CN114374145A - REC semiconductor laser array wavelength control system - Google Patents
REC semiconductor laser array wavelength control system Download PDFInfo
- Publication number
- CN114374145A CN114374145A CN202210030664.7A CN202210030664A CN114374145A CN 114374145 A CN114374145 A CN 114374145A CN 202210030664 A CN202210030664 A CN 202210030664A CN 114374145 A CN114374145 A CN 114374145A
- Authority
- CN
- China
- Prior art keywords
- tec
- temperature
- laser
- laser array
- independent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000004065 semiconductor Substances 0.000 title claims abstract description 39
- 239000000758 substrate Substances 0.000 claims abstract description 14
- 238000005516 engineering process Methods 0.000 claims description 17
- 238000000034 method Methods 0.000 claims description 14
- 238000007639 printing Methods 0.000 claims description 10
- 238000012545 processing Methods 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 238000001704 evaporation Methods 0.000 claims description 5
- 229910001316 Ag alloy Inorganic materials 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 4
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 4
- 229910052802 copper Inorganic materials 0.000 claims description 4
- 239000010949 copper Substances 0.000 claims description 4
- 229910052709 silver Inorganic materials 0.000 claims description 4
- 239000004332 silver Substances 0.000 claims description 4
- 229910000881 Cu alloy Inorganic materials 0.000 claims description 3
- 238000000151 deposition Methods 0.000 claims description 3
- 230000008020 evaporation Effects 0.000 claims description 3
- 238000004806 packaging method and process Methods 0.000 claims description 2
- 230000033228 biological regulation Effects 0.000 description 5
- 230000001276 controlling effect Effects 0.000 description 4
- 230000017525 heat dissipation Effects 0.000 description 4
- 238000009529 body temperature measurement Methods 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 238000005057 refrigeration Methods 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- SBYXRAKIOMOBFF-UHFFFAOYSA-N copper tungsten Chemical compound [Cu].[W] SBYXRAKIOMOBFF-UHFFFAOYSA-N 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 230000010363 phase shift Effects 0.000 description 1
- 238000001259 photo etching Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
- H01S5/0607—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying physical parameters other than the potential of the electrodes, e.g. by an electric or magnetic field, mechanical deformation, pressure, light, temperature
- H01S5/0612—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying physical parameters other than the potential of the electrodes, e.g. by an electric or magnetic field, mechanical deformation, pressure, light, temperature controlled by temperature
Abstract
The invention discloses a wavelength control system of an REC semiconductor laser array, which comprises an integral TEC, a temperature measuring circuit, a temperature error amplifier, a PID compensating circuit, a TEC driving circuit, an independent TEC, a thermistor and a heat sink, wherein the integral TEC is used for measuring the temperature of the integrated TEC; the independent TEC, the thermistor and the heat sink are arranged inside the laser array chip structure; the TEC driving circuit firstly applies voltage to the integrated TEC arranged on the bottom surface of the substrate, the integrated TEC is adopted to carry out coarse temperature adjustment on the whole laser array chip, then voltage is applied to the independent TEC on the laser unit which does not meet the target temperature electric signal, and the independent TEC is adopted to carry out fine temperature adjustment on the corresponding laser unit. According to the invention, the rough adjustment and the fine adjustment of the temperature are respectively carried out outside and inside the laser array chip, so that each laser channel can output light beams with stable wavelength, and the precise control of the wavelength interval is realized.
Description
Technical Field
The invention relates to the technical field of semiconductor laser array chips, in particular to a REC (Reconfiguration-Equivalent-Chirp) semiconductor laser array wavelength control system.
Background
In a semiconductor laser, a uniform grating waveguide structure cannot meet the current requirements in terms of performance, so that precise structures such as phase shift, chirp and the like are often introduced into a grating. In order to reduce the process requirements, complex gratings such as these can be equivalently implemented using a Reconstruction-Equivalent-Chirp (REC) technique. Compared with the traditional process, the REC technology can improve the precision of the wavelength by about two orders of magnitude, and through estimation, the technology can control the precision of the wavelength to be within +/-0.2 nm. The technology integrates a plurality of laser arrays on one chip, each laser emits light waves with equal wavelength intervals, the size of the whole chip is in the micron order, and the application range of the laser is greatly expanded due to smaller volume and weight.
However, the temperature modulation rate of the semiconductor laser is high, the output wavelength and the output power of the laser array are sensitive to temperature, and the wavelength of the laser can drift due to the change of the temperature in the tube shell, so that crosstalk is generated among different channels, and the preset wavelength cannot be accurately output. When the chip is used in systems such as wavelength division multiplexing, all lasers on the chip are in a working state at the same time, high heat can be accumulated in the lasers, the lasers are difficult to dissipate heat due to the small integration volume and the integration interval of the lasers, the temperature of the chip is rapidly increased, the stability of the wavelength and power emitted by the lasers is affected, the performance of the lasers is also adversely affected, and therefore the wavelength of each laser needs to be finely adjusted while the initial alignment accuracy of the wavelength is increased as much as possible.
