CN115166912B - Micro-ring wavelength division multiplexing optical transmitter, optical receiver, temperature control debugging method and optical transceiver - Google Patents

Abstract

The invention relates to a micro-ring wavelength division multiplexing optical transmitter, an optical receiver, a temperature control debugging method and an optical transceiver, which are used for solving the technical problems that the refractive index changes and the process errors are caused by heat generated in the environment temperature change and the modulation process of the existing optical transmitter and optical receiver, and the resonance peak is offset to reduce the wavelength division multiplexing effect. The optical transmitter comprises a micro-ring modulator and a first temperature control adjusting unit, and the debugging method comprises the following steps: 1. setting a first annular waveguide radius; 2. acquiring the resistance value of the adjustable resistor; 3. adjusting the first heater to meet V' _i ≤V′ _0i . The optical receiver comprises a micro-ring filter and a second temperature control adjusting unit, and the debugging method comprises the following steps: 1. acquiring an initial reference voltage; 2. adjusting the second heater to minimize the output optical power of the second linear waveguide; 3. and adjusting the second heater and the reference voltage to realize the filtering of the corresponding wavelength. The optical transceiver comprises the optical transmitter and the optical receiver.

Description

Micro-ring wavelength division multiplexing optical transmitter, optical receiver, temperature control debugging method and optical transceiver

Technical Field

The invention relates to a wavelength division multiplexing optical transmitter and a wavelength division multiplexing optical receiver and a temperature control adjustment method thereof, and in particular to a micro-ring wavelength division multiplexing optical transmitter, an optical receiver and a temperature control debugging method and an optical transceiver.

Background technique

With the development of Internet technology and the advent of the big data era, the rise of technologies such as cloud computing, cloud storage, and artificial intelligence, the demand for communication capacity from all walks of life is increasing. According to statistics, the number of data centers around the world has doubled in the past decade, and Internet business data has increased more than 10 times.

The wavelength division multiplexing system is based on the principle that light of different wavelengths does not interfere with each other. Through a multiplexer, light of different wavelengths can carry different information and be transmitted in the same optical fiber, which expands the existing optical fiber communication channels, improves the efficiency of light carrying information, and greatly expands the communication capacity. The wavelength division multiplexing system based on silicon-based integrated chips is currently the design method with the most commercial potential. Because of its CMOS compatibility, silicon-based integrated chips can be mass-produced through semiconductor production lines, thereby reducing production costs.

The silicon-based integrated platform has a high refractive index difference, which is conducive to the realization of large-scale, small-size, high-density device integration. However, the sensitivity of silicon waveguide to temperature changes (thermo-optic coefficient 1.84E-4/℃) makes the wavelength division multiplexing devices on the integrated platform, such as micro-ring resonators, also very sensitive to temperature changes. Changes in ambient temperature and the heat generated during the modulation process will cause changes in the refractive index, resulting in the shift of the resonance peak, thereby reducing the wavelength division multiplexing effect. How to control the temperature of the micro-ring modulator in the optical transmitter and the micro-ring filter in the optical receiver so that the resonance peak remains at the desired position is an urgent problem that needs to be solved.

Summary of the invention

The purpose of the present invention is to solve the technical problems that the refractive index of existing optical transmitters and optical receivers changes due to the heat generated during the ambient temperature change and modulation process, and the process errors existing during processing, which lead to the shift of the resonance peak and the reduction of the wavelength division multiplexing effect. A micro-ring wavelength division multiplexing optical transmitter, optical receiver and temperature control debugging method and optical transceiver are proposed.

The technical solution of the present invention is:

A micro-ring wavelength division multiplexing optical transmitter, which is special in that:

The invention comprises a laser, n micro-ring modulators connected to the laser in sequence, and n first temperature control adjustment units connected to the n micro-ring modulators respectively, wherein n is an integer and n≥1; the emitted light of the laser comprises working light beams of n wavelengths, which respectively correspond to the n micro-ring modulators and the n first temperature control adjustment units, and the working light beam of each wavelength is split into a detection light beam and a light beam to be transmitted; the light beam to be transmitted enters the corresponding micro-ring modulator for transmission, and the detection light beam enters the corresponding first temperature control adjustment unit as a comparison light signal, and the detection light beam accounts for 1%-10% of the working light beam;

The micro-ring modulator comprises a first straight waveguide and a first ring waveguide coupled to the first straight waveguide; n first straight waveguides are connected in sequence;

The first temperature control and adjustment unit includes a first heater, an input signal detector, an output signal detector and a first temperature control circuit which are integrated on the first annular waveguide;

The input signal detector comprises an input photodetector and a fixed value resistor, and the input signal detector is used to detect the detection light beam and generate an input detection signal;

The output signal detector comprises an output photodetector and an adjustable resistor, and the output signal detector is used to detect the light beam in the first annular waveguide and generate an output detection signal;

The first temperature control circuit includes a first comparator, a first operation circuit and a first digital-to-analog converter connected in sequence; the two input ends of the first comparator are respectively connected to the output end of the input signal detector and the output end of the output signal detector, and are used to compare and analyze the input detection signal and the output detection signal; the first operation circuit is used to perform operations based on the comparison and analysis results of the first comparator, and input the operation results to the first digital-to-analog converter, and the first digital-to-analog converter is connected to the first heater, and is used to adjust the temperature of the first heater according to the operation results.

