提出了一种基于空间正弦相位调制来消除镜像的复谱域光学相干层析(OCT)成像的方法。在参考臂引入正弦相位调制, 对得到的干涉光谱进行谐波分析, 获取干涉信号的两个正交分量, 以构成复数干涉信号。复数干涉信号的傅里叶变换, 可以消除复共轭镜像以及自相关项和直流项。利用建立的谱域OCT系统对平面镜样品成像, 验证了方法的可行性, 复共轭抑制率可达35 dB。通过在参考臂实施正弦相位调制的同时对样品进行横向扫描, 可以实现高速二维成像, 而且成像深度范围扩大到原来的两倍。

A complex full-range spectral domain optical coherence tomography system based on spatial sinusoidal phase modulation is presented. Through sinusoidal phase modulation in the reference arm, the quadrature components of interferogram can be obtained by harmonic detecting. Then the complex-conjugate ambiguity, DC term and autocorrelation noise are eliminated by the Fourier transform of complex interferogram. A complex-conjugate rejection ratio of about 35 dB is achieved. Furthermore, in our experiment, high speed complex-conjugate resolved imaging is performed by combining the sinusoidal phase modulation and transversal scanning.