In many laser heat dissipation schemes, temperature control of a semiconductor Cooler (TEC) to maintain stable spectral output of a semiconductor laser is one of the methods currently used, but a conventional temperature control system generally fixes a laser array chip on a whole heat sink, and all laser channels share a whole-chip TEC temperature control system to control the temperature of the whole chip. However, in the REC laser array chip, the wavelength emitted by each laser is different, and the influence of temperature in the working state is complicated. On the laser array chip manufactured based on the REC technology, the distance between each laser array is hundreds of microns, when all lasers work simultaneously, due to a dense integrated structure, heat generated by the lasers is difficult to dissipate in time, and due to different set wavelengths of each laser, heat generation is different, so that the output wavelength of each laser drifts to different degrees. The conventional temperature control system can only control the temperature of the whole laser chip within a certain range, but the wavelength intervals among the laser channels are not equal any more, so that a series of problems such as crosstalk and the like can be caused. The output wavelength of the multi-channel laser light source is required to meet the ITU-T standard, that is, the wavelength interval of each channel is required to be strict and accurate, so that the output wavelength of each laser light source is required to be accurately controlled, which requires that each laser channel is subjected to temperature control and wavelength fine adjustment respectively. In addition, because the heat transfer path between the cold source or heat source for controlling the temperature and the semiconductor laser is relatively long, the response time is relatively slow, the semiconductor laser array chip based on the REC technology has poor refrigeration effect, and the laser emitting wavelength has large drift error.
The invention with the patent number of CN110098554A discloses a temperature control component and a solid laser with the same, wherein the temperature control component comprises a control structure and at least two TECs, the TECs are provided with at least one master TEC, the rest are slave TECs, the master TEC is directly and electrically connected with the control structure, and the slave TECs are electrically connected with the master TEC so that the master TEC passively controls the slave TECs under the control of the control structure. The invention solves the problems that in the prior art, when a plurality of semiconductor refrigerators are arranged, a plurality of controllers are required to be arranged, so that the complexity and the control difficulty of the whole equipment are increased, but the slave TEC and the master TEC must work synchronously.
The utility model with the patent number CN206992473U discloses a temperature control device for a multi-path integrated ROF radio frequency optical fiber transmission and emission module, which comprises a first-stage semiconductor refrigerator, a second-stage semiconductor refrigerator and a metal heat sink. The utility model discloses a relay mode through two-stage semiconductor refrigeration only has realized the temperature regulation of bigger span, can not carry out alone regulation and control to a plurality of laser instrument units in the semiconductor laser array chip based on REC technique, also is not applicable to the semiconductor laser array chip of REC technical preparation.
The invention with the patent number of CN104298278A discloses a laser temperature control system based on PD, wherein a temperature measurement subsystem indirectly obtains the temperature of a laser through an NTC, converts the temperature of the laser into an electric signal, compares the electric signal with a set value and inputs the electric signal into a temperature control subsystem; the temperature control subsystem controls the temperature by adopting an intelligent control algorithm; the temperature control actuator subsystem amplifies the power of the temperature control signal, drives the actuator TEC to work, and heats or refrigerates the laser heat sink; the temperature feedback subsystem converts output light current of a PD (photodiode) integrated in the laser into a voltage signal and feeds the voltage signal back to the input end; and the temperature display subsystem realizes the display of the laser temperature. Similarly, the invention does not have the function of individually regulating and controlling a plurality of laser units in the semiconductor laser array chip based on the REC technology.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides the REC semiconductor laser array wavelength control system, which enables each laser channel to output light beams with stable wavelength by respectively carrying out coarse adjustment and fine adjustment on the temperature outside and inside a laser array chip, thereby realizing the accurate control on the wavelength interval.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, an embodiment of the present invention provides an REC semiconductor laser array wavelength control system, configured to adjust a temperature of each laser unit of a laser array chip manufactured based on an REC technology, where the wavelength control system includes an integrated TEC, a temperature measurement circuit, a temperature error amplifier, a PID compensation circuit, a TEC drive circuit, M independent TECs, M thermistors, and M heat sinks; m is a positive integer greater than or equal to 2;
the integrated TEC, the temperature measuring circuit, the temperature error amplifier, the PID compensating circuit and the TEC driving circuit are arranged outside the laser array chip structure;
the independent TEC, the thermistor and the heat sink are arranged in the laser array chip structure and correspond to the laser units one by one; the thermistor is positioned above the laser unit; the independent TEC is deposited on a substrate of the laser array chip and is connected with the lower surface of the laser unit through a corresponding heat sink;
the temperature measuring circuit is connected with the thermistor and converts the real-time working temperature of the corresponding laser unit sensed by the thermistor into a corresponding working temperature electric signal; the temperature error amplifier performs differential processing on the working temperature electric signal of each laser unit output by the temperature measuring circuit and a preset target temperature electric signal of a corresponding channel to obtain a temperature error signal of each laser unit, and amplifies the temperature error signal;
the PID compensation circuit controls the TEC driving circuit to work according to the M temperature error signals output by the temperature error amplifier, so that the TEC driving circuit applies voltage to the integrated TEC arranged on the bottom surface of the substrate, the integrated TEC is adopted to carry out coarse temperature adjustment on the whole laser array chip, then voltage is applied to the independent TEC of the laser unit which does not meet the target temperature electric signal, and the independent TEC is adopted to carry out fine temperature adjustment on the corresponding laser unit.
