CN102916340B - Phase-shift electric-control sampling grating semiconductor laser and setting method therefor - Google Patents

Abstract

The invention proposes a phase-shift electric-control sampling grating semiconductor laser. A DFB (distributed feed back) semiconductor laser consists of a first sampling grating area, a second sampling grating area and a phase-shift area, wherein gratings in the two sampling grating areas are sampling bragg gratings (SBG), the phase-shift area is positioned in the middle, and the sampling period is 1-10 micrometers; electrodes of the two sampling grating areas are connected together and are isolated from an electrode of the phase-shift area; the effective refractive index and the length of the sampling grating areas are expressed by nSBG and nP, and the effective refractive index and the length of the phase-shift area are expressed by LSBG and LP; and the primary control on the hot-shot wavelength of the laser can be realized only by changing the sampling period P, so as to form the phase-shift electric-control SBG DFB semiconductor laser.

Description

Phase shift electrically controlled sampling grating semiconductor laser and its setting method

technical field

The invention belongs to the technical field of optoelectronics, and relates to optical fiber communication, photon integration, photoelectric sensing and other photoelectric information processing; it is a sampling grating semiconductor laser with continuously adjustable wavelength within a certain range and a setting method.

Background technique

Due to the rapid increase in the demand for the transmission capacity of optical communication networks, the number of multiplexed channels in Dense wavelength division multiplexing (WDM) systems is increasing. This communication system needs to use lasers with different lasing wavelengths as lasers. light source. In order to reduce the resulting sharp rise in energy consumption and maintenance costs, photonic integration circuit (PIC) is an inevitable choice. However, the high-performance light source used in this large-scale integrated PIC chip, the laser array, can only be manufactured by high-precision electron beam writing technology. For real phase-shift gratings that meet the ITU-T standard wavelength, this electron beam writing technology requires a processing accuracy of at least 0.1 nanometers, and can only be processed by specially modified electron beam exposure equipment, and its processing technology is slow. Time-consuming, processing costs are very high, and cannot be used for large-scale commercial production of lasers.

In addition, the ITU-T standard puts forward strict requirements on the lasing wavelength of the laser, but in the actual semiconductor laser manufacturing process, there are various accidental factors that make the lasing wavelength of the laser deviate from this requirement. Therefore, when making a multi-wavelength laser array, wavelength tuning devices such as thermal tuning or changing the injection current, and multi-electrode injection are often used to control the lasing wavelength of the laser to strictly align with the ITU-T standard. These wavelength tuning devices complicate the structure of the laser and increase the difficulty of processing, and they also cause the problem of unbalanced output laser power of each laser in the multi-wavelength laser array.

For the preliminary control of the lasing wavelength of the laser, the reconstruction-equivalent chirp (REC) technology invented by Professor Chen Xiangfei of Nanjing University has great advantages. Using this sampling grating technology, micron-level processing technology can be used to replace the wavelength control that originally required nano-level technology, and the production cost is greatly reduced. It is especially suitable for the production of multi-wavelength semiconductor laser arrays in PIC equipment. For the fine adjustment of the lasing wavelength of the laser, the method of introducing a phase shift region in the middle of the DFB laser proposed by T. Numai et al. has great advantages. Experimental reports show that the laser can be continuously adjusted by changing the current injected into the phase shift region. The lasing wavelength reaches 2.1nm. Our theoretical research shows that under the existing technological conditions, the continuously adjustable range of the lasing wavelength of this laser can be as high as 5-6nm. The advantage of this kind of laser is that in the process of continuous adjustment of the lasing wavelength, the output laser power of the laser threshold current and normal operating current (two to three times the threshold current) does not change much. This method makes multi-wavelength laser arrays.

main reference

[1] Tingye, L., Advances in optical fiber communications: an historical perspective. IEEE Journal on Selected Areas in Communications, 1983. 1(3): 356-371.

[2] Ishio, H., J. Minowa, and K. Nosu, Review and status of wavelength-division-multiplexing technology and its application. Journal of Lightwave Technology, 1984. 2(4): 448-463.

[3] Keizer, G.E., A Review of WDM Technology and Applications. Optical Fiber Technology, 1999. 5: p. 37.

[4] Chen, X.F., et al., Photonic integrated technology for multi-wavelength laser emission. Chinese Science Bulletin, 2011. 56(28-29): 3064-3071.

