the people such as J.Li also proposed the mode with harmonious wave fitting, utilize the radio-frequency power fading effect caused by continuous wave rf modulations and optical fiber dispersion, obtain the method (J.Li of periodic undulations symmetrical triangle optical pulse train, X.Zhang, B.Hraimel, et al.PerformanceAnalysis of a Photonic-Assisted Periodic Triangular-Shaped Pulses Generator [J] .IEEE/OSA Journal of Lightwave Technology, 2012, vol.30, pp.1617-1624.).But, the above-mentioned spectral shaping method using mode-locked laser as light source, scheme needs stable Mode-locked laser device, and price is very expensive; The above-mentioned triangle optical pulse generator using continuous-wave laser as light source, fiber lengths scope is fixed, system underaction, and repetition rate is not high enough.For this reason, design a kind of structure simple, low price, can save fibre that long range propagation depletes, and generates the generator with the optical triangulation pulse in higher repetition rate or less pulse duration and is very important.

Summary of the invention

The present invention is to provide the low a kind of optical triangulation shape pulse generator based on four times of rf modulations of cost.Different from traditional generation method, this device take continuous-wave laser as light source, when utilizing two parallel Mach zehnder modulators to work in maximum transmitted point, maximum transmitted point, minimum transfer point respectively, output optical signal is similar to impulse form, utilize strength retrogression's effect caused by the dispersion in chirped fiber Bragg gratings subsequently, shaping is carried out to light pulse, the parameter of adjusting device, obtain the triangle light pulse with high repetition frequency.Owing to using four times of rf modulations, because the operating frequency of current modulator can reach 40GHz, this device can produce the light pulse of repetition rate 160GHz triangle.This device only adopts cheap continuous-wave laser to be light source, thus greatly must reduce costs; Adopt grating, save the Optical Fiber Transmission of long distance; And consider that bias point drifts about, make this device have very high commercial value.

Technical scheme of the present invention: a kind of optical triangulation shape pulse generator based on four times of rf modulations, it is characterized in that: this triangle generator comprises, continuous-wave laser, Polarization Controller, two parallel MZ Mach-Zehnder, sinusoidal wave local oscillator, 90 ° of electric bridges, bias voltage source, erbium-doped fiber amplifier, band pass filter, circulator, chirped fiber Bragg gratings; Concrete connected mode is:

The input of the light output termination Polarization Controller of continuous-wave laser, the light input end of the two parallel MZ Mach-Zehnder of output termination of Polarization Controller, the electricity of sinusoidal wave local oscillator exports the electrical input of termination 90 degree of electric bridges, 90 degree of electric output ports and 0 degree of electric output port of 90 degree of electric bridges connect the first electric drive port and the second electric drive port of two parallel Mach zehnder modulators respectively, the electricity of bias voltage source exports the voltage bias port of the two parallel Mach zehnder modulators of termination, the light input end of the light output termination erbium-doped fiber amplifier of two parallel Mach zehnder modulators, the input of the light output end tape splicing bandpass filter of erbium-doped fiber amplifier, the output of band pass filter connects the input of circulator, first of circulator exports the input of termination chirped fiber Bragg gratings, second output of circulator exports triangle light pulse.

Regulate the output voltage V of bias voltage source _bias, make V _bias=V _π, wherein V _πfor the half-wave changing voltage of two parallel Mach zehnder modulators, and 2V≤V _π≤ 4V.Two sub-MZ and female MZ of two parallel Mach zehnder modulators are offset to maximum transmitted point, maximum transmitted point, minimum transfer point respectively;

The setting index of modulation=π V _rF/ 2V _π=4.438, regulate the sinusoidal signal amplitude V that sinusoidal wave local oscillator exports _rF=2.825V _π;

Regulate the total dispersion amount DL of chirped fiber Bragg gratings, meet wherein c is the propagation velocity of light in vacuum, f _rFfor the output sinusoidal signal of sinusoidal wave local oscillator, its frequency is 1GHz≤f _rF≤ 40GHz;

The bias voltage source offset Δ V of two parallel MZ Mach-Zehnder _bias, its scope is-0.5%≤Δ V _bias≤ 1%;

Through above-mentioned setting, circulator exports as triangle light pulse, and repetition rate is f=4f _rF.