Further, the thermistor and the heat sink are respectively bonded with the upper surface and the lower surface of the laser unit, and are electrically connected with the corresponding bonding surfaces.
Further, the sizes of the laser unit, the thermistor, the heat sink and the independent TEC are in the same order of magnitude, and the size of the laser is smaller than the sizes of the thermistor, the heat sink and the independent TEC.
Further, the laser unit has a lateral dimension of 150 microns, the heat sink and the free standing TEC have a lateral dimension of 200 microns, and the thermistor has a lateral dimension of 180 microns.
Further, the spacing between two adjacent laser units of the laser array is larger than the lateral dimension of each laser unit itself.
Further, the heat sink is made of pure copper, copper alloy, pure silver or silver alloy.
In a second aspect, an embodiment of the present invention provides a manufacturing method of a REC semiconductor laser array wavelength control system, where the manufacturing method includes the following steps:
s1, evaporating or printing M independent TECs on the upper surface of the Si substrate at intervals, printing two corresponding first electrodes at two ends of each independent TEC, and connecting the two first electrodes with an external circuit;
s2, placing the M heat sinks above the M independent TECs in a one-to-one correspondence manner;
s3, depositing M laser units manufactured by using REC technology above M heat sinks in a one-to-one correspondence manner to form a laser array, generating a thermistor above each laser unit by adopting an evaporation or printing manner, and printing two corresponding second electrodes at two ends of the thermistor;
s4, connecting each independent TEC with a TEC driving circuit by adopting a first electrode, and connecting each thermistor with a temperature measuring circuit by adopting a second electrode;
and S5, packaging the laser array by using the tube shell, and placing the packaged laser chip on the integrated TEC.
Further, the manufacturing method further comprises the following steps:
and the thermistor is electrically connected with the upper contact surface of the laser unit, and the heat sink is electrically connected with the lower contact surface of the laser unit in a metal spraying mode.
In a third aspect, an embodiment of the present invention provides a wavelength control method for a REC semiconductor laser array wavelength control system, where the wavelength control method includes the following steps:
a1, converting the real-time working temperature of the corresponding laser unit sensed by each thermistor into a working temperature electric signal;
a2, carrying out differential processing on the working temperature electric signal of each laser unit and a preset target temperature electric signal of a corresponding channel to obtain a temperature error signal of each laser unit, and amplifying the temperature error signal;
and A3, controlling the TEC drive circuit to work according to the M temperature error signals, so that the TEC drive circuit applies voltage to the integrated TEC arranged on the bottom surface of the substrate, roughly adjusts the temperature of the whole laser array chip by adopting the integrated TEC, applies voltage to the independent TEC of the laser unit which does not meet the target temperature electric signal, and finely adjusts the temperature of the corresponding laser unit by adopting the independent TEC.
Further, the independent TEC cools or heats the corresponding laser unit according to the control instruction of the TEC drive circuit.
On the basis of analyzing that a Distributed Feedback (DFB) laser array chip manufactured based on an REC technology meets the requirement of stable temperature control of each channel wavelength, the invention designs a laser precise temperature control system, adopts a linear optimized bridge circuit to measure the temperature, adopts a PID compensation circuit to perform feedback control, and adopts a TEC driving circuit to control the voltage and the current directions of an input integral TEC and an independent TEC, thereby realizing the rough temperature adjustment of the integral TEC to the laser chip and the independent temperature fine adjustment of the independent TEC to each laser, greatly inhibiting the drift of each emission wavelength and providing guarantee for the stabilization of the output wavelength of the laser. Besides, the temperature control system is also suitable for other places requiring precise temperature control, and the design method can also provide reference for the design of other temperature control systems.
The invention has the beneficial effects that:
(1) according to the invention, the integrated TEC outside the chip and the independent TEC inside the chip are used for respectively carrying out the comprehensive regulation and control of coarse regulation and fine regulation on the temperature of the laser unit, so that the stability of the emission wavelength of the laser is ensured, and the wavelength interval between each channel is controlled within a certain range.
(2) On the basis of the temperature control method of the integral type TEC on the traditional laser chip, the invention encapsulates the heat sink and the control part of the temperature control system in the chip, and precisely controls the temperature of the heat source, thereby reducing the heat transfer path and reducing the response time of the laser.
