基于FPGA的单探测器偏振OCT信号解调系统设计

FPGA-based Signal Demodulation System of Single-detector Polarization-sensitive OCT

为了探测组织的双折射性质,搭建了以FPGA作为处理芯片的单探测器偏振OCT系统。FPGA利用内部RAM、乘法器、IP核和宏功能模块构建数字正交解调电路,提取偏振OCT干涉信号,获取组织的反射率信息和双折射信息。获取的数据经USB2.0接口送入计算机显示。对玻片和生物组织进行信号解调实验,结果表明,系统能够对偏振OCT信号进行解调,而且能够持续稳定工作。

In order to achieve the birefringence properties of biological tissues,a single-detector polarization-sensitive OCT system is built,using the FPGA as main processor.FPGA extracts the envelope of digital PS-OCT interference signal and gets information of biological tissue reflectivity and birefringence by its internal digital quadrature demodulation circuit which is implemented by internal ROM,multiplier,IP core and megefunctions in FPGA.Data obtained is sent into the computer to display by USB2.0 interface.Experiment results on signal demodulation of the coverslip and biological tissue showed that the system has ability to demodulate the polarization-sensitive OCT signal,and the system works continuously and stability.