Further, the relationship between the radius of the first ring waveguide of the micro-ring modulator and the corresponding wavelength is: mλ _m =2πr ₁ n _1eff , where m is the resonance order, λ _m is the resonance wavelength of the mth order, r ₁ is the radius of the first ring waveguide, and n _1eff is the effective refractive index of the first ring waveguide;

The waveguide material of the micro-ring modulator is silicon, and the waveguide thickness of the micro-ring modulator is 200nm-1000nm, which can realize wavelength division multiplexing of 1260nm-1360nm or 1530nm-1625nm band.

Further, the input photodetector and the output photodetector are both germanium silicon photodiodes;

The first heater is a titanium nitride heater or a lightly doped silicon resistance heater.

The present invention provides a temperature control debugging method for the above-mentioned micro-ring wavelength division multiplexing optical transmitter, which is special in that it includes the following steps:

A1. Design the radius of the first ring waveguide of each micro-ring modulator so that the resonance peak of the first ring waveguide is shifted to a wavelength band smaller than the corresponding working light beam wavelength;

A2, performing standardized optical modulation amplitude analysis on each micro-ring modulator by adjusting the first heater on each micro-ring modulator;

When the current signal ratio of the maximum value point of the standardized light modulation amplitude curve of the i-th micro-ring modulator changes, it is I _i /I _0i , R ₀ is the resistance value of the fixed resistor set as needed, I _0i is the current value measured by the photodetector PD _0i , V _0i =I _0i ·R ₀ , under the condition of V _0i =V _i , according to I _i /I _0i =R ₀ /R _i , the resistance value of the adjustable resistor is calculated in sequence; i=1…n;

A3, start the wavelength division multiplexing optical transmitter, and simultaneously start the temperature control adjustment system, the input signal detector and the output signal detector; start adjusting the transmission state of the working light beam in the micro-ring modulator from the first micro-ring modulator;

For the i-th micro-ring modulator, the transmission state of the working light beam in the micro-ring modulator is determined according to V′ _0i =I′ _0i ·R ₀ , V′ _i =I′ _i ·R _i , wherein V′ _i is the output voltage after the optical signal in the first ring waveguide of the i-th micro-ring modulator is converted into an electrical signal, and V′ _0i is the input voltage of the i-th micro-ring modulator after the optical signal is converted into an electrical signal;

Based on step A1, at this time V′ _i ＞V′ _0i , the first comparator outputs the comparison signal of V′ _0i and V′ _i to the first operation circuit, the first operation circuit operates the signal and then outputs it to the first digital-to-analog converter, the first digital-to-analog converter adjusts the current loaded on the first heater according to the operation result to heat the micro-ring modulator until V′ _i ≤V′ _0i , and maintains the temperature to make the resonance peak at an ideal position, so as to ensure that the light beam to be transmitted enters the first linear waveguide for transmission;

Then the next micro-ring modulator is adjusted until the adjustment of n micro-ring modulators is completed, so that the light beams to be transmitted in the working light beams of the n micro-ring modulators are transmitted in the first straight waveguide of the micro-ring modulator.

The present invention also provides a micro-ring wavelength division multiplexing optical receiver, which is special in that:

It comprises n micro-ring filters and n second temperature control adjustment units respectively connected to the n micro-ring filters, and the n second temperature control adjustment units are correspondingly connected to n adjustable reference voltages; n is the total number of wavelengths received in the wavelength division multiplexing optical receiver, and n is an integer greater than or equal to 1;

The micro-ring filter comprises a second straight waveguide and a second ring waveguide coupled to the second straight waveguide; n second straight waveguides are connected in sequence;

The second temperature control and adjustment unit includes a second heater, an output signal detection component and a second temperature control circuit which are integrated on the second annular waveguide;

The output signal detection component includes a photodetector, a transimpedance amplifier and a low-pass filter connected in sequence; the photodetector is connected to the second ring waveguide and is used to detect the optical signal in the second ring waveguide; the resistor in the transimpedance amplifier is an adjustable resistor; the output signal detection component is used to generate an output voltage and transmit it to the second temperature control circuit;

The second temperature control circuit includes a second comparator, a second operation circuit and a second digital-to-analog converter connected in sequence; the second comparator is used to receive a reference voltage and an output voltage and perform comparative analysis; the second operation circuit is used to perform calculations based on the comparative analysis results of the second comparator, and input the calculation results to the second digital-to-analog converter. The second digital-to-analog converter is connected to the second heater and is used to adjust the temperature of the second heater based on the calculation results.

Further, the relationship between the radius of the second ring waveguide of the microring filter and the corresponding wavelength is: mλ _m =2πr ₂ n _2eff , where m is the resonance order, λ _m is the resonance wavelength of the mth order, r ₂ is the radius of the second ring waveguide, and n _2eff is the effective refractive index of the second ring waveguide;

The waveguide material of the microring filter is silicon, and the waveguide thickness of the microring filter is 200nm-1000nm, which can realize wavelength division multiplexing of 1260nm-1360nm or 1530nm-1625nm band.

Further, the photodetector is a germanium silicon photodiode;

The second heater is a titanium nitride heater or a lightly doped silicon resistance heater.

