Disclosure of Invention
Aiming at the defects and improvement requirements of the prior art, the invention provides a multi-stage assembly line time division multiplexing feedback control method and a multi-stage assembly line time division multiplexing feedback control system, and aims to solve the technical problems that the utilization rate of functional circuit modules of a control circuit in the traditional time division multiplexing control method is low, and the number of controllable photonic devices is limited.
To achieve the above object, according to an aspect of the present invention, there is provided a multistage pipeline time division multiplexing feedback control method, including:
dividing the control circuit unit into n functional circuit modules working sequentially, wherein the response time of each functional circuit module is m1·TC、m2·TC、......、mn·TCWherein, TCN is an integer greater than 2, and m is the response time of the control circuit unit1+m2+......+mn=1,m1≤m2≤…≤mn;
Under the control of the time sequence generating and controlling module, the multiplexer selects the signal of the ith channel and transmits the signal to the 1 st functional circuit module, wherein i is an integer greater than 0;
through m1·TCThe 1 st functional circuit module transmits the signal of the ith channel to the 2 nd functional circuit module; meanwhile, the multiplexer selects signals of an (i +1) th channel to transmit to the 1 st functional circuit module;
through m1·TC+m2·TCThe 2 nd functional circuit module transmits the signal of the ith channel to the 3 rd functional circuit module; meanwhile, the 1 st functional circuit module transmits signals of the (i +1) th channel to the 2 nd functional circuit module; meanwhile, the multiplexer selects signals of an i +2 th channel and transmits the signals to the 1 st functional circuit module;
until T is passedCThe nth functional circuit module transmits the signal of the ith channel to the demultiplexer, the demultiplexer transmits the signal of the ith channel to the ith driver, and the ith driver controls the heat modulator of the ith integrated photonic device, so that the working state of the ith integrated photonic device is changed.
Further, n is 3, and m1=m2=m3=1/3;
The control circuit unit includes: the device comprises a front-end processing circuit, an algorithm processing circuit and an output stage circuit;
under the control of the time sequence generating and controlling module, the multiplexer selects the signal of the ith channel and transmits the signal to the front-end processing circuit, the front-end processing circuit is used for judging the change trend of the signal of the ith channel, wherein i is an integer greater than 0;
pass through 1/3TCThe front-end processing circuit transmits the signal of the ith channel to the algorithm processing circuit, and the algorithm processing circuit is used for determining the change trend of the current output signal of the ith channel according to the slope information of the current input signal of the ith channel and the change trend of the output signal at the last moment; meanwhile, the multiplexer selects signals of an (i +1) th channel and transmits the signals to the front-end processing circuit;
pass through 2/3TCThe arithmetic processing circuit transmits the signal of the ith channel to the output stage circuit, and the output stage circuit is used for generating an analog signal to be output; meanwhile, the front-end processing circuit transmits signals of the (i +1) th channel to the algorithm processing circuit; meanwhile, the multiplexer selects signals of an i +2 th channel and transmits the signals to the front-end processing circuit;
through TCThe output stage circuit transmits the signal of the ith channel to the demultiplexer, the demultiplexer transmits the signal of the ith channel to the ith driver, and the ith driver controls the heat regulator of the ith integrated photonic device, so that the working state of the ith integrated photonic device is changed; meanwhile, the algorithm processing circuit transmits signals of the (i +1) th channel to the output stage circuit; meanwhile, the front-end processing circuit transmits signals of the (i + 2) th channel to the algorithm processing circuit; and simultaneously, the multiplexer selects the signal of the (i + 3) th channel and transmits the signal to the front-end processing circuit.
The invention also provides a multistage assembly line time division multiplexing feedback control system, which uses the multistage assembly line time division multiplexing feedback control method and comprises the following steps: the system comprises k refractive index information acquisition units, a multiplexer, a control circuit unit, a time sequence generation and control module, a demultiplexer, k drives, k heat regulators and k integrated photonic devices; the multiplexer comprises k input ends, 1 output end and 1 control end, the demultiplexer comprises k output ends, 1 input end and 1 control end, and k is an integer larger than 1;
the k input ends of the multiplexer are respectively connected with the k refractive index information acquisition units, the output end of the multiplexer is connected with one end of the control circuit unit, the other end of the control circuit unit is connected with the input end of the demultiplexer, the k output ends of the demultiplexer are respectively connected with the k drivers, the k drivers are respectively connected with the k heat conditioners, and the k heat conditioners are used for respectively controlling the temperature of the k integrated photonic devices;
the time sequence generation and control module is respectively connected with the control end of the multiplexer, the control circuit unit and the control end of the demultiplexer and is used for controlling the conduction of each control loop in a multi-stage pipeline time division multiplexing mode, wherein the ith control loop is a loop formed by an ith integrated photonic device, an ith refractive index information acquisition unit, an ith input end of the multiplexer, the control circuit unit, an ith output end of the demultiplexer, an ith driver and an ith heat modulator, i is more than or equal to 1 and less than or equal to k, and i is an integer.
Further, the integrated photonic device is an integrated photonic device whose operating point needs to be dynamically adjusted by a thermal regulator, and the implementation manner is one of the following:
a micro-ring resonator, a micro-ring modulator, a Mach-Zehnder interferometer, a Mach-Zehnder modulator, and a photodiode;
the realization mode of the heat regulator in the integrated photonic device is one of the following modes:
metal or alloy resistance, doping resistance, and an off-chip temperature regulation platform.
Further, the refractive index information obtaining unit is an on-chip or off-chip photonic device capable of obtaining an effective refractive index or a working state of the integrated photonic device, and the implementation mode is one of the following:
photodiodes, contactless integrated photonic probes, doped waveguides based on the photoconductive effect.
Further, the multiplexer and the demultiplexer are circuits having a channel selection function.
Further, the driving is a circuit capable of driving the heat regulator to work, and the implementation mode is one of the following modes:
the device comprises a power tube array, a low dropout linear regulator and a DC/DC circuit.
Generally, by the above technical solution conceived by the present invention, the following beneficial effects can be obtained:
the invention is based on that the integral control circuit is subjected to first-stage time division multiplexing to control a plurality of photonic devices; in the control circuit, different functional circuit modules are subjected to second-level time division multiplexing, and the number of controllable photonic devices is multiple times that of the traditional time division multiplexing method on the premise of not obviously increasing the area of the control circuit, so that the utilization rate of the functional circuit modules of the control circuit is improved, the number of controllable photonic devices is increased, and the control circuit is particularly suitable for large-scale integrated photonic systems.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
The invention provides a time division multiplexing feedback control method for a multistage assembly line, which carries out time division multiplexing again on different functional circuit modules in a control circuit on the basis that an integral control circuit carries out time division multiplexing to control a plurality of photonic devices, thereby avoiding the functional circuit from being in an idle state and greatly improving the number of the controlled photonic devices. The timing principle of the control method of the present invention is illustrated as shown in fig. 4. Assuming that the thermo-optic modulation response time of the photonic device is TPTThe response time of the feedback control circuit is TC,TPT=3TCWherein S, C and O are respectively 1/3T of the working time of the sampling circuit in the control circuit, the working time of the arithmetic processing circuit and the working time of the output stage circuitC. Through two-stage time division multiplexing, three functional circuit modules all work in an idle state. At this time, the number of photonic devices which can be controlled by the method is 12, and under the same condition, the number of photonic devices which can be controlled by the pipeline time division multiplexing control method is only 4.
Assuming that the thermo-optic modulation response time of the photonic device is TPTThe response time of the feedback control circuit is TC,,TPT=N×TCThe control circuit can be divided into n functional circuit modules working sequentially, and the response time of each functional circuit module is m1·TC、m2·TC、......、mn·TCWherein, TCN is an integer greater than 2, and m is the response time of the control circuit unit1+m2+......+mn=1,m1≤m2≤…≤mn(ii) a On the basis of not reducing the regulation speed of each photonic device, namely, the single response, waiting and control time of each photonic device is TPT+TCThe number of the photonic devices which can be controlled by the method is (N +1)/mn. In an optimal case, the control circuit may be divided into n functional circuit blocks working sequentially, and the response time of each functional circuit block is 1/n × TC. At the moment, on the basis of not reducing the regulation speed of each photonic device, the number of the photonic devices which can be controlled by the method is N x (N + 1); under the same condition, the number of the photonic devices which can be controlled by the pipeline time division multiplexing control method is number N +1, and the direct time division multiplexing control method sacrifices the regulation speed of each photonic device. It can be seen that the number of photonic devices that can be controlled by the control method of the present invention is n times that of the conventional control method under almost the same conditions.
Another aspect of the present invention provides a multistage pipeline time division multiplexing feedback control system, a block diagram of which is shown in fig. 5, including: the system comprises k refractive index information acquisition units, a multiplexer, a control circuit unit, a time sequence generation and control module, a demultiplexer, k drives, k heat regulators and k integrated photonic devices; the multiplexer comprises k input ends, 1 output end and 1 control end, the demultiplexer comprises k output ends, 1 input end and 1 control end, and k is an integer larger than 1;
the k input ends of the multiplexer are respectively connected with the k refractive index information acquisition units, the output end of the multiplexer is connected with one end of the control circuit unit, the other end of the control circuit unit is connected with the input end of the demultiplexer, the k output ends of the demultiplexer are respectively connected with the k drivers, the k drivers are respectively connected with the k heat conditioners, and the k heat conditioners are used for respectively controlling the temperature of the k integrated photonic devices;
the time sequence generation and control module is respectively connected with the control end of the multiplexer, the control circuit unit and the control end of the demultiplexer and is used for controlling the conduction of each control loop in a multi-stage pipeline time division multiplexing mode, wherein the ith control loop is a loop formed by an ith integrated photonic device, an ith refractive index information acquisition unit, an ith input end of the multiplexer, the control circuit unit, an ith output end of the demultiplexer, an ith driver and an ith heat modulator, i is more than or equal to 1 and less than or equal to k, and i is an integer.
The present invention is further illustrated in detail below using three specific examples.
Example one
In switch array applications, the switching state of each switching element is controlled using a multi-stage pipelined time-division multiplexed feedback control method, and each switching element is not limited to one thermal modulator. FIG. 6 is a schematic diagram of the present embodiment, the 4 × 4 switch array being composed of 2 × 2 Mach-Zehnder-interferometer-based switch elements; a trans-impedance amplifier, a sample hold circuit and a comparator are used as a front-end processing circuit to obtain slope information; an algorithm processing circuit is adopted and a climbing algorithm is utilized to determine an output trend; converting the output trend of the algorithm processing circuit into analog voltage by adopting an analog-to-digital converter; a thermal regulator which adopts a power tube to drive each switch; a photodiode is employed as the refractive index information acquisition unit. The method comprises the following specific steps:
step 1, after a part of light at the output end of each Mach-Zehnder interferometer switch element is coupled out, converting optical power into photocurrent through a photodiode;
step 2, the time sequence generation and control module firstly controls the multiplexer to select the photocurrent I of the ith switchMiConverting the voltage signals into appropriate voltage signals through a trans-impedance amplifier, and obtaining the variation trend information of the ith channel voltage signal after the common processing of a sample hold circuit and a comparator;
step 3, via 1/3TCThe time sequence generation and control module controls the algorithm processing circuit to work, compares the current input signal change trend information of the ith channel with the change trend information of the last output signal, and judges the current output change trend of the ith channel according to the comparison result;
step 4, generating time sequence at the same time of step 3And the control module controls the multiplexer to select the photocurrent I of the (I +1) th switchMi+1Converting the voltage signals into appropriate voltage signals through a trans-impedance amplifier, and obtaining the variation trend information of the voltage signals of the (i +1) th channel after the common processing of a sample-and-hold circuit and a comparator;
step 5, via 2/3TCThe time sequence generation and control module controls the analog-to-digital converter to work and converts the current output change trend signal of the ith channel into an analog voltage signal VHi;
And 6, simultaneously with the step 5, controlling the multiplexer to select the photocurrent I of the (I + 2) th switch by the time sequence generating and controlling moduleMi+2Converting the voltage signals into appropriate voltage signals through a trans-impedance amplifier, and obtaining the variation trend information of the voltage signals of the (i + 2) th channel after the common processing of a sample hold circuit and a comparator;
step 7, at the same time of step 5, the time sequence generation and control module controls the algorithm processing circuit to work, the current input signal change trend information of the (i +1) th channel is compared with the change trend information of the last output signal, and the current output change trend of the (i +1) th channel is judged according to the comparison result;
step 8, passing through TCThe time sequence generating and controlling module controls the demultiplexer to select the ith channel, and the analog voltage signal drives the thermal modulator of the ith switch element through the power tube so as to control the switch state of the switch element;
and 9, repeating the steps 1 to 8.
Example two
In the application of the high-order micro-ring filter, the resonance state of each micro-ring is controlled by a multi-stage assembly line time division multiplexing feedback control method, and the implementation mode of the micro-ring array is not limited. FIG. 7 is a diagram illustrating the embodiment, in which the high-order micro-ring filter is composed of a fourth-order micro-ring; a trans-impedance amplifier, a sampling holding circuit and a comparator are used as a front-end processing circuit to obtain slope information; an algorithm processing circuit is adopted to determine an output trend by utilizing a climbing algorithm; converting the output trend of the algorithm processing circuit into analog voltage by adopting an analog-to-digital converter; a power tube is adopted to drive the heat regulator of each micro-ring; a photodiode is employed as the refractive index information acquisition unit. The method comprises the following specific steps:
step 1, after coupling out a part of light of each micro-ring, converting optical power into photocurrent through a photodiode;
step 2, the time sequence generation and control module firstly controls the multiplexer to select the photocurrent I of the ith micro-ringMiConverting the voltage signals into appropriate voltage signals through a trans-impedance amplifier, and obtaining the variation trend information of the ith channel voltage signal after the common processing of a sample hold circuit and a comparator;
step 3, via 1/3TCThe time sequence generation and control module controls the algorithm processing circuit to work, compares the current input signal change trend information of the ith channel with the change trend information of the last output signal, and judges the current output change trend of the ith channel according to the comparison result;
step 4, at the same time of step 3, the time sequence generation and control module controls the multiplexer to select the photocurrent I of the (I +1) th micro-ringMi+1Converting the voltage signals into appropriate voltage signals through a trans-impedance amplifier, and obtaining the variation trend information of the voltage signals of the (i +1) th channel after the common processing of a sample-and-hold circuit and a comparator;
step 5, via 2/3TCThe time sequence generation and control module controls the analog-to-digital converter to work and converts the current output change trend signal of the ith channel into an analog voltage signal VHi;
And 6, simultaneously with the step 5, controlling the multiplexer to select the photocurrent I of the (I + 2) th micro-ring by the time sequence generating and controlling moduleMi+2Converting the voltage signals into appropriate voltage signals through a trans-impedance amplifier, and obtaining the variation trend information of the voltage signals of the (i + 2) th channel after the common processing of a sample hold circuit and a comparator;
step 7, at the same time of step 5, the time sequence generation and control module controls the algorithm processing circuit to work, the current input signal change trend information of the (i +1) th channel is compared with the change trend information of the last output signal, and the current output change trend of the (i +1) th channel is judged according to the comparison result;
step 8, passing through TCThe time sequence generation and control module controls the demultiplexer to select the ith channel, and the analog voltage signal drives the heat regulator of the ith micro-ring through the power tube so as to control the resonance state of the micro-ring;
and 9, repeating the steps 1 to 8.
EXAMPLE III
In receiver applications where avalanche photodiodes are used to detect optical signals, the bias voltage of each avalanche photodiode is controlled using a multi-stage pipelined time division multiplexed feedback control method. Fig. 8 is a schematic diagram of this embodiment, in a dense wavelength division multiplexing receiver, a channel demultiplexer is used to demodulate a channel, and data information is restored through an avalanche photodiode and a receiving circuit. Obtaining a low pass filter output voltage V using a digital-to-analog converter as a front end processing circuitP(ii) a The algorithm processing circuit acquires the third derivative information of the input signal and determines the output trend by using a climbing algorithm; converting the output trend of the algorithm processing circuit into analog voltage by adopting an analog-to-digital converter; outputting a voltage V using a boost power stageBAs a bias for each avalanche diode. The method comprises the following specific steps:
step 1, adjusting the resonance wavelength of a certain micro-ring to demodulate a certain channel, converting the optical power into photocurrent through an avalanche photodiode, and reducing the photocurrent into data information through a receiving circuit;
step 2, the time sequence generation and control module controls the multiplexer to select the monitoring output voltage V of the ith avalanche photodiodePiConverting the signal into a digital signal through a digital-to-analog converter;
step 3, via 1/3TCThe time sequence generation and control module controls the algorithm processing circuit to work to obtain the third derivative information of the ith channel voltage signal change, the third derivative information currently input by the ith channel is compared with the change trend information of the last output signal, and the current output change trend of the ith channel is judged according to the comparison result;
step 4, simultaneously with the step 3The time sequence generation and control module controls the multiplexer to select the monitoring output voltage V of the (i +1) th avalanche photodiodePi+1Converting the voltage signal into a digital signal through an analog-to-digital converter, and obtaining the third derivative information of the change of the voltage signal of the (i +1) th channel;
step 5, via 2/3TCThe time sequence generation and control module controls the analog-to-digital converter to work and converts the current output change trend signal of the ith channel into an analog voltage signal;
step 6, at the same time of step 5, the time sequence generation and control module controls the multiplexer to select the monitoring output voltage V of the (i + 2) th avalanche photodiodePi+2Converting the signal into a digital signal through a digital-to-analog converter;
step 7, in the step 5, the time sequence generation and control module controls the operation of the algorithm processing circuit to obtain the third derivative information of the voltage signal change of the (i +1) th channel, compares the currently input third derivative information of the (i +1) th channel with the change trend information of the last output signal, and judges the current output change trend of the (i +1) th channel according to the comparison result;
step 8, passing through TCThe time sequence generation and control module controls the demultiplexer to select the ith channel, and the analog voltage signal outputs a voltage V through the boosting power stageBiAs the bias of the ith avalanche diode, thereby controlling the working state of the avalanche diode;
and 9, repeating the steps 1 to 8.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.