阅读说明：本技术 基于光延迟的光电混合模数转换方法与系统 (Photoelectric mixed analog-digital conversion method and system based on optical delay ) 是由 邱琪 张天航 范志强 苏君 史双瑾 王云祥 廖云 于 2019-10-25 设计创作，主要内容包括：发明涉及基于光延迟的光电混合模数转换方法与系统,其中方法包括：A.由时钟分配与控制模块产生1:n占空比的采样电脉冲信号,同时为n路并行电子模数转换模块提供电采样时钟信号；B.将光源输出的激光注入到电光调制器,由采样电脉冲信号调制得到采样光脉冲；C.将采样光脉冲放大后均分到n个延迟通道中延时形成n路并行时空分离的采样光脉冲；D.通过模拟信号对采样光脉冲调制,再对调制后的采样光脉冲展宽并转换成电信号；E.将得到的电信号模数变换完成量化,得到n路并行输出的数据信号；F.将所述n路并行的数据信号融合后输出。本发明有效降低了光电模数转换成本,并且还明显减小了采样光脉冲的抖动。(The invention relates to a photoelectric mixed analog-to-digital conversion method and a system based on optical delay, wherein the method comprises the following steps: A. a clock distribution and control module generates a sampling electric pulse signal with a 1: n duty ratio and provides an electric sampling clock signal for the n paths of parallel electronic analog-digital conversion modules; B. injecting laser output by a light source into an electro-optic modulator, and modulating by a sampling electric pulse signal to obtain a sampling optical pulse; C. amplifying the sampling light pulse, and then uniformly distributing the amplified sampling light pulse into n delay channels for time delay to form n paths of parallel time-space separated sampling light pulses; D. modulating the sampling light pulse through an analog signal, widening the modulated sampling light pulse and converting the sampling light pulse into an electric signal; E. the obtained electric signal is subjected to analog-to-digital conversion to complete quantization, and n paths of data signals which are output in parallel are obtained; F. and fusing the n paths of parallel data signals and outputting the fused data signals. The invention effectively reduces the photoelectric analog-to-digital conversion cost and also obviously reduces the jitter of the sampling light pulse.)

1. The photoelectric mixed analog-to-digital conversion method based on optical delay is characterized by comprising the following steps:

A. a clock distribution and control module generates a sampling electric pulse signal with a 1: n duty ratio and provides an electric sampling clock signal for the n paths of parallel electronic analog-digital conversion modules;

B. injecting laser output by a light source into an electro-optic modulator, and modulating by the electro-optic modulator to obtain sampling optical pulses with corresponding duty ratios and pulse widths after a sampling electrical pulse amplification module amplifies the sampling electrical pulse signals;

C. amplifying the sampling light pulse, and then uniformly dividing the amplified sampling light pulse into n delay channels for time delay to form n paths of parallel time-space separated sampling light pulses;

D. modulating the n paths of parallel space-time separated sampling light pulses through an analog signal output by an analog signal amplification module to complete light sampling, widening the modulated sampling light pulses, and converting the widened sampling light pulses into n paths of electric signals;

E. performing analog-to-digital conversion on the obtained n paths of electric signals to complete quantization to obtain n paths of data signals which are output in parallel;

F. and fusing the n paths of parallel data signals and outputting the fused data signals.

2. The optical delay-based photoelectric hybrid analog-to-digital conversion method according to claim 1, characterized in that: in the step A, the clock distribution and control module generates an electrical sampling clock signal with the frequency of f, and the repetition frequency of the sampling electrical pulse signal and the frequency of the electrical sampling clock signal of each circuit in the n-circuit parallel electronic analog-to-digital conversion module are both f/n.

3. The optical delay-based photoelectric hybrid analog-to-digital conversion method according to claim 1, characterized in that: in step a, the pulse width of the sampling electrical pulse signal is adjustable within one clock period.

4. The optical delay-based photoelectric hybrid analog-to-digital conversion method according to claim 1, characterized in that: in step B, the light source outputs laser with a broad spectrum.