The present invention also provides a temperature control debugging method for the micro-ring wavelength division multiplexing optical receiver, which is special in that it includes the following steps:

B1, obtaining an initial reference voltage of each second comparator;

B2, adjusting the second heater integrated on each second ring waveguide to make the resonant wavelength of the microring filter smaller than the input optical signal of the corresponding wavelength, and at the same time, making the n wavelengths enter the n second ring waveguides in the order of small to large or from large to small;

B3, start the micro-ring filter and the second temperature control adjustment unit, and adjust the filtering effect of the micro-ring filter starting from the first micro-ring filter;

B3.1. The filtering effect of the j-th micro-ring filter is adjusted. The optical signal in the j-th micro-ring filter is processed by the output signal detection component to form an output voltage V _j . The second comparator receives the output voltage V _j and the initial reference voltage V′ _j and compares them; j=1…n;

V _j ＜V′ _j , then: step a, adjust the second heater through the second temperature control circuit to increase V _j to V _j1 and V _j1 is greater than V′ _j ; step b, adjust the reference voltage to 2V′ _j , so that V _j1 is less than 2V′ _j ; repeat step a to increase V _j1 to V _j2 and V _j2 is greater than 2V′ _j , repeat step b, adjust the reference voltage to 3V′ _j , so that V _j2 is less than 3V′ _j ; repeat step a and repeat step b until V _jn ＞nV′ _j cannot be achieved by adjusting the second heater; if the voltage adjustment accuracy meets the requirements, use the second heater to maintain the temperature so that the resonance peak is in an ideal position to achieve the corresponding wavelength filtering in the jth microring filter, and execute B3.3; if the voltage adjustment accuracy does not meet the requirements, execute B3.2;

B3.2. Take the median voltage V _M1 of (n-1)V′ _j and nV′ _j , adjust the second heater, and determine the relationship between the output voltage and the median voltage V _M1 :

If the output voltage is greater than the median voltage V _M1 , the median voltage V _M2 of the median voltage V _M1 and nV′ _j is taken, and the second heater is adjusted to determine the relationship between the output voltage and the median voltage V _M2 ; if the output voltage cannot be greater than the median voltage V _M1 , the median voltage V _M3 of (n-1)V′ _j and the median voltage V _M1 is taken, and the second heater is adjusted to determine the relationship between the output voltage and the median voltage V _M3 ;

The median of the reference voltage is taken and judged in sequence until the output voltage cannot be greater than the median voltage and the voltage regulation accuracy meets the requirements, and the second heater is used to maintain the temperature so that the resonance peak is in an ideal position to achieve the corresponding wavelength filtering in the jth microring filter;

Then the next micro-ring filter is adjusted until the adjustment of n micro-ring filters is completed, thereby achieving the corresponding wavelength filtering in the n micro-ring filters.

Furthermore, in step B1, the calculation formula of the initial reference voltage V′ _j is as follows:

V′ _j = (P _j -P _{j loss} ) · R _j · G _j

Wherein, _Pj is the original optical power of the corresponding optical wavelength in the jth microring filter, Pj _loss is the maximum optical power loss value of the corresponding optical wavelength in the jth microring filter, _Rj is the response rate of the photodetector _PDj connected to the jth microring filter, and _Gj is the gain of the transimpedance amplifier connected to the photodetector _PDj .

The present invention also provides a micro-ring wavelength division multiplexing optical transceiver, which is special in that it comprises the above-mentioned micro-ring wavelength division multiplexing optical transmitter and the above-mentioned micro-ring wavelength division multiplexing optical receiver.

Beneficial effects of the present invention:

1. The wavelength division multiplexing optical transmitter provided by the present invention uses fewer detectors and has a smaller system loss. During operation, each micro-ring modulator corresponds to a working light beam of one wavelength and is not subject to interference from different light energies of different wavelengths.

2. The temperature control debugging method of the micro-ring wavelength division multiplexing optical transmitter provided by the present invention adopts a ring-by-ring analysis method for the micro-ring modulator, and detects the input and output signals of a single micro-ring modulator by using a photodetector to reduce the influence of the micro-ring modulator failing to achieve a complete filtering effect and causing part of the wavelength light not to be filtered out on the adjustment.

3. The detector used in the wavelength division multiplexing optical receiver provided by the present invention is based on the detector that the receiving end itself needs to use, and the system loss is small.

4. The temperature control debugging method of the wavelength division multiplexing optical receiver provided by the present invention uses a detector to observe the input and output signals of a single micro-ring modulator through a ring-by-ring analysis method, so that the optical signal is output in sequence according to the wavelength size; during operation, since the reference voltage changes with the output voltage, the response speed is faster; therefore, the temperature control debugging method has the characteristics of fast response speed and low loss.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of a micro-ring wavelength division multiplexing optical transmitter according to the present invention (the laser is not shown in the figure);

FIG2 is a schematic diagram of the temperature control debugging process of the micro-ring wavelength division multiplexing optical transmitter of the present invention;

FIG3 is a schematic diagram of the first principle of standardized optical modulation amplitude analysis of a micro-ring wavelength division multiplexing optical transmitter in Example 1;

FIG4 is a second schematic diagram of the principle of standardized optical modulation amplitude analysis of a micro-ring wavelength division multiplexing optical transmitter in Example 1;

FIG5 is a schematic diagram of the structure of a micro-ring wavelength division multiplexing optical receiver according to the present invention;

FIG. 6 is a schematic diagram of the temperature control debugging process of the micro-ring wavelength division multiplexing optical receiver of the present invention.

The reference numerals are as follows:

101-first straight waveguide, 102-first ring waveguide, 103-first heater, 104-output photodetector, 105-input photodetector, 106-first comparator, 107-first operational circuit, 108-first digital-to-analog converter, 201-second straight waveguide, 202-second ring waveguide, 203-second heater, 204-photodetector, 205-transimpedance amplifier, 206-low-pass filter, 207-second comparator, 208-second operational circuit, 209-second digital-to-analog converter, 210-receiving device.

