Choma Michael A, Yang Changhuei, Izatt Joseph A
Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA.
Opt Lett. 2003 Nov 15;28(22):2162-4. doi: 10.1364/ol.28.002162.
We describe fiber-based quadrature low-coherence interferometers that exploit the inherent phase shifts of 3 x 3 and higher-order fiber-optic couplers. We present a framework based on conservation of energy to account for the interferometric shifts in 3 x 3 interferometers, and we demonstrate that the resulting interferometers provide the entire complex interferometric signal instantaneously in homodyne and heterodyne systems. In heterodyne detection we demonstrate the capability for extraction of the magnitude and sign of Doppler shifts from the complex data. In homodyne detection we show the detection of subwavelength sample motion. N x N (N > 2) low-coherence interferometer topologies will be useful in Doppler optical coherence tomography (OCT), optical coherence microscopy, Fourier-domain OCT, optical frequency domain reflectometry, and phase-referenced interferometry.
我们描述了基于光纤的正交低相干干涉仪，该干涉仪利用了3×3及更高阶光纤耦合器的固有相移。我们提出了一个基于能量守恒的框架，用于解释3×3干涉仪中的干涉相移，并证明所得干涉仪能在零差和外差系统中即时提供整个复干涉信号。在外差检测中，我们展示了从复数据中提取多普勒频移大小和符号的能力。在零差检测中，我们展示了对亚波长样本运动的检测。N×N（N>2）低相干干涉仪拓扑结构将在多普勒光学相干断层扫描（OCT）、光学相干显微镜、傅里叶域OCT、光学频域反射测量和相位参考干涉测量中发挥作用。