(3) In the laser array designed by the invention, the distance between each laser structure is larger than the transverse size of the laser structure, and the temperature of the lasers is changed in a gradient manner, so that the sparse array structure can reduce transverse heat transmission among the lasers, and the chip can be processed more easily, and the heat dissipation effect is better.
(4) The temperature control system can control the internal temperature of the laser more sensitively, and can respectively carry out micro-adjustment on the temperature and the wavelength of a plurality of laser units on one chip, thereby meeting the requirement of the temperature control precision of the laser and improving the control precision and the working reliability. And a heat sink and an independent TEC control plate with the volume equivalent to that of the laser unit are used, so that the volume of the REC laser array chip can be controlled in the micron order, and the application range and the field of the REC laser array chip are widened.
Drawings
Fig. 1 is a schematic structural diagram of a REC semiconductor laser array wavelength control system according to an embodiment of the present invention.
Fig. 2 is a schematic diagram of a temperature control principle of a REC semiconductor laser array wavelength control system according to an embodiment of the present invention.
Fig. 3 shows the wavelength shift of the laser array chip in the operating state when the temperature control system is not used.
Fig. 4 shows the wavelength shift of the laser array chip in the operating state when only the conventional one-piece free-standing TEC is used for temperature control.
Fig. 5 shows the wavelength drift of the laser array chip in the working state when the integrated TEC and the free-standing TEC designed by the present invention are used for dual temperature control.
The reference numbers illustrate: 1-thermistor, 2-laser bottom, 3-heat sink, 4-independent TEC, 5-laser array chip substrate, and 6-integrated TEC.
Detailed Description
The present invention will now be described in further detail with reference to the accompanying drawings.
It should be noted that the terms "upper", "lower", "left", "right", "front", "back", etc. used in the present invention are for clarity of description only, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not limited by the technical contents of the essential changes.
Example one
Fig. 1 is a schematic structural diagram of a REC semiconductor laser array wavelength control system according to an embodiment of the present invention. The wavelength control system is used for adjusting the temperature of each laser unit 2 of a laser array chip manufactured based on an REC technology, and comprises an integral TEC6, a temperature measuring circuit, a temperature error amplifier, a PID compensation circuit, a TEC driving circuit, M independent TECs 4, M thermistors 1 and M heat sinks 3; m is a positive integer greater than or equal to 2.
The integrated TEC6, the temperature measuring circuit, the temperature error amplifier, the PID compensation circuit and the TEC driving circuit are arranged outside the laser array chip structure.
The independent TEC4, the thermistor 1 and the heat sink 3 are arranged in the laser array chip structure and correspond to the laser units 2 one by one; the thermistor 1 is positioned above the laser unit 2; the free standing TEC4 is deposited on the substrate 5 of the laser array chip and is connected to the lower surface of the associated laser unit 2 by a corresponding heat sink 3.
The temperature measuring circuit is connected with the thermistor 1 and converts the real-time working temperature of the corresponding laser unit 2 sensed by the thermistor 1 into a corresponding working temperature electric signal; the temperature error amplifier performs differential processing on the working temperature electrical signal of each laser unit 2 output by the temperature measuring circuit and a preset target temperature electrical signal of a corresponding channel to obtain a temperature error signal of each laser unit 2, and amplifies the temperature error signal.
The PID compensation circuit controls the TEC drive circuit to work according to M temperature error signals output by the temperature error amplifier, so that the TEC drive circuit applies voltage to the integrated TEC6 arranged on the bottom surface of the substrate 5, the integrated TEC6 is adopted to perform coarse temperature adjustment on the whole laser array chip, then voltage is applied to the independent TEC4 of the laser unit 2 which does not meet the target temperature electric signal, and the independent TEC4 is adopted to perform fine temperature adjustment on the corresponding laser unit 2.
Description of internal structure of laser array chip
The laser array chip of the embodiment is manufactured by adopting an REC technology. In the semiconductor laser structure, the REC technology is utilized to realize that the channel wavelength can be changed only by changing the period of the sampling photoetching plate under the condition of not changing the period of the uniform seed grating, and the high precision is realized when the wavelength is controlled to relatively change.
Inside the laser array chip manufactured based on the REC technology, besides the laser unit 2, a thermistor 1, a heat sink 3 and a free-standing TEC4 are included.