Detailed ways

Example 1

Referring to FIG. 1 , this embodiment provides a micro-ring wavelength division multiplexing optical transmitter, which includes a laser (not shown in the figure), n micro-ring modulators connected to the laser in sequence, and n first temperature control adjustment units respectively connected to the n micro-ring modulators, where n is an integer and n≥1; the emitted light of the laser includes working light beams of n wavelengths, which respectively correspond to the n micro-ring modulators and the n first temperature control adjustment units, and the working light beam of each wavelength is split into a detection light beam and a light beam to be transmitted; the light beam to be transmitted enters the corresponding micro-ring modulator for transmission, and the detection light beam enters the corresponding first temperature control adjustment unit as a comparison light signal, and the detection light beam accounts for 1%-10% of the working light beam.

The micro-ring modulator comprises a first linear waveguide 101 and a first ring waveguide 102 coupled to the first linear waveguide 101; n first linear waveguides 101 are connected in sequence; the relationship between the radius of the first ring waveguide 102 of the micro-ring modulator and the corresponding wavelength is: mλ _m =2πr ₁ n _1eff , wherein m is the resonance order, λ _m is the resonance wavelength of the mth order, r ₁ is the radius of the first ring waveguide 102, and n _1eff is the effective refractive index of the first ring waveguide 102; the waveguide material of the micro-ring modulator is silicon, and the waveguide thickness of the micro-ring modulator is 200nm-1000nm, which can realize wavelength division multiplexing of 1260nm-1360nm or 1530nm-1625nm band.

The first temperature control and adjustment unit includes a first heater 103, an input signal detector, an output signal detector and a first temperature control circuit integrated on the first ring waveguide 102; specifically, the first heater 103 is a titanium nitride heater or a lightly doped silicon resistance heater; the input signal detector includes an input photodetector 105 and a fixed resistor, and the input signal detector is used to detect a detection light beam and generate an input detection signal; the output signal detector includes an output photodetector 104 and an adjustable resistor, and the output signal detector is used to detect a light beam in the first ring waveguide 102 and generate an output detection signal; the input photodetector 105 and the output photodetector 104 are germanium silicon photodiodes.

The first temperature control circuit includes a first comparator 106, a first operation circuit 107 and a first digital-to-analog converter 108 connected in sequence; the two input ends of the first comparator 106 are respectively connected to the output end of the input signal detector and the output end of the output signal detector, and are used to compare and analyze the input detection signal and the output detection signal; the first operation circuit 107 is used to perform operations according to the comparison and analysis results of the first comparator 106, and input the operation results to the first digital-to-analog converter 108, and the first digital-to-analog converter 108 is connected to the first heater 103, and is used to adjust the temperature of the first heater 103 according to the operation results.

Referring to FIG. 2 , the temperature control debugging method of the micro-ring wavelength division multiplexing optical transmitter includes the following steps:

A1. Design the radius of the first ring waveguide 102 of each micro-ring modulator so that the resonance peak of the first ring waveguide 102 is shifted to a wavelength band smaller than the wavelength of the corresponding working light beam.

A2. Perform standardized optical modulation amplitude analysis on each micro-ring modulator by adjusting the first heater 103 on each micro-ring modulator.

As shown in FIG3 and FIG4, the transmission responses under two different bias voltages (0V/3V) are obtained by the detector, and the two figures show the OMA under different wavelengths; in order to make the resonant cavity reach the maximum OMA, the average transmission response loss of λ _max corresponding to the maximum OMA at this time is recorded, and this value is used as a reference for temperature control feedback adjustment; the average transmission loss at the drop end corresponding to λ _max is a, and it can be obtained that α＝P _out /P _in ＝10 ^0.1a in the ideal state. The output photodetector 104 will couple out the optical power of k in the waveguide, and at this time P _n ＝(1-α)(1-k)P _in . Under ideal conditions, R _n ＝R ₀ *P _in /P _n , taking the situation shown in FIG3 as an example, at this time a＝-6dB, it can be obtained that α＝0.25, assuming R ₀ is 10Ω, k is 0.05, at this time R ₁ ＝R ₀ *P _in /P ₁ ＝14Ω.

When the maximum value point of the standardized optical modulation amplitude curve of the i-th micro-ring modulator changes, the current signal ratio is _Ii / _I0i , _R0 is the resistance value of the fixed resistor set as needed, _I0i is the current value measured by the input photodetector _105PD0i , and _Ii is the current value measured by the output photodetector _104PDi ; _V0i = _I0i · _R0 , under the condition of _V0i = _V0 , according to _Ii / _I0i = _R0 / _R1 , the resistance values of the adjustable resistors are calculated in sequence, i = 1...n; that is, by adjusting the temperature of the first ring waveguide 102, the effective refractive index _Neff of the first ring waveguide 102 is changed, so that the wavelength of light passing through the first ring waveguide 102 meets the resonance condition of the first ring waveguide 102, and the temperature of each first ring waveguide 102 is adjusted in sequence, so that each light wavelength can meet the resonance condition of the corresponding first ring waveguide 102; the current magnitude _I1 of the corresponding output photodetector 104 of each first ring waveguide 102 is read at this time , I ₂ ...I _n , to determine the resistance values of each resistor R ₁ ...R _n in the system under the corresponding input light wavelength state.