Specific works principle of the present invention is as follows:

The optical electric field expression formula exported by continuous-wave laser is:

E _in(t)＝E ₀exp(jω ₀) (1)

Wherein E ₀for optical signal magnitude, ω ₀centered by angular frequency, then light signal is input to two parallel MZ Mach-Zehnder, when the extinction ratio of DP-MZM is ε through polarizer _rduring=∞, the optical field distribution of DP-MZM output is

$\begin{array}{c}E\left(t\right)=\frac{E_{\mathrm{in}}\left(t\right)}{2}\left\{\exp \right[j\frac{V_{\mathrm{RF}}}{2V_{\mathrm{\π}}}\cos \left({\mathrm{\ω}}_{\mathrm{RF}}t\right)]+\exp [-j\frac{V_{\mathrm{RF}}}{2V_{\mathrm{\π}}}\cos \left({\mathrm{\ω}}_{\mathrm{RF}}t\right)]-\exp [-j\frac{V_{\mathrm{RF}}}{2V_{\mathrm{\π}}}\sin \left({\mathrm{\ω}}_{\mathrm{RF}}t\right)]-\\ \exp [+j\frac{V_{\mathrm{RF}}}{2V_{\mathrm{\π}}}\sin \left({\mathrm{\ω}}_{\mathrm{RF}}t\right)]=\frac{E_{\mathrm{in}}\left(t\right)}{2}{\mathrm{\Σ}}_{k=-\∞}^{\∞}{a}_{4k-2}\exp [j(4k-2){\mathrm{\ω}}_{\mathrm{RF}}t\end{array}---\left(2\right)$

Wherein, a _4k-2=[j ^4k+2+ j ^4k-2(-1) ^4k-2-(-1) ^4k-2-1] J _4K-2(m), V _πrepresent the half-wave changing voltage of DP-MZM.It is V that local radio-frequency oscillator exports radiofrequency signal expression formula _rF(t)=V _rFcos (ω _rFt), wherein V _rFand ω _rF=2 π f _rFrepresent RF signal amplitude and angular frequency respectively.

Known m=π V _rF/ 2V _π, as seen from the figure as m=4.438, have J ₂(m) ≈ 3J ₆(m).Can find that 10 subharmonic are very little, can be left in the basket.Now, in distribution of light intensity, the component of RF only has 4 times, 8 times and 12 subharmonic.Scheme utilizes chirped fiber Bragg grating to simulate Characteristics of Single-mode Optical Fibers to eliminate unwanted 8 subharmonic (cos (ω _rFt)), then grating dispersion amount need meet:

$\mathrm{DL}=\left(\frac{2n+1}{2}\right)\frac{{\mathrm{c\π}}^2}{8{\mathrm{\ω}}_{\mathrm{RF}}^2{{\mathrm{\λ}}_0}^2},n=\mathrm{0,1,2},......\left(3\right)$

Wherein λ ₀centered by wavelength, c is light propagation velocity in a vacuum.Now, output distribution of light intensity is:

$I_{\mathrm{out}}\left(t\right)\∝\cos \left(4{\mathrm{\ω}}_{\mathrm{RF}}t\right)+\frac{J_6^2\left(m\right)}{J_2^2\left(m\right)}\cos \left(12{\mathrm{\ω}}_{\mathrm{RF}}t\right)---\left(4\right)$

The Fourier expansion formula of ideal triangular waveform:

$T\left(t\right)\∝\cos \left(\mathrm{\Ωt}\right)+\frac{1}{9}\cos \left(3\mathrm{\Ωt}\right)+\frac{1}{25}\cos \left(5\mathrm{\Ωt}\right)+...\left(5\right)$

Now, for given modulation parameter m=4.438, in (4) formula suppose Ω=4 ω _rF.

Because the existence of finite extinction ratio, the impact that ± 1, ± 3, ± 5, ± 7 odd rank sidebands bring must be considered.This impact can minimize by suitably adjusting grating dispersion coefficient n.And as n=5, be the best.Now, after modulator, access erbium-doped fiber amplifier, light pulse signal is amplified, and access band pass filter filtering is carried out to unwanted noise sideband.The triangular waveform produced is in close proximity to ideal triangular waveform, and reference diagram (2) is depicted as triangular waveform and compares schematic diagram, and solid line is I _outt (), dotted line is T (t), and both waveforms visible are very approximate, and difference can be ignored, and this illustrates and utilizes front two order harmonics matchings can the temporal signatures of approximate representation symmetrical triangle.Visible device is definitely feasible from principle.

Beneficial effect of the present invention is specific as follows:

The present invention does not relate to complicated structure, make full use of electrooptic modulation principle, create the triangular wave of high repetition frequency with photonic propulsion method, and scheme adopts cheap continuous-wave laser, and replace general single mode fiber with fiber grating, acquisition cost can be reduced greatly.