[5] Tennant, D. and T. Koch, Fabrication and uniformity issues in λ/4 shifted DFB laser arrays using e-beam generated contact grating masks. Microelectronic Engineering, 1996. 32(1-43):41331

[6] Steingr¨ber, R., et al., Continuously chirped gratings for DFB-lasers fabricated by direct write electron-beam lithography. Microelectronic Engineering, 2002. 61-62: 331-335.

[7] Sakano, S., et al., Tunable DFB laser with a striped thin-film heater. IEEE Photonics Technology Letters, 1992. 4(4): 321-323.

[8] Hansmann, S., et al., Static and Dynamic Properties of InGaAsP-InP Distributed-Feedback Lasers—a Detailed Comparison between Experiment and Theory. IEEE Journal of Quantum Electronics, 2(417. 2: 417. 3)

[9] Dutta, N., et al., Electronically tunable distributed feedback lasers. Applied Physics Letters, 1986. 48(22): 1501-1503.

[10] Dai, Y., et al., Sampled Bragg grating with desired response in one channel by use of a reconstruction algorithm and equivalent chirp. Optics Letters, 2004. 29(12): 13533－13

[11] Chen, X., et al., Analytical expression of sampled Bragg gratings with chirp in the sampling period and its application in dispersion management design in a WDM system. IEEE Photonics Technology 30 Letters, 2(1 80 Letters): 2 1015.

[12] Feng, J., et al., A novel method to achieve various equivalent chirp profiles in sampled Bragg gratings using uniform-period phase masks. Optics Communications, 2002. 205: 71-75.

[13] Dai, Y., et al., Equivalent phase shift in a fiber Bragg grating achieved by changing the sampling period. IEEE Photonics Technology Letters, 2004. 16(10): 2284-2296.

[14] Numai, T., 1.5 μm phase-controlled distributed feedback wavelength tunable optical filter. IEEE Journal of Quantum Electronics, 1992. 28(6): 1513-1519.

[15] H. Ghafouri-Shiraz, et al., Analysis of a λ/4-Phase-Shifted Double Phase-Shift-Controlled Distributed Feedback Wavelength Tunable Optical Filter. IEEE Journal of Quantum 5 Electronics, 1997: 35(3647). -561.

[16] Y. KOTAKI, et al., Tunable, narrow-linewidth and high-power lambda 4-shifted DFB laser. Electronics Letters, 1989. 25(15): 990-992.

[17] Nobuhiro Nunoya, et al. Novel tunable DFB laser with separated high coupling coefficient gratings. in 2006 International Conference on Indium Phosphide and Related Materials Conference. 2006: 68-71.

Contents of the invention

The purpose of the present invention is to, in order to make the lasing wavelength of the semiconductor laser satisfy the ITU-T standard, propose a kind of utilization sampling grating technology to carry out preliminary control to the lasing wavelength of the semiconductor laser, then by changing two sampling grating areas and The method of injecting current in the intermediate phase shift region to obtain different phase shift values, and then the method and device for finely adjusting the lasing wavelength of the laser, proposes a new structure and process for the design and manufacture of DFB semiconductor lasers.

The object of the present invention is to propose a sampling grating semiconductor laser with adjustable lasing wavelength and its manufacturing method. The sampling grating technology is used to set two sampling grating areas, and a phase shift area is arranged in the middle of the two sampling grating areas to form a sampling Grating laser, based on sampling grating technology and phase-shift current injection control technology to obtain adjustable wavelength distribution feedback (DFB) semiconductor laser and its manufacturing method.

The technical solution of the present invention is: a sampling grating semiconductor laser based on phase shift electrical control, and the DFB semiconductor laser structure is composed of two sampling grating regions and a phase shift region. The gratings in the sampling grating areas on both sides are sampled Bragg gratings (Sampled Bragg grating, SBG), and the phase shift area in the middle can have no grating, or can have the same SBG as the sampling grating area, and the sampling period is from 1 micron to tens of microns , the electrodes of the two sampling grating regions are connected together, but separated from the electrodes of the phase shift region.

Usually, one of the sub-gratings of the ±1st level of the sampling grating is selected as the lasing channel; in addition, in order to ensure that only the selected lasing channel is lasing and the zero-order channel is not lasing, when selecting the semiconductor material for making the laser, the semiconductor The gain region of the material is centered at the selected lasing channel Bragg wavelength and away from the zero-order channel Bragg wavelength.

1. Ordinary uniform sampling grating

FIG. 1 is a schematic diagram of a common uniform sampling template, where a is the length of a grating portion in a sampling period, and P is the sampling period. Mathematically, the refractive index modulation of a sampled Bragg grating It can be expressed as

(1)

it's here, and are the refractive index modulation depth and grating period of the seed grating, respectively, represents the complex conjugate. Sampling function in Figure 1 , according to Fourier analysis, it can be expressed as

(2)

The m-th order Fourier coefficient of the sampled grating can be expressed as

(3)

Substituting equations (2) and (3) into equation (1), we can get

(4)

It can be seen from formula (4) that a sampling grating can be regarded as a superposition of many shadow gratings (one shadow grating corresponds to one channel). The period of the mth shadow grating It can be expressed as

(5)

Therefore, in the m-th order shadow grating, the Bragg wavelength can be expressed as

(6)

is the effective refractive index. Sampling Duty Cycle is defined as the ratio of the length of the uniform grating to the sampling period, that is,

(7)

If the form of sampling is a periodic square wave, according to the above theoretical calculation results, that is, the formulas (1) to (4), it can be known that in any sub-grating of a sampling grating except the 0th level, the ±1th The refractive index modulation intensity in the first-level sub-grating is the largest, so when the sampling grating structure is used to make a DFB laser, one of the ±1st-level sub-gratings is usually selected as the lasing channel. In the ±1st sub-grating of the sampled grating, the refractive index modulates the intensity The relationship with the sampling duty cycle is

(8)

The relationship between the refractive index modulation intensity and the sampling duty cycle in the ±1st-level sub-gratings is shown in Fig. 2 . From Equation (8) and Figure 2, it can be seen that the duty cycle =0.5, the refractive index modulation intensity in the ±1st-level sub-gratings is the largest, and the feedback effect on the Bragg wavelength of the ±1st-level sub-gratings is the strongest. duty cycle The more the deviation is from 0.5, the smaller the refractive index modulation intensity in the ±1st-level sub-gratings is, and the weaker the feedback effect on the Bragg wavelength of the ±1st-level sub-gratings is.

Taking the -1st level sub-grating as an example, formulas (5) and (6) change to

(9)

(10)

For an ordinary uniform grating, the Bragg wavelength It can be expressed as

(11)

From equations (9) to (11), it can be seen that to control the size of the Bragg wavelength in the same way, it is necessary to change the grating period in the ordinary uniform grating The size of the sampling grating only needs to change the size of the sampling period P. In semiconductor lasers, the former is about two hundred nanometers, the latter is several microns to tens of microns, and the latter is one to two orders of magnitude larger than the former. Therefore, to control the size of the Bragg wavelength, it is much easier to use a sampling grating (using its ±1-level sub-grating) than a uniform grating.

2. Phase-shift electrical control method

The structure of the phase-shift electrically controlled sampling grating laser device can be schematically represented by FIG. 3 . Its structural characteristics are described as follows: the gratings in the sampled grating areas on both sides are sampled Bragg gratings (Sampled Bragg grating, SBG), and the phase shift area in the middle has no grating, and can also have the same SBG as the sampled grating area. The electrodes in the sampling grating section are connected together but isolated from the electrodes in the phase shifting section. The effective refractive index and length of the sampling grating area and the phase shift area are respectively used and , and To represent.

The gain center of the active layer is set at the Bragg wavelength of one of the ±1st order sub-gratings of the sampled grating (usually at the Bragg wavelength of the -1 level sub-grating, so here we take the -1 level sub-grating as an example to illustrate), there is

(12)

When different current densities are injected into the sampling grating area and the phase shift area, due to the plasma effect of free carriers, and will be different, and thus will produce a phase shift in the phase shift region , with a size of

(13)

It can be seen from formula (10) that if the period of the seed grating remains unchanged, the initial control of the lasing wavelength of the laser can be achieved only by changing the size of the sampling period P.

When the sampling period P is determined, the current is injected into the sampling grating area and the phase shift area , The sum of the laser operating current ( + ) remains unchanged, from formula (13) it can be seen that the change and The ratio of the ratio can change the size of the introduced phase shift, and the value of the lasing wavelength can be adjusted arbitrarily within the range of the forbidden band width (usually 2-5nm) of the sampling grating ± 1-level sub-grating. In order to reduce the crosstalk between the injection current in the sampling grating area and the phase shift area, and improve the effect of changing the phase shift and finely adjusting the lasing wavelength of the laser, helium ion implantation can also be used for electrical isolation between the sampling grating area and the phase shift area. When the introduced phase shift is in the range of 0.25π-1.75π, the threshold current of the laser and the output laser power of the laser during normal operation (the operating current is 2 to 3 times the threshold current) change very little.

Since the phase shift in the present invention is distributed over the entire phase shift region, it is a gradually cumulative phase shift, which can better suppress the common hole-burning effect in phase-shift lasers compared with abrupt phase shifts.

The second type of sampling grating semiconductor laser based on phase shift electrical control has the same basic structure and characteristics as the above-mentioned DFB semiconductor laser. The difference is that the sampling duty cycle of the two sampling grating areas with the same length is different, and the sampling duty cycle of the former part is 0.5, the sampling duty cycle of the latter part It is an optimal value between 0.2 and 0.5.

From Equation (8) and Figure 2, it can be seen that the duty cycle =0.5, the refractive index modulation intensity in the ±1st-level sub-gratings is the largest, and the feedback effect on the Bragg wavelength of the ±1st-level sub-gratings is the strongest. duty cycle The more the deviation is from 0.5, the smaller the refractive index modulation intensity in the ±1st-level sub-gratings is, and the weaker the feedback effect on the Bragg wavelength of the ±1st-level sub-gratings is.

Therefore, in the case of a certain laser power, the sampling duty cycle of the latter part The greater the deviation from 0.5, the greater the effective output laser power of the sampled grating area from this side. In the case where end-face coating is not possible, optimize the sampling duty cycle of the latter part , which can increase the effective output laser power of the laser from the end face of one side of the sampling grating area.

The third type of sampling grating semiconductor laser based on phase shift electrical control has the same structure and features as the basic structure of the DFB semiconductor laser. The difference is that the lengths of the same sampling grating areas of the two sampling gratings are different.

When the sampling gratings in the sampling grating area of the laser are the same, the longer the length of the sampling grating area, the stronger the feedback effect on the lasing wavelength. When the length of the sampling grating area on one side of the laser of the present invention remains constant, the smaller the length of the sampling grating area on the other side, the greater the laser power emitted from this side.

Therefore, when the laser power is constant and the end face coating cannot be performed, optimizing the length of the two sampling grating regions of the laser can increase the effective output laser power of the laser from the side of the shorter sampling grating region.

The above three sampling grating semiconductor lasers based on phase shift electrical control are unit lasers, which can form a monolithic integrated phase shift electrical control sampling grating semiconductor laser array.

For a laser array composed of such semiconductor lasers, under the same operating current and operating temperature, the threshold current and output laser power of each laser can be kept approximately equal, which produces laser modulation, coupling and transmission bands for the laser array. It is very convenient.

The above three sampling grating semiconductor laser arrays based on phase-shift electrical control constitute a PIC emission chip module, which consists of a laser monitor array, a phase-shift electrical control sampling grating semiconductor laser array, and a modulator array (note: no modulation is required for direct modulation) Device array), power equalizer array and multiplexer, which are sequentially grown and integrated on the same epitaxial wafer through selective area epitaxial growth or butt growth technology.

The beneficial effects of the invention are: the sampling grating technology is combined with electric injection control to introduce phase shift, the lasing wavelength of the laser can be flexibly controlled, and the laser maintains superior performance. Using the sampling grating technology, the control of the sampling period which is one to two orders of magnitude larger than the period of the seed grating can be used to effectively realize the basic control of the lasing wavelength of the laser. The lasing wavelength deviation caused by uncontrollable factors in the growth process of laser chip materials can be finely adjusted by introducing phase shift through electrical injection control. When the introduced phase shift is appropriate, such as 0.25π~1.75π, it not only ensures the realization of single-mode lasing of the laser, but also makes the sampled grating laser with similar structure (only the sampling period and the introduced phase shift are different). Similar threshold and lasing characteristics. For a laser array composed of such semiconductor lasers, the output laser power of each laser can be kept roughly equal when the phase shift is not in the range of 0.25π-1.75π, the operating current is the same, and the operating temperature is the same, which gives the laser The modulation, coupling and transmission of the laser generated by the array bring great convenience. The semiconductor laser array in the present invention has great advantages in the development of PIC emitting chip modules. In the wavelength continuously adjustable range, the threshold current of each unit laser hardly changes, and the output laser power does not change much under the same operating current, so this multi-wavelength laser array has superior transmission, modulation and coupling. characteristic. In addition, the use of sampling grating technology greatly reduces the requirements for processing accuracy, so the multi-wavelength laser array has a lower manufacturing cost.