A3, start the wavelength division multiplexing optical transmitter, and start the temperature control adjustment system, the input signal detector and the output signal detector at the same time; start adjusting the transmission state of the working light beam in the micro-ring modulator from the first micro-ring modulator; according to V′ ₀₁ =I′ ₀₁ ·R ₀ , V′ ₁ =I′ ₁ ·R ₁ , wherein V′ ₁ is the output voltage of the ring waveguide of the first micro-ring modulator after the optical signal is converted into an electrical signal, and V′ ₀₁ is the input voltage of the first micro-ring modulator after the optical signal is converted into an electrical signal; based on step A1, at this time V′ ₁ ＞V′ ₀₁ , the comparator outputs the signal to the operation circuit, the operation circuit operates on the signal and then outputs it to the digital-to-analog converter, the digital-to-analog converter adjusts the current loaded on the heater according to the operation result to heat the micro-ring modulator until V′ ₁ ≤V′ ₀₁ , and maintains the temperature to make the resonance peak in an ideal position to ensure that the light beam to be transmitted enters the linear waveguide for transmission.

For the i-th micro-ring modulator, the transmission state of the working light beam in the micro-ring modulator is judged according to V′ _0i =I′ _0i ·R ₀ , V′ _i =I′ _i ·R _i , wherein V′ _i is the output voltage of the first ring waveguide 102 of the i-th micro-ring modulator after the optical signal is converted into an electrical signal, and V′ _0i is the input voltage of the i-th micro-ring modulator after the optical signal is converted into an electrical signal.

Based on step A1, at this time V′ _i ＞V′ _0i , the first comparator 106 outputs the comparison signal of V′ _0i and V′ _i to the first operation circuit 107, and the first operation circuit 107 operates on the signal and outputs it to the first digital-to-analog converter 108. The first digital-to-analog converter 108 adjusts the current loaded on the first heater 103 according to the operation result to heat the micro-ring modulator until V′ _i ≤V′ _0i , and maintains the temperature to make the resonance peak in an ideal position, so as to ensure that the light beam to be transmitted enters the first linear waveguide 101 for transmission.

Then the next micro-ring modulator is adjusted until the adjustment of n micro-ring modulators is completed, so that the light beams to be transmitted among the working light beams of the n micro-ring modulators are transmitted in the first linear waveguide 101 of the micro-ring modulator.

Example 2

Referring to Figure 5, this embodiment provides a micro-ring wavelength division multiplexing optical receiver, which includes n micro-ring filters and n second temperature control adjustment units respectively connected to the n micro-ring filters, and the n second temperature control adjustment units are correspondingly connected to n adjustable reference voltages; n is the total number of wavelengths received in the wavelength division multiplexing optical receiver, and n is an integer greater than or equal to 1.

The microring filter comprises a second straight waveguide 201 and a second annular waveguide 202 coupled to the second straight waveguide 201; n second straight waveguides 201 are connected in sequence; the relationship between the radius of the second annular waveguide 202 of the microring filter and the corresponding wavelength is: mλ _m =2πr ₂ n _2eff , wherein m is the resonance order, λ _m is the resonance wavelength of the mth order, r ₂ is the radius of the second annular waveguide 202, and n _2eff is the effective refractive index of the second annular waveguide 202; the waveguide material of the microring filter is silicon, and the waveguide thickness of the microring filter is 200nm-1000nm, which can realize wavelength division multiplexing of 1260nm-1360nm or 1530nm-1625nm band.

The second temperature control and adjustment unit includes a second heater 203 integrated on the second annular waveguide 202, an output signal detection component and a second temperature control circuit, wherein the second heater 203 is a titanium nitride heater or a lightly doped silicon resistance heater.

The output signal detection component includes a photodetector 204, a transimpedance amplifier 205 and a low-pass filter 206 connected in sequence; the photodetector 204 is a germanium silicon photodiode and is connected to the second ring waveguide 202, and is used to detect the optical signal in the second ring waveguide 202; the resistor in the transimpedance amplifier 205 is an adjustable resistor; the output signal detection component is used to generate an output voltage and transmit it to the second temperature control circuit.

The output end of the transimpedance amplifier 205 is also connected to the receiving device 210 for receiving the optical signals of the corresponding wavelengths filtered out by each microring filter.

The second temperature control circuit includes a second comparator 207, a second operation circuit 208 and a second digital-to-analog converter 209 connected in sequence; the second comparator 207 is used to receive a reference voltage and an output voltage and perform comparative analysis; the second operation circuit 208 is used to perform calculations based on the comparative analysis results of the second comparator 207, and input the calculation results to the second digital-to-analog converter 209. The second digital-to-analog converter 209 is connected to the second heater 203 and is used to adjust the temperature of the second heater 203 based on the calculation results.

Referring to FIG. 6 , the temperature control debugging method of the micro-ring wavelength division multiplexing optical receiver includes the following steps:

B1. Obtain the initial reference voltage of each second comparator 207; the calculation formula of the initial reference voltage V′ _j is as follows:

V′ _j = (P _j -P _{j loss} ) · R _j · G _j

Wherein, _Pj is the original optical power of the corresponding optical wavelength in the jth microring filter, Pj _loss is the maximum optical power loss value of the corresponding optical wavelength in the jth microring filter, _Rj is the response rate of the photodetector _204PDj connected to the jth microring filter, _Gj is the gain of the transimpedance amplifier 205 connected to the photodetector _204PDj , and j=1…n.

B2. Adjust the second heaters 203 integrated on each second ring waveguide 202 so that the resonant wavelength of the microring filter is smaller than the input optical signal of the corresponding wavelength; at the same time, due to the change of the effective refractive index caused by the temperature adjustment, the n wavelengths enter the n second ring waveguides 202 in sequence from small to large or from large to small.