Accompanying drawing explanation

A kind of triangle optical pulse generator schematic diagram based on four times of rf modulations of Fig. 1.

Fig. 2 triangular waveform compares schematic diagram

The triangular wave time domain waveform schematic diagram (frequency f=1GHz) that Fig. 3 triangle optical pulse generator produces.

The triangular wave time domain waveform schematic diagram (frequency f=10GHz) that Fig. 4 triangle optical pulse generator produces.

The triangular wave time domain waveform schematic diagram (frequency f=20GHz) that Fig. 5 triangle optical pulse generator produces.

The triangular wave time domain waveform schematic diagram (frequency f=30GHz) that Fig. 6 triangle optical pulse generator produces.

The triangular wave time domain waveform schematic diagram (frequency f=40GHz) that Fig. 7 triangle optical pulse generator produces.

Embodiment

Below in conjunction with accompanying drawing 1 to 7, a kind of triangle optical pulse generator based on four times of rf modulations is further described.

Embodiment one

A kind of triangle optical pulse generator based on four times of rf modulations, as shown in Figure 1, it is characterized in that: this triangle generator comprises, continuous-wave laser 1, Polarization Controller 2, two parallel MZ Mach-Zehnder 3, sinusoidal wave local oscillator 4,90 ° of electric bridges 5, bias voltage source 6, erbium-doped fiber amplifier 7, band pass filter 8, circulator 9, chirped fiber Bragg gratings 10; Concrete connected mode is:

The input of the light output termination Polarization Controller 2 of continuous-wave laser 1, the light input end of the two parallel MZ Mach-Zehnder 3 of output termination of Polarization Controller 2, the electricity of sinusoidal wave local oscillator 4 exports the electrical input of termination 90 degree of electric bridges 5, 90 degree of electric output ports 51 and 0 degree of electric output port 52 of 90 degree of electric bridges 5 connect the first electric drive port 31 and the second electric drive port 32 of two parallel Mach zehnder modulators 3 respectively, the electricity of bias voltage source 6 exports the voltage bias port 33 of the two parallel Mach zehnder modulators 3 of termination, the light input end of the light output termination erbium-doped fiber amplifier 7 of two parallel Mach zehnder modulators 3, the input of the light output end tape splicing bandpass filter 8 of erbium-doped fiber amplifier 7, the output of band pass filter 8 connects the input 91 of circulator 9, first output 92 of circulator 9 connects the input of chirped fiber Bragg gratings 10, second output 93 of circulator exports triangle light pulse.

Regulate the output voltage V of bias voltage source 6 _bias, make V _bias=V _π=2V, wherein V _πfor the half-wave changing voltage of two parallel Mach zehnder modulators 3.Two sub-MZ and female MZ of two parallel Mach zehnder modulators 3 are offset to maximum transmitted point, maximum transmitted point, minimum transfer point respectively;

The setting index of modulation=π V _rF/ 2V _π=4.438, regulate the sinusoidal signal amplitude V that sinusoidal wave local oscillator 4 exports _rF=2.825V _π=5.65V, wherein V _π=2V is the half-wave changing voltage of two parallel Mach zehnder modulators 3;

Regulate the total dispersion amount DL of chirped fiber Bragg gratings 9, meet wherein c is the propagation velocity of light in vacuum, f _rF=1GHz is the output sinusoidal signal of sinusoidal wave local oscillator 4;

The bias voltage source offset Δ V of two parallel MZ Mach-Zehnder 3 _bias=0.5%;

The present embodiment ε _rvalue is 25dB, Δ V _biasvalue is 0.5%, f _rF=1GHz, V _π=2V, after above-mentioned adjustment, fiber grating 9 exports as triangle light pulse, and repetition rate is f=4f _rF=4GHz, shown in corresponding time-domain curve Fig. 3.

