基于快速扫描光学延迟线谐振扫描的相位调制方法

提出利用快速扫描光学延迟线(Rapid Scanning Optical Delay Line,RSOD)作为光学相干层析成像(Optical Coherence Tomography,OCT)系统的相位调制器，并采用正弦驱动方式(谐振扫描)来提高扫描频率，进而实现高频相位调制的方法.介绍了基于RSOD相位调制器的干涉信号包络解调方法，分析了大振镜低频率线性驱动、小振镜高频线性驱动和大振镜高速正弦驱动三种实施方案对OCT性能的影响，并针对谐振扫描方案中轴向扫描的非线性提出了图像畸变定量校正的方法.结果表明:RSOD大振镜谐振扫描的模式能够兼顾系统成像速度、成像范围以及系统信噪比的要求，是一种行之有效的相位调制方法.

Phase Modulation by Resonant Driving of the Galvo in Rapid Scanning Optical Delay Line

Rapid scanning optical delay line (RSOD) is proposed as the phase modulator in Optical Coherence Tomography (OCT).A sinusoidal waveform (resonant scan ) is applied to improve scanning rate,and high frequency phase modulation is achieved. Envelop demodulation method of the interference signal corresponding to RSOD-based phase modulator was introduced. Analysis on OCT performances in three different implementation schemes including linear actuated large galvomirror,linear actuated small galvomirror and sinusoidal actuated large galvomirror was carried out. Approach for quantitative correction of image distortion due to nonlinear depth scanning was put forward. Results show that a high-speed resonant scanner with a large galvamirror in RSOD is a feasible approach for phase modulator required in real-time OCT for heterodyne detection which is able to satisfy the demand of imaging rate,imaging range and signal-to-noise.