Corresponding connecting electrodes are arranged at two ends of the thermistor 1 and the heat sink 3, or the thermistor 1 and the heat sink 3 are respectively bonded with the upper surface and the lower surface of a single laser, and are electrically connected with each other on the bonding surface, so that the chip is convenient to contact with an external circuit of the chip. The thermistor 1 with the negative temperature coefficient is used as a temperature sensor to acquire the real-time temperature of the laser, and the optimal linear relation can be approached in a specified temperature range by connecting the compensation resistors in series in a certain temperature range. The relation between the real-time voltage value of the thermistor 1 in the temperature measuring circuit and the real-time temperature of the laser can be established by giving the thermistor 1 the determined reference voltage in advance and combining the known resistance value of the thermistor 1 at a certain temperature. The free-standing TEC4 is placed under the heat sink 3, and the free-standing TEC4 is caused to refrigerate by the voltage and current directions in the free-standing TEC4, so that the temperature of the laser is controlled. Preferably, the heat sink 3 serves as a support and heat conducting carrier for the laser, and a material with high thermal conductivity, such as copper, tungsten-copper composite material, silver and silver alloy material, etc., should be selected as much as possible.
Illustratively, the size of the laser unit 2, the thermistor 1, the heat sink 3, and the free standing TEC4 are on the same order of magnitude, and the size of the laser is smaller than the size of the thermistor 1, the heat sink 3, and the free standing TEC 4. For example, the laser unit 2 has a lateral dimension of 150 microns, the heat sink 3 and free standing TEC4 have a lateral dimension of 200 microns, and the thermistor 1 has a lateral dimension of 180 microns.
The spacing between two adjacent laser units 2 of the laser array is larger than the lateral dimension of each laser unit 2 itself. If the lateral dimensions of the laser structures are 150 microns and the spacing between the free standing TECs 4 under each laser is set to 200 microns, the lateral spacing of each laser structure can be up to 250 microns, which is a relatively sparse laser array structure to facilitate heat dissipation and processing of the chip.
Principle description of external structure (temperature control system) of laser array chip
The external structure of the laser array chip of the embodiment includes a temperature measurement circuit, a temperature error amplifier, a PID compensation circuit and a TEC drive circuit, and the components of the external structure, together with the thermistor 1 and the independent TEC4, form a temperature control system of the laser array chip.
The temperature measuring circuit is connected with the thermistor 1 in the chip, and converts the real-time working temperature of the single laser unit 2 collected by the thermistor 1 into a corresponding working temperature electric signal. The temperature error amplifier performs differential processing on the real-time working temperature electric signal of each laser unit 2 and a preset working temperature standard signal of each channel to obtain a temperature error signal and amplifies the temperature error signal. The PID compensation circuit receives the amplified temperature error signal, and the control signal output to the TEC is regulated through the PID compensation network.
The TEC driving circuit firstly controls the voltage and the current direction flowing through the integrated TEC6, so as to control the heating and cooling of the laser array chip and carry out coarse temperature adjustment on the laser chip. And then the TEC driving circuit controls the voltage and the current direction flowing through the independent TEC4 in the semiconductor laser array chip so as to control the independent TEC4 to heat and cool the laser array chip and perform temperature fine adjustment on the laser chip. When the real-time voltage value of the thermistor 1 in the temperature measuring circuit is equal to the theoretical voltage value of the thermistor 1 at the target temperature, the temperature of the laser is considered to reach the set target temperature value, and therefore the temperature fine adjustment of each laser is achieved.
Example two
The embodiment of the invention provides a manufacturing method of an REC semiconductor laser array wavelength control system, which comprises the following steps:
s1, M independent TECs 4 are evaporated or printed on the upper surface of the Si substrate 5 at intervals, two corresponding first electrodes are printed at two ends of each independent TEC4, and the two first electrodes are connected with an external circuit.
S2, the M heat sinks 3 are placed above the M independent TECs 4 in a one-to-one correspondence mode, and the laser is supported and conducted. Because the heat sink 3 of the invention has much smaller volume than the heat sink 3 of the traditional laser, the heat sink 3 material with high heat conductivity should be selected as much as possible, and the materials such as pure copper, copper alloy, pure silver, silver alloy and the like can be selected.
And S3, depositing M laser units 2 manufactured by using the REC technology above the M heat sinks 3 in a one-to-one correspondence manner to form a laser array, generating a thermistor 1 above each laser unit 2 by adopting an evaporation or printing manner, and printing two corresponding second electrodes at two ends of the thermistor 1.
The size of the laser unit 2 is smaller than the size of the thermistor 1, heat sink 3, free standing TEC4, but the size of the laser unit 2 is in the same order of magnitude as the size of the thermistor 1, heat sink 3, free standing TEC 4.
The contact surfaces of the thermistor 1 and the heat sink 3 with the laser can also be electrically connected through metal spraying, so that the connection with an external temperature control circuit of the chip is facilitated.
The same procedure is repeated for a plurality of laser units 2 to form a laser array. The pitch between each laser unit 2 is larger than the pitch between the lasers in the conventional laser array chip. If the lateral dimension of the laser structure is 150 microns, the spacing between the free-standing TECs 4 under each laser is set to 200 microns, and the lateral spacing of each laser structure can reach 250 microns, so that the sparse laser array structure facilitates heat dissipation and processing of the chip.