Embodiment two

A kind of triangle optical pulse generator based on four times of rf modulations, as shown in Figure 1, it is characterized in that: this triangle generator comprises, continuous-wave laser 1, Polarization Controller 2, two parallel MZ Mach-Zehnder 3, sinusoidal wave local oscillator 4,90 ° of electric bridges 5, bias voltage source 6, erbium-doped fiber amplifier 7, band pass filter 8, circulator 9, chirped fiber Bragg gratings 10; Concrete connected mode is:

The input of the light output termination Polarization Controller 2 of continuous-wave laser 1, the light input end of the two parallel MZ Mach-Zehnder 3 of output termination of Polarization Controller 2, the electricity of sinusoidal wave local oscillator 4 exports the electrical input of termination 90 degree of electric bridges 5, 90 degree of electric output ports 51 and 0 degree of electric output port 52 of 90 degree of electric bridges 5 connect the first electric drive port 31 and the second electric drive port 32 of two parallel Mach zehnder modulators 3 respectively, the electricity of bias voltage source 6 exports the voltage bias port 33 of the two parallel Mach zehnder modulators 3 of termination, the light input end of the light output termination erbium-doped fiber amplifier 7 of two parallel Mach zehnder modulators 3, the input of the light output end tape splicing bandpass filter 8 of erbium-doped fiber amplifier 7, the output of band pass filter 8 connects the input 91 of circulator 9, first output 92 of circulator 9 connects the input of chirped fiber Bragg gratings 10, second output 93 of circulator exports triangle light pulse.

Regulate the output voltage V of bias voltage source 6 _bias, make V _bias=V _π=2V, wherein V _πfor the half-wave changing voltage of two parallel Mach zehnder modulators 3.Two sub-MZ and female MZ of two parallel Mach zehnder modulators 3 are offset to maximum transmitted point, maximum transmitted point, minimum transfer point respectively;

The setting index of modulation=π V _rF/ 2V _π=4.438, regulate the sinusoidal signal amplitude V that sinusoidal wave local oscillator 4 exports _rF=2.825V _π=5.65V, wherein V _π=2V is the half-wave changing voltage of two parallel Mach zehnder modulators 3;

Regulate the total dispersion amount DL of chirped fiber Bragg gratings 9, meet ps/nm, wherein c is the propagation velocity of light in vacuum, f _rF=10GHz is the output sinusoidal signal of sinusoidal wave local oscillator 4;

The bias voltage source offset Δ V of two parallel MZ Mach-Zehnder 3 _bias=0.5%;

The present embodiment ε _rvalue is 25dB, Δ V _biasvalue is 0.5%, f _rF=10GHz, V _π=2V, after above-mentioned adjustment, fiber grating 9 exports as triangle light pulse, and repetition rate is f=4f _rF=40GHz, shown in corresponding time-domain curve Fig. 4.

Embodiment three

A kind of triangle optical pulse generator based on four times of rf modulations, as shown in Figure 1, it is characterized in that: this triangle generator comprises, continuous-wave laser 1, Polarization Controller 2, two parallel MZ Mach-Zehnder 3, sinusoidal wave local oscillator 4,90 ° of electric bridges 5, bias voltage source 6, erbium-doped fiber amplifier 7, band pass filter 8, circulator 9, chirped fiber Bragg gratings 10; Concrete connected mode is:

The input of the light output termination Polarization Controller 2 of continuous-wave laser 1, the light input end of the two parallel MZ Mach-Zehnder 3 of output termination of Polarization Controller 2, the electricity of sinusoidal wave local oscillator 4 exports the electrical input of termination 90 degree of electric bridges 5, 90 degree of electric output ports 51 and 0 degree of electric output port 52 of 90 degree of electric bridges 5 connect the first electric drive port 31 and the second electric drive port 32 of two parallel Mach zehnder modulators 3 respectively, the electricity of bias voltage source 6 exports the voltage bias port 33 of the two parallel Mach zehnder modulators 3 of termination, the light input end of the light output termination erbium-doped fiber amplifier 7 of two parallel Mach zehnder modulators 3, the input of the light output end tape splicing bandpass filter 8 of erbium-doped fiber amplifier 7, the output of band pass filter 8 connects the input 91 of circulator 9, first output 92 of circulator 9 connects the input of chirped fiber Bragg gratings 10, second output 93 of circulator exports triangle light pulse.

Regulate the output voltage V of bias voltage source 6 _bias, make V _bias=V _π=2V, wherein V _πfor the half-wave changing voltage of two parallel Mach zehnder modulators 3.Two sub-MZ and female MZ of two parallel Mach zehnder modulators 3 are offset to maximum transmitted point, maximum transmitted point, minimum transfer point respectively;

The setting index of modulation=π V _rF/ 2V _π=4.438, regulate the sinusoidal signal amplitude V that sinusoidal wave local oscillator 4 exports _rF=2.825V _π=5.65V, wherein V _π=2V is the half-wave changing voltage of two parallel Mach zehnder modulators 3;

Regulate the total dispersion amount DL of chirped fiber Bragg gratings 9, meet wherein c is the propagation velocity of light in vacuum, f _rF=20GHz is the output sinusoidal signal of sinusoidal wave local oscillator 4;

The bias voltage source offset Δ V of two parallel MZ Mach-Zehnder 3 _bias=0.5%;

The present embodiment ε _rvalue is 25dB, Δ V _biasvalue is 0.5%, f _rF=20GHz, V _π=2V, after above-mentioned adjustment, fiber grating 9 exports as triangle light pulse, and repetition rate is f=4f _rF=80GHz, shown in corresponding time-domain curve Fig. 5.

Embodiment four

A kind of triangle optical pulse generator based on four times of rf modulations, as shown in Figure 1, it is characterized in that: this triangle generator comprises, continuous-wave laser 1, Polarization Controller 2, two parallel MZ Mach-Zehnder 3, sinusoidal wave local oscillator 4,90 ° of electric bridges 5, bias voltage source 6, erbium-doped fiber amplifier 7, band pass filter 8, circulator 9, chirped fiber Bragg gratings 10; Concrete connected mode is:

The input of the light output termination Polarization Controller 2 of continuous-wave laser 1, the light input end of the two parallel MZ Mach-Zehnder 3 of output termination of Polarization Controller 2, the electricity of sinusoidal wave local oscillator 4 exports the electrical input of termination 90 degree of electric bridges 5, 90 degree of electric output ports 51 and 0 degree of electric output port 52 of 90 degree of electric bridges 5 connect the first electric drive port 31 and the second electric drive port 32 of two parallel Mach zehnder modulators 3 respectively, the electricity of bias voltage source 6 exports the voltage bias port 33 of the two parallel Mach zehnder modulators 3 of termination, the light input end of the light output termination erbium-doped fiber amplifier 7 of two parallel Mach zehnder modulators 3, the input of the light output end tape splicing bandpass filter 8 of erbium-doped fiber amplifier 7, the output of band pass filter 8 connects the input 91 of circulator 9, first output 92 of circulator 9 connects the input of chirped fiber Bragg gratings 10, second output 93 of circulator exports triangle light pulse.

Regulate the output voltage V of bias voltage source 6 _bias, make V _bias=V _π=2V, wherein V _πfor the half-wave changing voltage of two parallel Mach zehnder modulators 3.Two sub-MZ and female MZ of two parallel Mach zehnder modulators 3 are offset to maximum transmitted point, maximum transmitted point, minimum transfer point respectively;

The setting index of modulation=π V _rF/ 2V _π=4.438, regulate the sinusoidal signal amplitude V that sinusoidal wave local oscillator 4 exports _rF=2.825V _π=5.65V, wherein V _π=2V is the half-wave changing voltage of two parallel Mach zehnder modulators 3;

Regulate the total dispersion amount DL of chirped fiber Bragg gratings 9, meet wherein c is the propagation velocity of light in vacuum, f _rF=30GHz is the output sinusoidal signal of sinusoidal wave local oscillator 4;

The bias voltage source offset Δ V of two parallel MZ Mach-Zehnder 3 _bias=0.5%;

The present embodiment ε _rvalue is 25dB, Δ V _biasvalue is 0.5%, f _rF=30GHz, V _π=2V, after above-mentioned adjustment, fiber grating 9 exports as triangle light pulse, and repetition rate is f=4f _rF=120GHz, shown in corresponding time-domain curve Fig. 6.

Embodiment five

A kind of triangle optical pulse generator based on four times of rf modulations, as shown in Figure 1, it is characterized in that: this triangle generator comprises, continuous-wave laser 1, Polarization Controller 2, two parallel MZ Mach-Zehnder 3, sinusoidal wave local oscillator 4,90 ° of electric bridges 5, bias voltage source 6, erbium-doped fiber amplifier 7, band pass filter 8, circulator 9, chirped fiber Bragg gratings 10; Concrete connected mode is:

The input of the light output termination Polarization Controller 2 of continuous-wave laser 1, the light input end of the two parallel MZ Mach-Zehnder 3 of output termination of Polarization Controller 2, the electricity of sinusoidal wave local oscillator 4 exports the electrical input of termination 90 degree of electric bridges 5, 90 degree of electric output ports 51 and 0 degree of electric output port 52 of 90 degree of electric bridges 5 connect the first electric drive port 31 and the second electric drive port 32 of two parallel Mach zehnder modulators 3 respectively, the electricity of bias voltage source 6 exports the voltage bias port 33 of the two parallel Mach zehnder modulators 3 of termination, the light input end of the light output termination erbium-doped fiber amplifier 7 of two parallel Mach zehnder modulators 3, the input of the light output end tape splicing bandpass filter 8 of erbium-doped fiber amplifier 7, the output of band pass filter 8 connects the input 91 of circulator 9, first output 92 of circulator 9 connects the input of chirped fiber Bragg gratings 10, second output 93 of circulator exports triangle light pulse.

Regulate the output voltage V of bias voltage source 6 _bias, make V _bias=V _π=2V, wherein V _πfor the half-wave changing voltage of two parallel Mach zehnder modulators 3.Two sub-MZ and female MZ of two parallel Mach zehnder modulators 3 are offset to maximum transmitted point, maximum transmitted point, minimum transfer point respectively;

The setting index of modulation=π V _rF/ 2V _π=4.438, regulate the sinusoidal signal amplitude V that sinusoidal wave local oscillator 4 exports _rF=2.825V _π=5.65V, wherein V _π=2V is the half-wave changing voltage of two parallel Mach zehnder modulators 3;

Regulate the total dispersion amount DL of chirped fiber Bragg gratings 9, meet wherein c is the propagation velocity of light in vacuum, f _rF=40GHz is the output sinusoidal signal of sinusoidal wave local oscillator 4;

The bias voltage source offset Δ V of two parallel MZ Mach-Zehnder 3 _bias=0.5%;

The present embodiment ε _rvalue is 25dB, Δ V _biasvalue is 0.5%, f _rF=40GHz, V _π=2V, after above-mentioned adjustment, fiber grating 9 exports as triangle light pulse, and repetition rate is f=4f _rF=160GHz, shown in corresponding time-domain curve Fig. 7.

Claims (2)

1. the optical triangulation shape pulse generator based on four times of rf modulations, it is characterized in that: this triangle generator comprises, continuous-wave laser (1), Polarization Controller (2), two parallel MZ Mach-Zehnder (3), sinusoidal wave local oscillator (4), 90 ° of electric bridges (5), bias voltage source (6), erbium-doped fiber amplifier (7), band pass filter (8), circulator (9), chirped fiber Bragg gratings (10); Concrete connected mode is:

The input of the light output termination Polarization Controller (2) of continuous-wave laser (1), the light input end of the two parallel MZ Mach-Zehnder (3) of output termination of Polarization Controller (2), the electricity of sinusoidal wave local oscillator (4) exports the electrical input of termination 90 degree of electric bridges (5), 90 degree of electric output ports (51) and 0 degree of electric output port (52) of 90 degree of electric bridges (5) connect the first electric drive port (31) and the second electric drive port (32) of two parallel Mach zehnder modulators (3) respectively, the voltage bias port (33) of the two parallel Mach zehnder modulators (3) of output termination of bias voltage source (6), the light input end of the light output termination erbium-doped fiber amplifier (7) of two parallel Mach zehnder modulators (3), the input of the light output end tape splicing bandpass filter (8) of erbium-doped fiber amplifier (7), the output of band pass filter (8) connects the input (91) of circulator (9), first output (92) of circulator (9) connects the input of chirped fiber Bragg gratings (10), second output (93) of circulator exports triangle light pulse.

2. a kind of optical triangulation shape pulse generator based on four times of rf modulations according to claim 1, is characterized in that:

Regulate the output voltage V of bias voltage source (6) _bias, make V _bias=V _π, wherein V _πfor the half-wave changing voltage of two parallel Mach zehnder modulators (3), and 2V≤V _π≤ 4V; Two sub-MZ and female MZ of two parallel Mach zehnder modulators (3) are offset to maximum transmitted point, maximum transmitted point, minimum transfer point respectively;

Setting index of modulation m=π V _rF/ 2V _π=4.438, regulate the sinusoidal signal amplitude V that sinusoidal wave local oscillator (4) exports _rF=2.825V _π;

Regulate the total dispersion amount DL of chirped fiber Bragg gratings (9), meet wherein c is the propagation velocity of light in vacuum, f _rFfor the output sinusoidal signal of sinusoidal wave local oscillator (4), its frequency is 1GHz≤f _rF≤ 40GHz;

The bias voltage source offset Δ V of two parallel MZ Mach-Zehnder (3) _bias, its scope is-0.5%≤Δ V _bias≤ 1%;

Through above-mentioned setting, circulator (9) exports as triangle light pulse, and repetition rate is f=4f _rF.