5. The optical delay-based photoelectric hybrid analog-to-digital conversion method according to claim 2, wherein: in step C, the delay step is 1/f second.

6. An optical delay based opto-electronic hybrid analog-to-digital conversion system for use in the method of one of claims 1 to 5, characterized by: the sampling device is provided with a clock distribution and control module, wherein the clock distribution and control module outputs a sampling electric pulse signal generating a 1: n duty ratio to a sampling electric pulse amplification module and outputs a generated electric sampling clock signal to n paths of parallel electronic analog-to-digital conversion modules;

the electro-optical modulator receives laser output by the light source and a sampling electric pulse signal output by the sampling electric pulse amplification module at the same time, the sampling electric pulse amplification module amplifies the sampling electric pulse signal, the electro-optical modulator modulates the sampling electric pulse signal to obtain a sampling optical pulse with a corresponding duty ratio and a corresponding pulse width, the sampling optical pulse output by the electro-optical modulator is connected to n paths of optical fiber delay modules through an optical amplifier and an optical distributor, n paths of parallel time-space separated optical sampling pulses are output to n paths of electro-optical modulation modules, the n paths of electro-optical modulation modules modulate the n paths of parallel time-space separated optical sampling pulses according to an analog signal output by the received analog signal amplification module to complete optical sampling, and the n paths of modulated sampling optical pulses are broadened through the n paths of optical pulse amplification modules and then are converted into electric signals through the n paths of electro-optical detection and amplification modules, and the n paths of electronic analog-to-digital conversion modules receive the electric signals, and output n paths of data signals obtained after the electric signals are subjected to analog-to-digital conversion to the n paths of data fusion and processing modules in parallel for data fusion and processing and then output.

7. The optical delay-based opto-electronic hybrid analog-to-digital conversion system of claim 6, wherein: the electro-optical modulator is a broadband electro-optical modulator which generates high repetition frequency pulse signals.

8. The optical delay-based opto-electronic hybrid analog-to-digital conversion system of claim 6, wherein: the n-path optical pulse broadening module is provided with n sections of optical fibers, and the length of the optical fibers is suitable for the dispersion of optical signals, the spectral width of a light source and the broadening quantity of pulses.

9. The optical delay-based opto-electronic hybrid analog-to-digital conversion system of claim 6, wherein: the light source is a laser light source of a broad spectrum semiconductor.

10. The optical delay-based opto-electronic hybrid analog-to-digital conversion system of claim 6, wherein: in the n-path optical fiber delay module, n channels of an equal stepping optical fiber structure for delay are arranged.

Technical Field

The invention relates to a photoelectric mixed analog-to-digital conversion method and a system, in particular to a photoelectric mixed analog-to-digital conversion method and a system based on optical delay.

Background

In recent years, with the rapid development of microwave technology, the requirement for converting analog signals into digital signals is increasing, including core technical indexes such as high sampling rate, high bandwidth, and high quantization bit number.

At present, analog-digital conversion technology based on electronic technology has inherent defects in two indexes of sampling rate and bandwidth. In the 90 s of the last century, a great deal of manpower and material resources are invested in researching the analog-to-digital conversion technology based on the photoelectronic technology, and the analog-to-digital conversion technology based on the LiNbO is subjected to LiNbO₃The analog-to-digital conversion of the modulator array, the analog-to-digital conversion of the high-repetition-frequency mode-locking femtosecond pulse sampling based on the fiber laser and other technical routes, wherein key technologies such as ultrahigh-speed sampling light rate and high quantization digit are mainly researched. Years of domestic and foreign research show that the ultra-high sampling rate and ultra-wideband modulation technology based on the photon technology is the main reason that the analog-to-digital conversion technology favors the photon technology, and the electronic technology adopted by the quantization technology is the best method at present.

At present, most schemes adopted by people are acknowledged that a mode-locked fiber laser generates femtosecond optical pulse signals with high repetition frequency, a sampling optical pulse sequence with repetition frequency more than 10GHz is formed by multiplexing and combining the femtosecond optical pulse signals, and then an analog signal adopts broadband LiNbO₃The modulator modulates the high repetition frequency sampling optical pulse sequence to complete optical sampling of the analog signal. In order to facilitate the electric quantization, the modulated femtosecond pulse needs to be broadened, the pulse broadening is usually realized by adopting optical fiber dispersion, the broadened optical pulse sequence is grouped to form parallel sampling optical pulses, then the photoelectric conversion is sent to a parallel electronic analog-to-digital conversion chip to realize the quantization, and finally the parallel data is fused to complete the whole analog-to-digital conversion. The method is characterized in that firstly, sampling light pulse with high repetition frequency is obtained through a mode-locked fiber laser, and secondly, the light pulse is subjected to parallel processing and stretched and then subjected to photoelectric conversion. Its advantage is high effectThe sampling rate of the pulse technology has a large range, and the defects are that the femtosecond pulse fiber laser has high cost, and the pulse expands from femtosecond to nanosecond and has large signal damage.

Disclosure of Invention

The invention provides a photoelectric mixed analog-to-digital conversion method and a photoelectric mixed analog-to-digital conversion system based on optical delay, which can reduce photoelectric analog-to-digital conversion cost and reduce the jitter of sampling optical pulses.

The invention relates to a photoelectric mixed analog-to-digital conversion method based on optical delay, which comprises the following steps:

A. a clock distribution and control module generates a sampling electric pulse signal with a 1: n duty ratio and provides an electric sampling clock signal for the n paths of parallel electronic analog-digital conversion modules;

B. injecting laser output by a light source into an electro-optic modulator, and modulating by the electro-optic modulator to obtain sampling optical pulses with corresponding duty ratios and pulse widths after a sampling electrical pulse amplification module amplifies the sampling electrical pulse signals;

C. amplifying the sampling light pulse, and then uniformly dividing the amplified sampling light pulse into n delay channels for time delay to form n paths of parallel time-space separated sampling light pulses;

D. modulating the n paths of parallel space-time separated sampling light pulses through an analog signal output by an analog signal amplification module to complete light sampling, widening the modulated sampling light pulses, and converting the widened sampling light pulses into n paths of electric signals; the purpose of the broadening is to accommodate the lower quantization bandwidth and sampling rate of the electronic analog-to-digital conversion chip.

E. Performing analog-to-digital conversion on the obtained n paths of electric signals to complete quantization to obtain n paths of data signals which are output in parallel;

F. and fusing the n paths of parallel data signals and outputting the fused data signals.

The method combines the high sampling rate of the photon technology and the high number quantization digit of the electronic technology, obtains the optical pulse by the high-speed electro-optical modulation technology, and obtains the multi-channel sampling optical pulse with high repetition frequency by the multi-channel distribution of the optical signal and the multi-channel optical fiber delay. The purposes of broadband, high sampling rate, high effective digit and low cost are realized.

Further, in step a, the clock distribution and control module generates an electrical sampling clock signal with a frequency of f, and both the repetition frequency of the sampling electrical pulse signal and the frequency of the electrical sampling clock signal of each of the n parallel electronic analog-to-digital conversion modules are f/n.

Further, in step a, the pulse width of the sampling electrical pulse signal is adjustable within one clock period (1/f second).

Further, in step B, the light source outputs a broad spectrum laser.

Further, in step C, the delay is stepped by 1/f second.

The invention also provides a photoelectric mixed analog-digital conversion system based on optical delay for the method, which is provided with a clock distribution and control module, wherein the clock distribution and control module outputs a sampling electric pulse signal generating a 1: n duty ratio to a sampling electric pulse amplification module and outputs a generated electric sampling clock signal to an n-path parallel electronic analog-digital conversion module;

the electro-optical modulator receives laser output by the light source and a sampling electric pulse signal output by the sampling electric pulse amplification module at the same time, the sampling electric pulse amplification module amplifies the sampling electric pulse signal, the electro-optical modulator modulates the sampling electric pulse signal to obtain a sampling optical pulse with a corresponding duty ratio and a corresponding pulse width, the sampling optical pulse output by the electro-optical modulator is connected to n paths of optical fiber delay modules through an optical amplifier and an optical distributor, n paths of parallel time-space separated optical sampling pulses are output to n paths of electro-optical modulation modules, the n paths of electro-optical modulation modules modulate the n paths of parallel time-space separated optical sampling pulses according to an analog signal output by the received analog signal amplification module to complete optical sampling, and the n paths of modulated sampling optical pulses are broadened through the n paths of optical pulse amplification modules and then are converted into electric signals through the n paths of electro-optical detection and amplification modules, and the n paths of electronic analog-to-digital conversion modules receive the electric signals, and output n paths of data signals obtained after the electric signals are subjected to analog-to-digital conversion to the n paths of data fusion and processing modules in parallel for data fusion and processing and then output.

Further, the electro-optical modulator is a broadband electro-optical modulator which generates high repetition frequency pulse signals.

Furthermore, the n optical pulse stretching modules are provided with n sections of optical fibers, and the length of the optical fibers is suitable for the dispersion of optical signals, the spectral width of a light source and the stretching amount of pulses.

Furthermore, the light source is a laser light source of a broad spectrum semiconductor. The cost is effectively reduced by adopting a low-cost wide-spectrum semiconductor laser light source as a light source. The optical sampling is completed by modulating the multi-channel space-time separated sampling optical pulse through the analog signal, the multi-channel electronic analog-digital conversion chip is quantitatively sampled, and the technical problem that the bandwidth of the electronic analog-digital conversion chip is far smaller than the bandwidth of the optical sampling pulse is solved through the proper pulse broadening of the combination of the wide-spectrum light source and the optical fiber dispersion.

Furthermore, in the n-path optical fiber delay module, there are n channels of the equal-stepping optical fiber structure for delay.

The photoelectric mixed analog-to-digital conversion method and system based on optical delay effectively reduce photoelectric analog-to-digital conversion cost and also obviously reduce the jitter of sampling optical pulses.

The present invention will be described in further detail with reference to the following examples. This should not be understood as limiting the scope of the above-described subject matter of the present invention to the following examples. Various substitutions and alterations according to the general knowledge and conventional practice in the art are intended to be included within the scope of the present invention without departing from the technical spirit of the present invention as described above.

Drawings

Fig. 1 is a block diagram of an optical delay-based opto-electronic hybrid analog-to-digital conversion system according to the present invention.

Fig. 2 is a block diagram of an embodiment of fig. 1 where n is 8.

Fig. 3 is a flow chart of the photoelectric hybrid analog-to-digital conversion method based on optical delay according to the present invention.

Detailed Description

As shown in fig. 1 and fig. 2, the photoelectric hybrid analog-to-digital conversion system based on optical delay of the present invention includes:

the clock distribution and control module: an electrical sampling clock signal with the frequency of 20GHz is generated, a sampling electric pulse signal with the repetition frequency of 2.5GHz and the duty ratio of 1: n (in the embodiment, n is 8, and is expressed by 8 in the following) is generated, and meanwhile, the electrical sampling clock signal with the frequency of 2.5GHz is provided for each of the 8 electronic analog-digital conversion modules.

Sampling electric pulse amplification module: the receiving clock distribution and control module generates sampling electric pulse signals, amplifies the sampling electric pulse signals and outputs the amplified sampling electric pulse signals to the electro-optic modulator;

light source: a 1.55 μm waveband semiconductor laser light source with a spectral width of 10 nm;

an electro-optical modulator: LiNbO₃MZI type electro-optic modulator, its modulation bandwidth is greater than 40 GHz;

an optical amplifier: the saturated output power of the optical amplifier with the wave band of 1.55 mu m is more than 23 dBm;

a light distributor: 1:8 of a single-mode fiber power splitter;

