Research And Design Of Integrated Optical Waveguide Electro-optical Analog-to-digital Converter

Digital signal has many advantages in signal processing, including the duplication of programming convenient, dynamic range and non-linearity make their own determination, long-term storage without distortion, which making digital signal processing technology gradually replaces the analog system. And as the core device of converting analog signals to digital signals, ADC (analog-to-digital converters) is very important to the system.This paper first summarized the electro-optic A/D (analog/digital) converter principle and development overview, described the advantages of electro-optic A/D converter compared with electric- A/D converter, research significance and application prospects. Then the paper pointed out that the integrated optical waveguide A/D converter is a promising electro-optical ADC based on the structure and properties of electro-optic ADC. The principle and performance parameters of the electrode double-type optical ADC was also analyzed.Then this paper analyzed the Lithium Niobate (LiNbO₃) optical waveguide electro-optical ADC in detail, including its general principles and structure.Thirdly this paper analyzed the factors of the ADC including laser pulse, laser pulse width, bend loss and transmission loss. M-Z electro-optical modulator ADC program was the overall design, the author simulated the transmission loss of the M-Z structural waveguide electro-optical A/D converter. The results show that the transmission loss mainly comes from the bend loss, linear loss and transmission loss of Y branch.Therefore according to the result of simulation the author designed several different waveguides structures by using BPM method and effective index method. And after comparison with each other the most reasonable M-Z structure was found. Then by choosing different half-wave voltage, the relationship between the bit number and half-wave voltage of A/D converter was simulated and discussed. After the discussion about the bandwidth of the A/D converter, a reasonable result was obtained.According to these results the parameters of the A/D converter was optimized and a reasonable device was obtained. At last, the results verified the feasibility of the scheme.