And S4, after the bonding structure of each laser unit 2, the thermistor 1, the heat sink 3 and the independent TEC4 is manufactured, connecting each laser unit 2 with a circuit outside the chip through wires. The temperature control principle of each laser channel is the same, so that a plurality of bonded laser units 2 can share one temperature control system.
S5, after the bonding and wire-bonding steps of each laser unit 2 are completed, the laser array is packaged by using the package, and the packaged laser chip is placed on the integrated TEC 6.
EXAMPLE III
The embodiment of the invention provides a wavelength control method of an REC semiconductor laser array wavelength control system, which comprises the following steps:
a1, converting the real-time working temperature of the corresponding laser unit 2 sensed by each thermistor 1 into an electric working temperature signal.
A2, performing difference processing on the working temperature electrical signal of each laser unit 2 and a preset target temperature electrical signal of a corresponding channel to obtain a temperature error signal of each laser unit 2, and amplifying the temperature error signal.
A3, controlling the TEC drive circuit to work according to the M temperature error signals, enabling the TEC drive circuit to firstly apply voltage to the integrated TEC6 arranged on the bottom surface of the substrate 5, adopting the integrated TEC6 to carry out coarse temperature adjustment on the whole laser array chip, then applying voltage to the independent TEC4 of the laser unit 2 which does not meet the target temperature electric signal, and adopting the independent TEC4 to carry out fine temperature adjustment on the corresponding laser unit 2.
Taking an 8-channel laser array chip with 200GHz intervals as an example, the thermistor 1 above each semiconductor laser senses the real-time working temperature of each laser respectively, converts the real-time working temperature into an electric signal and transmits the electric signal to the temperature measuring circuit respectively. The temperature error amplifier carries out difference processing on the working temperature electric signal of each laser and a preset temperature standard value of each channel to obtain a plurality of temperature error values and amplifies the temperature error values. And the PID compensation circuit receives the amplified temperature error signal and controls the TEC drive circuit of the semiconductor refrigerator. The TEC driving circuit firstly controls the integrated TEC6 through the voltage difference circuit, at this time, the overall temperature of the laser chip is reduced, but the temperature change of each individual laser is complex, and the wavelength may have a non-uniform drift phenomenon. The drive circuitry continues to exert control over each of the free standing TECs 4 on the lasers, and the free standing TEC4 will be driven to cool if the temperature of the laser array chip is above the set target temperature. If the temperature of the laser array chip is below the set target temperature, the free standing TEC4 will be driven to heat up.
Therefore, when the laser works in a higher power state, as long as the junction temperature of the laser array chip is different from the set target temperature, the chip temperature can be stabilized in a range suitable for the laser to work through the closed-loop control of the temperature control circuit, and the performance and the service life of the laser can be ensured. After the laser array chip obtains stable wavelength output, the laser can be used in subsequent practical application.
As shown in fig. 3, when the temperature control system is not used, the wavelength drift of the laser array chip in the operating state is severe, and the wavelength drift of each laser array is different. When the laser starts to work, the generated heat cannot be timely dissipated, the temperature of the active area of the laser rises, the wavelength can be red-shifted, namely, the wavelength moves towards the long wavelength direction, the wavelength of the first channel moves by 0.14nm, the wavelengths of other channels are red-shifted successively until the wavelength of the eighth channel moves by 0.8 nm. The separation of the first channel from the second channel is increased from the standard 1.6nm to 1.61 nm. Until the wavelength separation of the seventh channel from the eighth channel increases to 1.8nm, the corresponding frequency increases from the standard 200GHz to 223 GHz.
As shown in fig. 4, when only the conventional monolithic TEC temperature control system is used, the laser array chip still has a slight wavelength shift in the operating state, and the wavelength shift of each laser array is different from each other. Until the wavelength separation of the seventh channel from the eighth channel increases to 1.7nm, the corresponding frequency increases from the standard 200GHz to 212 GHz.
As shown in fig. 5, based on the conventional monolithic TEC temperature control system, when the free-standing TEC temperature control system designed by the present invention is used, the independent TEC structure can individually fine-tune the temperature of each laser, the laser array chip can substantially ensure stable wavelength output in the operating state, and the wavelength interval of each channel is strictly maintained at 1.6nm, that is, the standard 200GHz frequency interval.
In summary, the temperature control structure and system of the DFB laser array chip manufactured based on the REC technology according to the present invention can accurately stabilize the real-time operating temperature of each laser within the preset temperature range, thereby greatly suppressing the drift of each emission wavelength, and providing a guarantee for stabilizing the output wavelength of the laser.
The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention.
