Optical A/D converter based on asymmetric Mach-Zehnder modulator

Abstract

The invention is an optical A / D converter based on nonsymmetrical Mach-Zehnder modulator, belonging to the optical A / D converter technical field, characterized in that: it uses nonsymmetrical M-Z modulator to modulate electric signal to synchronous multi-wavelength input pulse, and selects proper length difference of two arms DeltaL and N wavelengths, able to make offset of DC biasing point between every two adjacent wavelengths at the outgoing end bepi / N, and the modulated multi-wavelength optical pulse is divided into N synchronous optical pulses by wavelength division multiplexer, and after determined by photoelectric detector and comparer, it can obtain N digital signal outputs. And the invention can implement very large modulated bandwidth and accurately control the offset of DC biasing point of two adjacent channels, implementing higher-digit A / D conversion and easy to implement.

Description

technical field [0001] The invention belongs to the technical field of information optoelectronics, in particular to an optical analog-to-digital converter. Background technique [0002] Analog-to-Digital Converter (Analog-to-Digital Conversion) is referred to as ADC, which is a device or device that converts an analog signal into a corresponding digital signal. [0003] Compared with analog systems, digital systems have obvious advantages in terms of stability, anti-interference ability, processing accuracy, and integration. Because of this, digital technology has achieved rapid development over the years, and it has penetrated into various technical fields. However, most physical signals in nature are analog. It is not difficult for people to think of converting the analog signal into a digital signal, and then use the digital system to process and process the converted signal, as the interface between the digital and analog systems. Converters are becoming more and more ...

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Problems solved by technology

[0013] It is not difficult to see that the quantization process of the first three types is actually carried out in the electrical domain, and light only plays an auxiliary role. They cannot fundamentally solve the bottleneck problem of electricity, and these solutions are relatively complicated to implement. easy to miniaturize

In contrast, in Taylor's analog-to-digital conversion scheme, quantization is performed in the optical domain, and it is easy to achieve integration. However, on the one hand, this scheme has relatively high requirements for the signal voltage to be converted, so that the previous electrical domain Processing puts forward very high requirements. On the other hand, if multi-bit analog-to-digital conversion is to be realized, the length of the modulator will double for each additional bit, so not only the manufacture of the modulator is more difficult, but also the modulation rate is also limited. will decrease, limiting the system bandwidth

Someone once proposed to use a modulator of the same length in Taylor's scheme, and double the signal voltage applied to the modulator to double the period of the modulation curve (refer to patents: Yang Yapei, Zhang Qianshu, Dai Jizhi, Zhang Xiaoxia, Liu Yongzhi, " An Integrated Optical M-Z Structure Analog-to-Digital Converter", Publication No. 1635417), but this puts forward higher requirements for the processing of the previous electrical signals, and also greatly limits the system bandwidth, and also puts forward higher requirements for the modulator. requirements

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