Cascade structural LiNbO3 waveguide electro-optic analog-digital conversion

Abstract

The invention provides an electro-optic analog-digital conversion method based on cascade structural LiNbO3 waveguide M-Z intensity modulator array; by arranging the number and direct current polarization of M-Z intensity modulators in the cascade structural LiNbO3 waveguide M-Z intensity modulator array, an output light intensity function of corresponding bits is obtained; identical modulation signal voltage is applied on each M-Z modulator of the cascade structural LiNbO3 waveguide M-Z intensity modulator array to carry out intensity modulation on the sampling light pulse so as to obtain light sampling of the modulation signal; light threshold is set to obtain phase bit code of the sampling light pulse followed by light-electricity conversion and comparison to obtain the phase bit code, thus realizing electro-optic analog-digital conversion. The electro-optic analog-digital conversion method based on cascade structural LiNbO3 waveguide M-Z intensity modulator array provided by the invention enhances preciseness of analog-digital conversion by adding number of cascade intensity modulators, overcomes the limit of Taylor scheme on sampling preciseness, which is mainly caused by index increase of electrode length along with the increase of bits. On the other hand, the invention inherits the characteristics of high sampling velocity of light sampling, thus having the characteristics of high sampling preciseness and high sampling velocity.

Description

technical field [0001] The invention belongs to the field of optoelectronic technology and the field of integrated optical waveguide devices, in particular to LiNbO with a cascaded structure 3 Research on waveguide-optic analog-to-digital conversion method. Background technique [0002] An analog-to-digital converter (ADC) is a device that converts an analog signal into a digital signal. The analog-to-digital conversion process is generally divided into four steps: sampling, holding, quantization, and encoding. Sampling rate and resolution are two of the most important parameters for measuring the performance of an analog-to-digital converter (ADC). [0003] Generally, the performance of an analog-to-digital converter (ADC) is mainly determined by the two most important parameters of sampling rate and resolution. The sampling rate is mainly determined by the sampling time of the A / D converter, and the commonly used units are KS / s and MS / s. Resolution, also known as preci...

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Problems solved by technology

[0011] However, the Taylor scheme is limited by the device parameters in improving the conversion accuracy. It requires the electrode length of the intensity modulator to increase exponentially with the number of digits. Therefore, the design of a 5-bit photoelectric analog-to-digital converter using the Taylor scheme requires the electrode length to reach 16 times the basic length. It is very difficult to design a high-precision electro-optical analog-to-digital converter using the Taylor scheme

At the same time, due to the exponential increase of the electrode length, the transit time of the light pulse is also extended, which limits the frequency of the highest modulation signal.

[0012] In short, the current development direction of analog-to-digital converters is to improve the conversion accuracy and increase the sampling rate at the same time, but the current electronic ADC can not keep up with the development speed of high-speed digital signal processing, so it is necessary to develop optoelectronic ADCs, and at the same time overcome the requirements of optoelectronic ADCs for devices Complexity and Difficulty Difficult to Miniaturize

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