Claims (8)
1. A wavelength control system of an REC semiconductor laser array is used for adjusting the temperature of each laser unit of a laser array chip manufactured based on an REC technology, and is characterized in that the wavelength control system comprises an integrated TEC, a temperature measuring circuit, a temperature error amplifier, a PID compensation circuit, a TEC driving circuit, M independent TECs, M thermistors and M heat sinks; m is a positive integer greater than or equal to 2;
the integrated TEC, the temperature measuring circuit, the temperature error amplifier, the PID compensating circuit and the TEC driving circuit are arranged outside the laser array chip structure;
the independent TEC, the thermistor and the heat sink are arranged in the laser array chip structure and correspond to the laser units one by one; the thermistor is positioned above the laser unit; the independent TEC is deposited on a substrate of the laser array chip and is connected with the lower surface of the laser unit through a corresponding heat sink;
the temperature measuring circuit is connected with the thermistor and converts the real-time working temperature of the corresponding laser unit sensed by the thermistor into a corresponding working temperature electric signal; the temperature error amplifier performs differential processing on the working temperature electric signal of each laser unit output by the temperature measuring circuit and a preset target temperature electric signal of a corresponding channel to obtain a temperature error signal of each laser unit, and amplifies the temperature error signal;
the PID compensation circuit controls the TEC driving circuit to work according to the M temperature error signals output by the temperature error amplifier, so that the TEC driving circuit applies voltage to the integrated TEC arranged on the bottom surface of the substrate, the integrated TEC is adopted to carry out coarse temperature adjustment on the whole laser array chip, then voltage is applied to the independent TEC of the laser unit which does not meet the target temperature electric signal, and the independent TEC is adopted to carry out fine temperature adjustment on the corresponding laser unit.
2. The REC semiconductor laser array wavelength control system of claim 1, wherein the thermistor and the heat sink are bonded to the upper surface and the lower surface of the laser unit respectively and form an electrical connection at the corresponding bonding surfaces.
3. A REC semiconductor laser array wavelength control system according to claim 1, wherein the size of the laser unit, thermistor, heat sink, free standing TEC is in the same order of magnitude and the size of the laser is smaller than the size of the thermistor, heat sink, free standing TEC.
4. A REC semiconductor laser array wavelength control system according to claim 1, wherein the spacing between two adjacent laser units of the laser array is greater than the lateral dimension of each laser unit itself.
5. The REC semiconductor laser array wavelength control system of claim 1, wherein the heat sink is made of pure copper, copper alloy, pure silver, or silver alloy.
6. A method of fabricating a wavelength control system based on an REC semiconductor laser array as claimed in any one of claims 1 to 5, said method of fabricating comprising the steps of:
s1, evaporating or printing M independent TECs on the upper surface of the Si substrate at intervals, printing two corresponding first electrodes at two ends of each independent TEC, and connecting the two first electrodes with an external circuit;
s2, placing the M heat sinks above the M independent TECs in a one-to-one correspondence manner;
s3, depositing M laser units manufactured by using REC technology above M heat sinks in a one-to-one correspondence manner to form a laser array, generating a thermistor above each laser unit by adopting an evaporation or printing manner, and printing two corresponding second electrodes at two ends of the thermistor;
s4, connecting each independent TEC with a TEC driving circuit by adopting a first electrode, and connecting each thermistor with a temperature measuring circuit by adopting a second electrode;
and S5, packaging the laser array by using the tube shell, and placing the packaged laser chip on the integrated TEC.
7. A wavelength control method based on the REC semiconductor laser array wavelength control system as claimed in any one of claims 1 to 5, characterized in that the wavelength control method comprises the following steps:
a1, converting the real-time working temperature of the corresponding laser unit sensed by each thermistor into a working temperature electric signal;
a2, carrying out differential processing on the working temperature electric signal of each laser unit and a preset target temperature electric signal of a corresponding channel to obtain a temperature error signal of each laser unit, and amplifying the temperature error signal;
and A3, controlling the TEC drive circuit to work according to the M temperature error signals, so that the TEC drive circuit applies voltage to the integrated TEC arranged on the bottom surface of the substrate, roughly adjusts the temperature of the whole laser array chip by adopting the integrated TEC, applies voltage to the independent TEC of the laser unit which does not meet the target temperature electric signal, and finely adjusts the temperature of the corresponding laser unit by adopting the independent TEC.