Description of drawings

Figure 1. Schematic diagram of a sampling template for a uniformly sampled grating.

Figure 2. Refractive index modulation intensity versus sampling duty cycle in ±1-level sub-gratings.

Fig. 3. Schematic diagram of the structure of a phase-shifted electrically controlled sampling grating laser.

Fig. 4. Schematic diagram of a sampling template of a phase shift electrically controlled sampling grating laser.

Fig. 5. Schematic diagram of sampling grating produced by interference of double ultraviolet light beams passing through the sampling template.

Specific implementation method:

1, the key that obtains phase-shift electrical control sampling grating semiconductor laser among the present invention is the making of sampling grating structure, and concrete method is

First, design and manufacture the required sampling pattern on the grating mask. As shown in Figure 4, the characteristics of the sampling pattern are: the sampling gratings along the entire laser structure are uniform sampling gratings with the same sampling period, but the phase shift area in the middle of the sampling grating area can be the same sampling grating as the sampling grating area , or no grating exists.

Then, two coherent ultraviolet beams are used to pass through the sampling template and perform double-beam interference, and the double-beam interference pattern and the sampling pattern are simultaneously transcribed onto the photoresist, as shown in Figure 5. 1:n-InP substrate 2:n-InP buffer layer 3:Lower confinement layer 4:Multiple quantum well active layer 5:Upper confinement layer 6:U-InP+1.3μm InGaAsP layer (for making SBG grating) 7:Optical Engraving 8: Sampling template.

2. The structure of the phase-shift electrically controlled sampling grating semiconductor laser

Phase-shift electrically controlled sampling grating semiconductor laser devices, from bottom to top are: n-electrode, n-type InP substrate material, epitaxial n-type InP buffer layer, non-doped lattice matching InGaAsP lower confinement layer, strained InGaAsP multi-quantum well active Layer, non-doped lattice matching InGaAsP upper confinement layer, sampling grating layer, p-type InP layer grown by secondary epitaxial growth, p-type InGaAs ohmic contact layer and p-electrode.

3. Fabrication of Phase Shift Electrically Controlled Sampling Grating Semiconductor Laser in the present invention

The specific manufacturing method of the laser described in the present invention and the photon emitting module chip including the laser array will be described below by using the manufacturing process of the phase-shift electrically controlled sampling grating semiconductor laser with an operating wavelength in the range of 1550 nm.

(1) Fabrication of the grating mask: According to the prior design, the sampling pattern mask is made using the common microelectronics process.

