CN201038593Y - A Wavelength Tunable External Injection Gain Switched Laser - Google Patents

Abstract

The utility model relates to a gain switch laser, in particular to an external injection gain switch laser with tunable wavelength. The utility model comprises a gain switch laser body, an optical fiber amplifier, a narrow-band adjustable filter, a first coupler and a second coupler; the first coupler, the optical fiber amplifier, the narrow-band adjustable filter and the second coupler pass through the optical fiber string Connected to the signal output end of the gain switch laser body, the second coupler is connected to the first coupler through the output fiber. In order to solve the technical problems of the gain switch laser in the background technology, the utility model provides an external injection gain switch laser with tunable wavelength, wide application range, simple structure, small volume, low cost and pure spectrum.

Description

A kind of Wavelength-tunable exterior injection type gain switch laser

Technical field

The utility model relates to a kind of gain switch laser, especially a kind of exterior injection type gain switch laser of tunable wave length.

Background technology

The ultrashort light pulse source is to realize one of ultrahigh speed, big capacity System of all Optical Communication and server parts, and it also has important use to be worth at aspects such as ultra-wideband-light signal sampling, optical storage, ultra high-speed optical submodule-number conversions.In actual applications, require the ultrashort light pulse source to have that volume is little, simple in structure, repetition rate is high, shake is low, versatility is good, cost is low and characteristics such as reliability height.During telecommunication is used, be implementation structure compactness, ultra high-speed optical transmitter and the array thereof that can produce in batches, also require the ultrashort light pulse source to have the advantages that to integrate with other optics.

The gain switch of semiconductor laser is a kind of simple, reliable ultrashort light pulse technology, can be conveniently used in the existing commercialization semiconductor laser, can export the picosecond light pulse signal of variable repetition frequency neatly, adapt to different communication interface rate or network upgrade and regenerate, the different data rate signal is carried out ultrafast sampling and waveform monitoring etc.Though gain switch laser exists timing jitter and the big problem of frequency chirp, can adopt modes such as optical injection-locked and light filtering to solve.

The optical injection-locked mode of gain switch laser can be divided into the outer two kinds of methods of injecting and inject certainly.Though adopt the outer problem of the harmonious inhibition shake of wavelength-tunable of injecting and can solving the light pulse signal of gain switch from method for implanting, require the exocoel loop-length L of gain switch laser and the repetition rate f of the ultrashort light pulse periodic sequence that produced from method for implanting _rFormula relation is 1. satisfied in strictness:

$f_r=\frac{m}{\mathrm{\τ}}$ ①

Wherein m is a positive integer, and τ is that a ultrashort optical pulse signal is by this needed transmission time of exocoel loop.If the transmission rate of light pulse signal in the exocoel loop is v, then $\mathrm{\τ}=\frac{L}{v}$ 。The exocoel loop design is finished, and exocoel loop-length L value is promptly fixing, from the repetition rate f of the ultrashort light pulse periodic sequence that pouring-in gain switch laser produced _rJust can 1. determine, and gain switch has just lost flexibly changing light pulse signal repetition rate f by formula _rCharacteristic.In the practical application, influenced by ambient temperature conversion etc., be difficult on the engineering guarantee that the interface data speed of communication system and network is the 1. determined repetition rate f of formula all the time _r, this is very limited with regard to feasible range of application from pouring-in gain switch laser.Though outer method for implanting can address this problem, but exterior injection type gain switch laser needs additionally to use narrow breadth of spectrum line continuous wave (CW) light source of a tunable wave length to make the outside seed light source that injects usually again, and the result will cause the increase of gain switch laser cost, complex structure and volume to increase.

The utility model content

The utility model is for solving the technical problem that gain switch laser exists in the background technology, and a kind of tunable, applied range is provided, and is simple in structure, volume is little, cost is low, the exterior injection type gain switch laser of specpure tunable wave length.

Technical solution of the present utility model is: the utility model is a kind of Wavelength-tunable exterior injection type gain switch laser, comprise the gain switch laser body, its special character is: described laser also comprises fiber amplifier, the arrowband tunable filter, first coupler, second coupler; First coupler, fiber amplifier, arrowband tunable filter and second coupler are connected in the signal output part of gain switch laser body successively by optical fiber, second coupler inserts first coupler by output optical fibre.

Above-mentioned gain switch laser body is the gain switch laser that is made of F-P semiconductor laser, radio-frequency signal generator, radio frequency signal amplifiers and direct current biasing power supply.

Above-mentioned fiber amplifier is Erbium-Doped Fiber Amplifier or optical semiconductor fiber amplifier, and other can cover required wave band solid image intensifer.

The also available adjustable optic fibre grating of above-mentioned arrowband tunable filter and other adjustable narrow-band spectrum component selectors.

Above-mentioned first coupler and second coupler are fiber coupler or spectroscope and some other beam separation device.

The utility model is on the basis of existing gain switch laser, increased fiber amplifier, the arrowband tunable filter, first coupler, second coupler, carry out light signal by fiber amplifier and amplify, by being arranged at the arrowband tunable filter of fiber amplifier output, can screening the narrow spectral line light component that is positioned at spontaneous radiation ASE noise frequency range.Constitute the light signal feedback loop by first coupler and second coupler, make the spectral components signal of arrowband tunable filter output corresponding to certain longitudinal mode of gain switch laser body, and when this signal of small part being injected into the gain switch laser body by second coupler, longitudinal mode concussion corresponding with injecting wavelength of optical signal in the gain switch laser body cavity strengthens, change the output wave long value of arrowband tunable filter, and it is each all corresponding to each different longitudinal modes of gain switch laser body, then the centre wavelength of the operation of the single longitudinal mode in the gain switch laser body cavity changes thereupon, thereby realize the tunable of gain switch laser wavelength, the utility model is gone into the sharp device body of gain switch by this signal re-injection of sub-fraction simultaneously, most of output, elimination other longitudinal modes that do not suppress fully, the spectrum of output is very pure, therefore the utlity model has following advantage:

1, simple in structure, be easy to make, but optics is integrated.

2, the utility model has not only kept the characteristic of gain switch flexibly changing light pulse repetition rate, and do not need the narrow spectral line continuous wave laser of tunable wave length to inject the function that seed light source just can be realized tunable wave length as special outside, not only simplify system configuration, and reduced system cost and volume.

3, pure and little, the good stability of single longitudinal mode, timing jitter and frequency chirp of output spectrum.

Description of drawings

Fig. 1 is a structured flowchart of the present utility model;

Fig. 2 is that the utility model is the spectrogram of exporting under the optical injection-locked of 1541nm at wavelength;

Fig. 3 is the constitutional diagram of the spectrogram exported under different optical injection-lockeds of the utility model;

Fig. 4 is the ultrashort light pulse sequence of the utility model repetition rate when being 1GHz;

Fig. 5 is the ultrashort light pulse sequence of the utility model repetition rate when being 2.5GHz.

Embodiment

Referring to Fig. 1, the utility model comprises gain switch laser body 1, fiber amplifier 7, arrowband tunable filter 8, the first couplers 6 and second coupler 9; First coupler 6, fiber amplifier 7, arrowband tunable filter 8 and second coupler 9 are connected in the signal output part of gain switch laser body 1 successively by optical fiber, second coupler 9 inserts first coupler 6 by output optical fibre.

Gain switch laser body 1 can adopt existing gain switch laser, as adopts the existing gain switch laser that is made of F-P semiconductor laser (Fabry one glass sieve semiconductor laser) 4, radio-frequency signal generator 2, radio frequency signal amplifiers 3 and direct current biasing power supply 5.Because the light pulse signal power of gain switch laser output is general lower, in the practical application, will adopt optical amplifier to strengthen its power usually.

Fiber amplifier 7 can adopt Erbium-Doped Fiber Amplifier or optical semiconductor fiber amplifier, and other can cover required wave band solid image intensifer.To adopt Erbium-Doped Fiber Amplifier is good.By the ultrashort light pulse sequence signal that the output of gain switch laser body has many longitudinal modes spectral characteristic, input optical fibre amplifier 7 can carry out light signal and amplify.