B3, start the micro-ring filter and the second temperature control adjustment unit, and adjust the filtering effect of the micro-ring filter starting from the first micro-ring filter;

The filtering effect of the j-th micro-ring filter is adjusted, and the optical signal in the j-th micro-ring filter forms an output voltage V _j after being processed by the output signal detection component. The second comparator 207 receives the output voltage V _j and the initial reference voltage V ′ _j and compares them. As shown in the schematic diagram of the structure of the wavelength division multiplexing optical receiver in FIG5 , the light of the light signals of different wavelengths with n wavelengths of λ ₁ , λ ₂ ...λ _n is input from the left side of the waveguide. At this time, the resonant wavelength of the micro-ring filter is not on λ ₀ , λ ₁ , λ ₂ ...λ _n , and the resonant wavelength is smaller than the input light wavelength. The Drop end response of each ring is very low. For the j-th micro-ring filter, at this time, the initial reference voltage V ′ _j set according to the input optical power is greater than V _j , and the second heater 203 starts to work so that the Drop end response rises, and V _j becomes larger (in order to prevent the initial reference voltage set from being too large, V _j cannot be reached, and V ′ _j is generally smaller in the initial value), and finally V _j will be equal to or greater than V ′ _j . After V _n is equal to or greater than V′ _j , V′ _j is increased by a certain amplitude. At this time, the reference voltage V′ _j is greater than V _j again. The second heater 203 continues to work so that the Drop end response rises, and V _j continues to increase. In this process cycle, as V′ _j rises, V _j will gradually be unable to be greater than V′ _{j ,} indicating that V′ _j exceeds the maximum value of V _j at this time. Assuming that V _j cannot be greater than V′ _j after x times of adjustment, the temperature range of the xth and x-1th adjustments is controlled by the second heater 203, and the micro-ring filter is locked in the current state to complete the feedback adjustment. In this adjustment method, the adjustment amplitude of the reference voltage should be small, and the adjustment amplitude meets the voltage adjustment accuracy requirements. However, the smaller the adjustment amplitude of the reference voltage, the longer the adjustment process. This small-amplitude adjustment is suitable for use when the span between the initial reference voltage and the reference voltage after x times of adjustment is small.

This embodiment uses the reference voltage median method for comparison, specifically:

B3.1. Based on the method for obtaining the initial reference voltage V′ _j in step B1, V _j ＜V′ _j , then: step a. Regulate the second heater 203 through the second temperature control circuit to increase V _j to V _j1 and V _j1 is greater than V′ _j ; step b. Regulate the reference voltage to 2V′ _j so that V _j1 is less than 2V′ _j ; repeat step a to increase V _j1 to V _j2 and V _j2 is greater than 2V′ _j , repeat step b, adjust the reference voltage to 3V′ _j , V _j2 is less than 3V′ _j ; until the second heater 203 cannot achieve V _jn ＞nV′ _j ; if the voltage adjustment accuracy meets the requirements, use the second heater 203 to maintain the temperature so that the resonance peak is in an ideal position to achieve the corresponding wavelength filtering in the jth microring filter, and execute B3.3; if the voltage adjustment accuracy does not meet the requirements, execute B3.2.

B3.2. Take the median voltage V _M1 of (n-1)V′ _j and nV′ _j , adjust the second heater 203, and determine the relationship between the output voltage and the median voltage V _M1 :

If the output voltage can be greater than the median voltage V _M1 , then the median voltage V _M1 and the median voltage V _M2 of nV′ _j are taken, and the second heater 203 is adjusted to determine the relationship between the output voltage and the median voltage V _M2 ;

If the output voltage cannot be greater than the median voltage V _M1 , then the median voltage V _M3 of (n-1)V′ _j and the median voltage V _M1 is taken, and the second heater 203 is adjusted to determine the relationship between the output voltage and the median voltage V _M3 ;

The median of the reference voltage is taken and judged in sequence until the output voltage cannot be greater than the median voltage and the adjustment accuracy of the median voltage meets the requirements, and the second heater 203 is used to maintain the temperature to make the resonance peak in the ideal position to achieve the corresponding wavelength filtering in the jth microring filter.

B3.3. Then adjust the next micro-ring filter until the adjustment of n micro-ring filters is completed, thereby achieving the corresponding wavelength filtering in the n micro-ring filters.

Example 3

This embodiment provides a wavelength division multiplexer, which includes the above-mentioned wavelength division multiplexing optical transmitter based on micro-ring and the above-mentioned wavelength division multiplexing optical receiver based on micro-ring.

Claims (5)

1. A temperature control debugging method of a micro-ring wavelength division multiplexing optical transmitter adopts the micro-ring wavelength division multiplexing optical transmitter, wherein the micro-ring wavelength division multiplexing optical transmitter comprises a laser, n micro-ring modulators sequentially connected with the laser and n first temperature control adjusting units respectively connected with the n micro-ring modulators, n is an integer and n is more than or equal to 1; the emitted light of the laser comprises n wavelength working beams, the n working beams correspond to the n micro-ring modulators and the n first temperature control and regulation units respectively, and each wavelength working beam is split into a detection beam and a beam to be transmitted; the light beam to be transmitted enters a corresponding micro-ring modulator for transmission, the detection light beam enters a corresponding first temperature control and regulation unit as a contrast light signal, and the detection light beam accounts for 1% -10% of the working light beam;