8-path optical fiber delay module: the optical fiber comprises an equal-stepping optical fiber with 8 channels, wherein the delay stepping is 50ps (picosecond), 8 paths of parallel space-time separated sampling optical pulses are formed, and the optical sampling frequency is 20 GS/s;

the analog signal amplification module: after amplifying the analog signal, outputting a broadband analog signal to an 8-path electro-optical modulation module, and modulating the 8-path parallel time-space separated sampling optical pulses;

8-path electro-optical modulation module: completing the modulation of the sampling optical pulse formed by the parallel time delay of 8 paths by the broadband analog signal and the optical sampling;

8-path optical pulse widening module: broadening 8 modulated time-space separated sampling optical pulses, and adopting 8 channels of 1km G.652 standard single-mode optical fibers;

8-path optical detection and amplification module: converting the 8 paths of expanded sampling light pulses into electric signals and amplifying the electric signals;

8-path electronic analog-to-digital conversion module: performing analog-to-digital conversion on the electric signals obtained by the 8 paths of parallel photoelectric conversion and amplification to obtain data signals output in parallel, wherein an analog-to-digital conversion chip adopts a chip with a sampling rate of more than 2.5 GS/s;

8 data fusion and processing modules: and completing data fusion and processing of the parallel 8-path data signals.

As shown in fig. 2 and fig. 3, the photoelectric hybrid analog-to-digital conversion method based on optical delay of the present invention includes:

A. the clock distribution and control module generates an electric sampling clock signal with the frequency of 20GHz, generates a sampling electric pulse signal with the duty ratio of 1:8 and the repetition frequency of 2.5GHz, and provides an electric sampling clock signal with the frequency of 2.5GHz for the 8-path parallel electronic analog-digital conversion module;

B. LiNbO with modulation bandwidth larger than 40GHz₃The MZI type electro-optical modulator respectively receives semiconductor laser with a 1.55 mu m wave band of a spectrum width of 10nm output by a semiconductor laser light source and a 2.5GHz sampling electric pulse signal output by a clock distribution and control module after being amplified by a sampling electric pulse amplification module. Modulating semiconductor laser in an electro-optical modulator through a sampling electric pulse signal to obtain a sampling optical pulse signal with a 1:8 duty ratio and a repetition frequency of 2.5 GHz;

C. amplifying the sampling optical pulse signal with the repetition frequency of 2.5GHz by an optical amplifier, uniformly distributing the signal to the time delay of 8 channels in an 8-channel optical fiber time delay module through an optical distributor, wherein the time delay is stepped to 50ps, and the total time delay of the 8 channels is 400ps, so that 8-channel parallel time-space separated sampling optical pulses are formed, and the optical sampling frequency of the sampling optical pulse is 20 GS/s;

D. the analog signal outputs a broadband analog signal through an analog signal amplification module, 8 parallel space-time separated sampling light pulses are modulated in an 8-path electro-optical modulation module to complete optical sampling, then the modulated sampling light pulses are broadened in an 8-path optical pulse broadening module to obtain 8 paths of pulse broadened optical pulses, and then the 8 paths of optical pulses are converted into 8 paths of electric signals through an 8-path optical detection and amplification module;

the E.8 paths of electronic analog-digital conversion modules perform analog-digital conversion on the obtained 8 paths of electric signals to complete quantization, and 8 paths of data signals output in parallel are obtained, wherein the sampling frequency of an electronic analog-digital conversion chip in the 8 paths of electronic analog-digital conversion modules is 2.5 GS/s;

F. and finally, fusing the 8 paths of parallel data signals through an 8-path data fusion and processing module and then outputting the fused data signals.

The invention combines the high sampling rate of photon technology and the high number quantization digit of electronic technology, obtains optical pulse by high-speed electro-optical modulation technology, and obtains multi-channel sampling optical pulse with high repetition frequency by optical signal multi-channel distribution and multi-channel optical fiber delay. And the technical problem that the bandwidth of an electronic analog-digital conversion chip is far smaller than the bandwidth of an optical sampling pulse is solved by combining a wide-spectrum light source and optical fiber dispersion with proper pulse broadening.