(2) Phase-shift electrically controlled sampling grating semiconductor lasers can be fabricated by secondary epitaxial growth through Metal-organic chemical vapor deposition (MOCVD) technology. The details are described as follows: First, an n-type InP buffer layer (thickness 200nm, doping concentration about 1.1′10 ¹⁸ cm ^-2 ) is epitaxially applied on the n-type InP substrate material, and a 100nm-thick non-doped lattice matching InGaAsP lower limit layer, strained InGaAsP multiple quantum wells (photofluorescence wavelength 1.52 microns, 7 quantum wells: well thickness 8nm, 0.5% compressive strain, barrier thickness 10nm, lattice matching material) and 100nm thick p-type lattice matching InGaAsP (doped The concentration is about 1.1′10 ¹⁷ cm ^-3 ) in the upper confinement layer. Next, through the designed sampling photomask, the sampling grating pattern is transferred to the photoresist on the upper confinement layer by means of ordinary exposure combined with double-beam holographic interference exposure, and then material etching is applied to the upper confinement layer. The upper part forms the required asymmetric sampling grating structure. After the grating is fabricated, the p-type InP layer (thickness 1700nm, doping concentration about 1.1′10 ¹⁸ cm ^-2 ) and p-type InGaAs (thickness 100nm, doping concentration greater than 1′10 ¹⁹ cm -2 ) are grown by secondary epitaxy ^{. 2} ) Ohmic contact layer. After the epitaxial growth is completed, the ridge waveguide is fabricated by ordinary photolithography combined with chemical wet etching. The length of the ridge waveguide is generally on the order of hundreds of microns, the width of the ridge is 2 microns, the width of the ridge side groove is 20 microns, and the depth is 1.5 microns. . Then use plasma-enhanced chemical vapor deposition (Plasma-Enhanced Chemical Vapor Deposition, PECVD), deposit a layer of 300nm thick SiO ₂ layer or organic BCB insulating layer around the ridge waveguide. Then use photolithography and chemical wet etching to remove the _SiO2 layer or organic BCB insulating layer above the laser ridge waveguide to expose its InGaAs ohmic contact layer; Plating 100nm-thick Ti and 400nm-thick Au, combined with photolithography and chemical wet etching, formed a Ti-Au metal P electrode on the ohmic contact layer exposing InGaAs above the ridges. In addition, after thinning the entire laser wafer to 150μm, a 500nm-thick Au-Ge-Ni (Au:Ge:Ni composition ratio of 84:14:2) alloy was evaporated under the base material as the n-electrode. There are two cases of whether there is a grating in the phase shift region, but in terms of the performance effect of the laser, the effect without the grating is also good or better.

(3) Fabrication of the photon emission module chip based on the semiconductor laser array of the present invention

The laser monitor array, multi-wavelength laser array, modulator array, power equalizer array and multiplexer based on the semiconductor laser of the present invention are sequentially grown and integrated on the same epitaxial wafer through selective area epitaxial growth or docking growth technology , can be made into an integrated photon emission module chip. By designing, the sampling duty cycle of the sampling grating of the laser on the side of the laser monitor array is 0.5, and the sampling duty cycle of the sampling grating on the side of the modulator array is not equal to an optimal calculated value of 0.5. Or the length of the sampling grating area of the laser on the side of the laser monitor array is greater than the length of the sampling grating area on the side of the modulator array, and the length of the sampling grating area takes the required optimized calculation value. These two methods enable the photon emission module chip to output more lasing power from the direction of the modulator array under the premise that the monitor array obtains a certain lasing power and ensures normal operation.

In order to keep the single-mode characteristic of the laser, in the process of using the present invention, one of the ±1-level channels selected as the lasing channel is designed in the center of the gain region of the semiconductor material, so that the 0-level of the main side mode is far away from the gain region .

Claims (9)