the micro-ring modulator comprises a first linear waveguide (101) and a first annular waveguide (102) coupled with the first linear waveguide (101); the n first linear waveguides (101) are sequentially connected;

the first temperature control adjusting unit comprises a first heater (103), an input signal detector, an output signal detector and a first temperature control circuit which are integrally arranged on the first annular waveguide (102);

the input signal detector comprises an input photoelectric detector (105) and a fixed value resistor, and is used for detecting the detection light beam and generating an input detection signal;

the output signal detector comprises an output photoelectric detector (104) and an adjustable resistor, and is used for detecting the light beam in the first annular waveguide (102) and generating an output detection signal;

the first temperature control circuit comprises a first comparator (106), a first operation circuit (107) and a first digital-to-analog converter (108) which are connected in sequence; two input ends of the first comparator (106) are respectively connected with the output end of the input signal detector and the output end of the output signal detector and are used for carrying out comparison analysis on the input detection signal and the output detection signal; the first operation circuit (107) is used for performing operation according to the comparison analysis result of the first comparator (106), inputting the operation result to the first digital-to-analog converter (108), and the first digital-to-analog converter (108) is connected with the first heater (103) and is used for adjusting the temperature of the first heater (103) according to the operation result;

the relationship between the radius of the first annular waveguide (102) of the micro-ring modulator and the corresponding wavelength is as follows: mλ (m lambda) _m ＝2πr ₁ n _1eff Wherein m is the resonant order, lambda _m Is the resonance wavelength of the m-th order, r ₁ Is the radius of the first annular waveguide (102), n _1eff Is the effective refractive index of the first annular waveguide (102);

the waveguide material of the micro-ring modulator is silicon, the waveguide thickness of the micro-ring modulator is 200nm-1000nm, and wavelength division multiplexing of wave bands of 1260nm-1360nm or 1530nm-1625nm can be realized; the method is characterized by comprising the following steps of:

a1, setting the radius of a first annular waveguide (102) for designing each micro-ring modulator, so that the resonance peak of the first annular waveguide (102) shifts to a wave band smaller than the wavelength of a corresponding working beam;

a2, carrying out standardized light modulation amplitude analysis on each micro-ring modulator by adjusting a first heater (103) on each micro-ring modulator; the current signal ratio at the maximum point of the standardized light modulation amplitude curve change of the ith micro-ring modulator is I _i /I _0i ，R ₀ To be set according to the needResistance value of constant value resistor, I _0i For inputting the photo detector (105) PD _0i Measured current value, I _i For outputting the photo detector (104) PD _i A measured current value; v (V) _0i ＝I _0i ·R ₀ At V _0i ＝V _i Under the condition of according to I _i /I _0i ＝R ₀ /R _i Sequentially calculating the resistance value of the adjustable resistor; i= … n;

a3, starting the wavelength division multiplexing optical transmitter, and simultaneously starting the temperature control and adjustment system, the input signal detector and the output signal detector; starting to adjust the transmission state of the working beam in the micro-ring modulator from the first micro-ring modulator;

judging the transmission state of the working beam in the micro-ring modulator according to V 'for the ith micro-ring modulator' _0i ＝I′ _0i ·R ₀ ，V′ _i ＝I′ _i ·R _i Wherein V' _i Is the output voltage of the ith micro-ring modulator after the optical signal is converted into the electric signal in the first annular waveguide (102), V' _0i Comparing the input voltage of the optical signal converted into the electric signal for the ith micro-ring modulator;

based on step A1, at this time V' _i ＞V′ _0i The first comparator (106) will be V' _0i And V' _i The comparison signal is output to a first operation circuit (107), the first operation circuit (107) operates the signal and outputs the signal to a first digital-to-analog converter (108), and the first digital-to-analog converter (108) adjusts the current loaded on the first heater (103) according to the operation result to heat the micro-ring modulator until V '' _i ≤V′ _0i Maintaining a temperature for enabling the resonance peak to be at an ideal position, and ensuring that a light beam to be transmitted enters a first linear waveguide (101) for transmission;

and then adjusting the next micro-ring modulator until the adjustment of the n micro-ring modulators is completed, so that the light beams to be transmitted in the working light beams of the n micro-ring modulators are transmitted in the first linear waveguide (101) of the micro-ring modulators.

2. The temperature control debugging method of the micro-ring wavelength division multiplexing optical transmitter according to claim 1, wherein the temperature control debugging method comprises the following steps:

the input photoelectric detector (105) and the output photoelectric detector (104) are germanium-silicon photodiodes;

the first heater (103) is a titanium nitride heater or a lightly doped silicon resistive heater.

3. The temperature control debugging method of the micro-ring wavelength division multiplexing optical receiver adopts the micro-ring wavelength division multiplexing optical receiver, wherein the micro-ring wavelength division multiplexing optical receiver comprises n micro-ring filters and n second temperature control adjusting units which are respectively connected with the n micro-ring filters, and the n second temperature control adjusting units are correspondingly connected with n adjustable reference voltages; n is the total number of wavelengths received in the wavelength division multiplexing optical receiver, and n is an integer greater than or equal to 1;

the micro-ring filter comprises a second linear waveguide (201) and a second annular waveguide (202) which is coupled with the second linear waveguide (201); n second linear waveguides (201) are sequentially connected;

the second temperature control adjusting unit comprises a second heater (203), an output signal detecting component and a second temperature control circuit which are integrally arranged on the second annular waveguide (202);

