一种采用并行光强度调制器的模数转换方法

A New Approach for Analog to Digital Conversion Based on Double Parallel Optical Intensity Modulator

提出了一种采用并行光强度调制器实现移相光量化的方法。利用对光强度的衰减实现量化曲线的相移,解决了现有移相光量化方案中相位调制器对环境、温度较为敏感,量化曲线相移控制精度以及脉冲走离的问题。采用两个铌酸锂强度调制器并行连接,每个光耦合器分成4个通道,每个通道中插入光衰减器,通过调节光衰减器实现通道间调制曲线的相移,构成8通道4 bits的光量化器。实验中对10 GHz的正弦信号进行了光量化测试,量化结果的有效比特数(ENOB)为3.7 bits,仅低于理想分辨率0.3 bits。实验结果表明该方案可行,与一般移相光量化方案相比,具有较高的有效比特数。

A novel approach of a phase shifted all optical analog to digital converter with double parallel intensity modulator is proposed and demonstrated. The phase shift of quantization curve is simply realized by optical attenuation. The proposed scheme can solve the problem of pulse walk off, and low precision of phase shift in the present phase shifting quantization schemes as well as the influence of environment and temperature. In this scheme, the outputs of two parallel LiNbO3 intensity modulators are split into 4 channels with an optical attenuator inserted in each channel. By appropriately adjusting the optical attenuators, the phase shift between two adjacent channels is achieved, thus 8-channel optical quantizer is realized with resolution of 4 bits. In the experiment, a 10 GHz sinusoidal input signal is quantized using this scheme with an effective number of 3.7 bits. The deviation from the ideal case is only 0.3 bits. This result donates that the proposed approach is feasible, and has a relatively high effective number of bits compared with the present schemes.