The also available adjustable optic fibre grating of arrowband tunable filter 8 and other adjustable narrow-band spectrum component selectors.Because fiber amplifier 7 can produce amplified spontaneous emission ASE (amplifiedspontaneous emission) noise of wide spectrum, by being arranged at the arrowband tunable filter 8 of fiber amplifier 7 outputs, can screening the narrow spectral line light component that is positioned at spontaneous radiation ASE noise frequency range.For locking the outside light signal that injects, regulate arrowband tunable filter 8, the centre wavelength of selected narrow spectral components signal is identical with one of them longitudinal mode of gain switch laser body 1, then the light signal of arrowband tunable filter 8 outputs promptly can be used as external seed light re-injection to gain switch laser body 1, longitudinal mode concussion selected in gain switch laser body 1 chamber is obviously strengthened, suppressed other longitudinal mode in gain switch laser body 1 chamber simultaneously.Thereby guarantee the single longitudinal mode running of gain switch laser body 1, and effectively suppress timing jitter.

First coupler 6 and second coupler 9 are fiber coupler or spectroscope and some other beam separation device.First coupler 6 and second coupler 9 constitute the light signal feedback loop, because the gain spectrum of fiber amplifier 7 spontaneous radiations is very wide, when the spectral components signal of tunable filter 8 outputs in arrowband corresponding to certain longitudinal mode of gain switch laser body 1, and when by the light signal feedback loop this signal being injected into gain switch laser body 1 by second coupler 9 with this signal of small part, longitudinal mode concussion corresponding with injecting wavelength of optical signal in gain switch laser body 1 chamber strengthens.Change the output wave long value of arrowband tunable filter 8, and it is each all corresponding to each different longitudinal modes of gain switch laser body 1, then the centre wavelength of the operation of the single longitudinal mode in gain switch laser body 1 chamber changes thereupon, thereby realizes the tunable of gain switch laser body 1 wavelength.Simultaneously at gain switch laser body 1 during from 8 outputs of arrowband tunable filter, allow this signal re-injection of sub-fraction go into gain switch and swash device body 1, most of output, elimination other longitudinal modes that do not suppress fully, the spectrum of output is very pure, solved the general outer back spectrum impure phenomenon of injecting, to the transmission of signal with amplify very big benefit is all arranged.

Referring to Fig. 2,3, after adopting novel outside injection mode of the present utility model, arrowband tunable filter 8 filters out the spectral components signal corresponding to certain longitudinal mode of gain switch laser body 1, and it is injected into F-P semiconductor laser 4 in the gain switch laser body 1 by the light signal feedback loop, realize the single longitudinal mode running status of gain switch laser body 1, change the output wave long value of spectral components signal selector, and make it each all corresponding to each different longitudinal modes of gain switch laser body 1, can realize tunable wave length, simultaneously, also reduced the frequency chirp of gain switch light pulse signal.

Change situation about changing referring to Fig. 4, the 5 output optical pulse signal repetition rates that record for experiment with input radio frequency sinusoidal signal or cosine signal repetition rate.Gain switch laser of the present utility model can realize repetition rate variable, low jitter, single longitudinal mode operation.

Claims (5)

1. A wavelength tunable external injection gain switch laser, comprising a gain switch laser body, characterized in that: the laser also includes a fiber amplifier, a narrowband tunable filter, a first coupler, and a second coupler; The first coupler, the fiber amplifier, the narrow-band tunable filter and the second coupler are sequentially connected in series to the signal output end of the gain switch laser body through an optical fiber, and the second coupler is connected to the first coupler through an output optical fiber. 2. The wavelength tunable external injection gain switch laser according to claim 1, characterized in that: the gain switch laser body is composed of an F-P semiconductor laser, a radio frequency signal generator, a radio frequency signal amplifier and a DC bias power supply Gain-switched lasers. 3. The wavelength tunable external injection gain switch laser according to claim 1 or 2, characterized in that: the optical fiber amplifier is an erbium-doped optical fiber amplifier or a semiconductor optical fiber amplifier. 4. The wavelength tunable external injection gain switch laser according to claim 3, characterized in that: the narrowband tunable filter adopts a tunable fiber grating or a tunable narrowband spectral component selector. 5. The wavelength tunable external injection gain switch laser according to claim 4, characterized in that: both the first coupler and the second coupler are fiber couplers or beam splitters.

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