the output signal detection assembly comprises a photoelectric detector (204), a transimpedance amplifier (205) and a low-pass filter (206) which are connected in sequence; the photoelectric detector (204) is connected with the second annular waveguide (202) and is used for detecting optical signals in the second annular waveguide (202); the resistance in the transimpedance amplifier (205) is an adjustable resistance; the output signal detection component is used for generating output voltage and transmitting the output voltage to the second temperature control circuit;

the second temperature control circuit comprises a second comparator (207), a second operation circuit (208) and a second digital-to-analog converter (209) which are connected in sequence; the second comparator (207) is used for receiving a reference voltage and an output voltage and performing comparison analysis; the second operation circuit (208) is used for performing operation according to the comparison analysis result of the second comparator (207), inputting the operation result to the second digital-to-analog converter (209), and connecting the second digital-to-analog converter (209) with the second heater (203) for adjusting the temperature of the second heater (203) according to the operation result;

the relationship between the radius of the second annular waveguide (202) of the micro-ring filter and the corresponding wavelength is as follows: mλ (m lambda) _m ＝2πr ₂ n _2eff Wherein m is the resonant order, lambda _m Is the resonance wavelength of the m-th order, r ₂ Is the radius of the second annular waveguide (202), n _2eff Is the effective refractive index of the second annular waveguide (202);

the waveguide material of the micro-ring filter is silicon, the waveguide thickness of the micro-ring filter is 200nm-1000nm, and wavelength division multiplexing of wave bands of 1260nm-1360nm or 1530nm-1625nm can be realized; the method is characterized by comprising the following steps of:

b1, acquiring initial reference voltages of the second comparators (207);

b2, adjusting the second heater (203) integrated on each second annular waveguide (202) to enable the resonance wavelength of the micro-annular filter to be smaller than the input optical signal with the corresponding wavelength, and enabling n wavelengths to sequentially enter the n second annular waveguides (202) from small to large or from large to small;

b3, starting the micro-ring filter and the second temperature control adjusting unit, and adjusting the filtering effect of the micro-ring filter from the 1 st micro-ring filter;

b3.1, adjusting the filtering effect of the jth micro-ring filter, wherein the optical signal in the jth micro-ring filter is processed by the output signal detection component to form an output voltage V _j The second comparator (207) receives the output voltage V _j And an initial reference voltage V' _j And comparing; j= … n;

V _j ＜V′ _j then: step a, regulating a second heater (203) through a second temperature control circuit to enable V _j Raised to V _j1 And V is _j1 Greater than V' _j The method comprises the steps of carrying out a first treatment on the surface of the Step b, regulating the reference voltage to be 2V' _j Make V _j1 Less than 2V' _j The method comprises the steps of carrying out a first treatment on the surface of the Repeating step a to make V _j1 Raised to V _j2 And V is _j2 Greater than 2V' _j Repeating the step b, and adjusting the reference voltage to 3V' _j Make V _j2 Less than 3V' _j The method comprises the steps of carrying out a first treatment on the surface of the Repeating step a and step b until the second heater (203) is adjusted to not achieve V _jn ＞nV′ _j The method comprises the steps of carrying out a first treatment on the surface of the If the voltage regulation precision meets the requirement, maintaining the temperature by adopting a second heater (203) for enabling a resonance peak to be in an ideal position, realizing the corresponding wavelength filtering in the j-th micro-ring filter, and executing B3.3; if the voltage regulation precision does not meet the requirement, executing B3.2;

b3.2, taking (n-1) V' _j With nV' _j Median voltage V of (2) _M1 Adjusting the second heater (203) to determine the output voltage and the median voltage V _M1 Is the relation of:

if the output voltage is greater than the median voltage V _M1 Then take the median voltage V _M1 With nV' _j Median voltage V of (2) _M2 Adjusting the second heater (203) to determine the output voltage and the median voltage V _M2 Is a relationship of (2);

if the output voltage cannot be greater than the median voltage V _M1 Then (n-1) V 'is taken' _j And median voltage V _M1 Median voltage V of (2) _M3 Adjusting the second heater (203) to determine the output voltage and the median voltage V _M3 Is a relationship of (2);

sequentially judging the median value of the reference voltage until the output voltage cannot be larger than the median voltage and the adjustment accuracy of the voltage meets the requirement, and maintaining the temperature by using a second heater (203) for enabling the resonance peak to be in an ideal position so as to realize the corresponding wavelength filtering in the j-th micro-ring filter;

and B3.3, adjusting the next micro-ring filter until the adjustment of the n micro-ring filters is completed, and realizing the corresponding wavelength filtering in the n micro-ring filters.

4. A temperature control debugging method of a micro-ring wavelength division multiplexing optical receiver according to claim 3, wherein:

the photodetector (204) is a germanium-silicon photodiode, and the second heater (203) is a titanium nitride heater or a lightly doped silicon resistance heater.

5. The temperature control debugging method of the micro-ring wavelength division multiplexing optical receiver according to claim 4, wherein the temperature control debugging method comprises the following steps:

in step B1Initial reference voltage V' _j The calculation formula of (c) is as follows,

V′ _j ＝(P _j -P _{j loss (j)} )·R _j ·G _j

Wherein P is _j The original optical power corresponding to the optical wavelength in the jth micro-ring filter, P _{j loss (j)} The maximum loss value of the optical power of the corresponding optical wavelength in the jth micro-ring filter is R _j Photodetector (204) PD connected for the jth micro-ring filter _j Response rate of G _j Is a photodetector (204) PD _j Gain of the connected transimpedance amplifier.