1. A sampling grating semiconductor laser based on phase shift electrical control, characterized in that the DFB semiconductor laser structure adopted is made up of the first and second two sampling grating regions and a phase shift region; the gratings in the sampling grating regions on both sides are Sampling Bragg grating SBG, with a phase shift area in the middle, the sampling period is from 1 micron to tens of microns; the electrodes of the two sampling grating areas are connected together, but separated from the electrodes of the phase shift area; the refraction in the uniform sampling grating Rate modulation intensity, expressed as From formula (4), a sampling grating is equivalent to the superposition of many shadow gratings, and a shadow grating corresponds to a channel; the period of the mth shadow grating is expressed as Therefore, in the m-th order shadow grating, the Bragg wavelength is expressed as n _eff is the effective refractive index, and the sampling duty cycle γ is defined as the ratio of the length of the uniform grating to the sampling period, that is In any level of sub-gratings of a sampling grating except level 0, the refractive index modulation intensity in the ±1st level sub-grating is the largest, so when using the sampling grating structure to make a DFB laser, the ±1st level sub-grating is selected One of them is used as the lasing channel; in the ±1st sub-grating of the sampling grating, the relationship between the refractive index modulation intensity Δn _±1 and the sampling duty cycle is Taking the -1st level sub-grating as an example, formulas (5) and (6) change to The effective refractive index and length of the sampling grating area and the phase shifting area are represented by n _SBG and n _p , L _SBG and L _P respectively; the gain center of the laser active layer is set at one of the ±1-level sub-gratings of the sampling grating The Bragg wavelength λ _B at When different current densities are injected into the sampling grating area and the phase shift area, due to the plasma effect of free carriers, n _SBG and n _p will be different, so a phase shift θ will be generated in the phase shift area, the magnitude of which is It can be seen from formula (10) that if the period of the shadow grating remains unchanged, the initial control of the lasing wavelength of the laser can be achieved only by changing the size of the sampling period P; When the sampling period P is determined, under the condition that the sum of the injection current I _S and I _P in the sampling grating area and the phase shift area, that is, the laser working current (I _S +I _P ), remains constant, it can be known from formula (13) that The ratio of I _S to I _P can change the size of the introduced phase shift, and the value of the lasing wavelength can be adjusted arbitrarily within the forbidden band width of the sampling grating ± 1-level sub-grating, usually within the range of 2 to 5 nm; Among them, Δn _s and Λ ₀ are the refractive index modulation depth and grating period of the seed grating respectively, cc is the complex conjugate, F _m is the mth order Fourier coefficient of the sampling grating, and a is the length of the grating part in a sampling period , P is the sampling period. 2. According to claim 1, based on the sampling grating semiconductor laser controlled by phase shift electricity, it is characterized in that one of the ±1st level sub-gratings of the sampling grating is selected as the lasing channel; the center of the gain region of the semiconductor material is set at the selected lasing channel Bragg wavelength and away from the zero-order channel Bragg wavelength. the 3. according to claim 2 based on the sampling grating semiconductor laser of phase shift electric control, it is characterized in that the sampling duty cycle of two identical sampling grating regions is different, the sampling duty cycle γ _L of the first sampling grating is 0.5, the second The sampling duty cycle γ _R of the two-sampled grating has a value between 0.2 and 0.5. 4. The sampling grating semiconductor laser based on phase-shift electrical control according to any one of claims 1-3, characterized in that the DFB semiconductor laser monolithic integrated array is formed by the phase-shift electrical control sampling grating semiconductor laser. the 5. The sampling grating semiconductor laser based on phase shift electrical control according to claim 4, characterized in that the laser monolithic integrated array constitutes a PIC emitting chip module, composed of a laser monitor array, said sampling based on phase shift electrical control The monolithic integrated array of grating semiconductor lasers, modulator array, power equalizer array and multiplexer are integrated on the same epitaxial wafer through selective area epitaxial growth or butt growth. the 6. The sampling grating semiconductor laser based on phase shift electrical control according to claim 1, characterized in that when the duty cycle is 0.5, the refractive index modulation intensity in the ±1st-level sub-grating is the largest, and for the ±1st-level sub-grating The feedback effect of the Bragg wavelength of the grating is the strongest; the more the duty cycle deviates from 0.5, the smaller the refractive index modulation intensity in the ±1st-level sub-gratings is, and the weaker the feedback effect on the Bragg wavelength of the ±1st-level sub-gratings is. the 7. The sampling grating semiconductor laser based on phase shift electrical control according to claim 3, characterized in that under the certain situation of laser power, the sampling duty ratio γ _L of the former part is 0.5, and the sampling duty ratio of the latter part is 0.5. The more the duty ratio γ _R deviates from 0.5, the greater the effective output laser power from the latter part of the sampling grating area; in the case where the end face coating cannot be performed, optimizing the sampling duty ratio γ _R of the latter part can improve the laser output from the sampling grating area. The effective output laser power of the end face on one side of the zone. 8. The sampling grating semiconductor laser based on phase shift electrical control according to claim 2, characterized in that the longer the sampling grating area, the stronger the feedback effect on the ±1st order sub-grating Bragg wavelength; When the length of the sampling grating area on one side is kept constant, and the laser power is constant, the smaller the length of the sampling grating area on the other side, the greater the laser power emitted from this side; Optimizing the lengths of the two sampling grating regions can increase the effective output laser power of the laser from the end face of the shorter sampling grating region. the 9. The sampling grating semiconductor laser based on phase shift electrical control according to claim 6 is characterized in that for reducing the crosstalk between the sampling grating area and the injection current in the phase shift area, it improves the change and introduces the phase shift fine adjustment laser lasing wavelength Effect, between the sampling grating area and the phase shift area, helium ion implantation is used for electrical isolation; when the introduced phase shift is in the range of 0.25π to 1.75π, the threshold current of the laser is 2 to 3 times that of the normal operation and the working current At the threshold current, the output laser power of the laser changes very little. the