Chang Lantian, Weiss Nicolás, van Leeuwen Ton G, Pollnau Markus, de Ridder René M, Wörhoff Kerstin, Subramaniam Vinod, Kanger Johannes S
Opt Express. 2016 Jun 13;24(12):12635-50. doi: 10.1364/OE.24.012635.
We demonstrate an integrated optical probe including an on-chip microlens for a common-path swept-source optical coherence tomography system. This common-path design uses the end facet of the silicon oxynitride waveguide as the reference plane, thus eliminating the need of a space-consuming and dispersive on-chip loop reference arm, thereby obviating the need for dispersion compensation. The on-chip micro-ball lens eliminates the need of external optical elements for coupling the light between the chip and the sample. The use of this lens leads to a signal enhancement up to 37 dB compared to the chip without a lens. The light source, the common-path arm and the detector are connected by a symmetric Y junction having a wavelength independent splitting ratio (50/50) over a much larger bandwidth than can be obtained with a directional coupler. The signal-to-noise ratio of the system was measured to be 71 dB with 2.6 mW of power on a mirror sample at a distance of 0.3 mm from the waveguide end facet. Cross-sectional OCT images of a layered optical phantom sample are demonstrated with our system. A method, based on an extended Fourier-domain OCT model, for suppressing ghost images caused by additional parasitic reference planes is experimentally demonstrated.
我们展示了一种用于共光路扫频光源光学相干断层扫描系统的集成光学探头，其中包括一个片上微透镜。这种共光路设计采用氮氧化硅波导的端面作为参考平面，从而无需占用空间且具有色散的片上环形参考臂，进而无需色散补偿。片上微球透镜消除了在芯片与样品之间耦合光所需的外部光学元件。与没有透镜的芯片相比，使用该透镜可使信号增强高达37 dB。光源、共光路臂和探测器通过一个对称Y形结连接，该结在比定向耦合器所能获得的带宽大得多的带宽上具有与波长无关的分光比（50/50）。在距波导端面0.3 mm处的镜面样品上，当功率为2.6 mW时，该系统的信噪比测量值为71 dB。我们的系统展示了分层光学仿体样品的横截面光学相干断层扫描图像。通过实验展示了一种基于扩展傅里叶域光学相干断层扫描模型的方法，用于抑制由额外寄生参考平面引起的重影图像。