8. The wavelength control method of the REC semiconductor laser array wavelength control system of claim 7, wherein the free-standing TEC cools or heats the corresponding laser unit according to the control command of the TEC drive circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210030664.7A CN114374145B (en) | 2022-01-12 | 2022-01-12 | REC semiconductor laser array wavelength control system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210030664.7A CN114374145B (en) | 2022-01-12 | 2022-01-12 | REC semiconductor laser array wavelength control system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114374145A true CN114374145A (en) | 2022-04-19 |
| CN114374145B CN114374145B (en) | 2023-09-29 |
Family
ID=81144651
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210030664.7A Active CN114374145B (en) | 2022-01-12 | 2022-01-12 | REC semiconductor laser array wavelength control system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114374145B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0555709A (en) * | 1991-08-29 | 1993-03-05 | Nec Corp | Cooling type semiconductor laser array module |
| US5608568A (en) * | 1994-04-11 | 1997-03-04 | The Johns Hopkins University | Thin film vanadium oxide spatial light modulators and methods |
| CN106019620A (en) * | 2016-07-01 | 2016-10-12 | 中国科学院光电研究院 | Device for inhibiting laser speckles and laser projection device |
| CN111370993A (en) * | 2020-04-15 | 2020-07-03 | 广东鸿芯科技有限公司 | Semiconductor laser device with constant temperature control function and manufacturing method thereof |
| CN111490457A (en) * | 2020-04-22 | 2020-08-04 | 南京鼎芯瑞科股权投资合伙企业(有限合伙) | Refrigeration-free tunable semiconductor laser based on multi-wavelength array and preparation method thereof |
| CN211700276U (en) * | 2020-04-15 | 2020-10-16 | 广东鸿芯科技有限公司 | Photoelectric module assembly with constant temperature control function |
| CN111884030A (en) * | 2020-06-28 | 2020-11-03 | 南京大学 | Quick tuning control system based on series-parallel array laser |
| CN113725347A (en) * | 2021-08-31 | 2021-11-30 | 中国科学院半导体研究所 | Aliasing integrated packaging device and packaging method of optoelectronic chip |
-
2022
- 2022-01-12 CN CN202210030664.7A patent/CN114374145B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0555709A (en) * | 1991-08-29 | 1993-03-05 | Nec Corp | Cooling type semiconductor laser array module |
| US5608568A (en) * | 1994-04-11 | 1997-03-04 | The Johns Hopkins University | Thin film vanadium oxide spatial light modulators and methods |
| CN106019620A (en) * | 2016-07-01 | 2016-10-12 | 中国科学院光电研究院 | Device for inhibiting laser speckles and laser projection device |
| CN111370993A (en) * | 2020-04-15 | 2020-07-03 | 广东鸿芯科技有限公司 | Semiconductor laser device with constant temperature control function and manufacturing method thereof |
| CN211700276U (en) * | 2020-04-15 | 2020-10-16 | 广东鸿芯科技有限公司 | Photoelectric module assembly with constant temperature control function |
| CN111490457A (en) * | 2020-04-22 | 2020-08-04 | 南京鼎芯瑞科股权投资合伙企业(有限合伙) | Refrigeration-free tunable semiconductor laser based on multi-wavelength array and preparation method thereof |
| CN111884030A (en) * | 2020-06-28 | 2020-11-03 | 南京大学 | Quick tuning control system based on series-parallel array laser |
| CN113725347A (en) * | 2021-08-31 | 2021-11-30 | 中国科学院半导体研究所 | Aliasing integrated packaging device and packaging method of optoelectronic chip |
Non-Patent Citations (1)
| Title |
|---|
| 倪屹: "基于REC技术的可调谐DFB激光器阵列设计与测试", 《中国激光》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114374145B (en) | 2023-09-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8089995B2 (en) | Structures and methods for adjusting the wavelengths of lasers via temperature control | |
| EP1804348B1 (en) | Optical assembly comprising multiple semiconductor optical devices and an active cooling device | |
| US7295582B2 (en) | Thermo-optic tunable laser apparatus | |
| US6724797B2 (en) | External cavity laser with selective thermal control | |
| EP2044663B1 (en) | Misalignment prevention in an external cavity laser having temperature stabilistion of the resonator and the gain medium | |
| CN111490457A (en) | Refrigeration-free tunable semiconductor laser based on multi-wavelength array and preparation method thereof | |
| US6807208B2 (en) | Laser module | |
| JP2018163926A (en) | Optical transmission module, optical module, optical transmission device, and manufacturing method thereof | |
| EP1265379A2 (en) | Wavelength-stabilised optical transmitter for WDM systems | |
| US20090059979A1 (en) | Optical transmission module and optical transmission system | |
| CN209766846U (en) | temperature control assembly and solid laser with same | |
| JP2003078088A (en) | Mounting device for thermoelectric module and method for controlling temperature thereof | |
| CN114374145B (en) | REC semiconductor laser array wavelength control system | |
| US6829263B1 (en) | Semiconductor laser | |
| US6837059B2 (en) | Temperature adjustment device and laser module | |
| US20030067949A1 (en) | Optical module, transmitter and WDM transmitting device | |
| US6762938B2 (en) | Apparatus and method for providing auxiliary cooling and thermal stability to an opto-electronic component | |
| JP2001244545A (en) | Semiconductor laser module | |
| JP5088866B2 (en) | Temperature controller for wavelength locker, wavelength locker and optical module | |
| JP5005421B2 (en) | Temperature controller for wavelength locker, wavelength locker and optical module | |
| CN110098554A (en) | Temperature-controlling module and solid state laser with it | |
| US6724784B2 (en) | Optical wavelength locker module having a high thermal conductive material | |
| EP3675295A1 (en) | Laser assemblies | |
| JP2003273440A (en) | Laser module | |
| JP2004134776A (en) | Temperature-regulating device and laser module |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |