Department of Mechanical, Industrial and Aerospace Engineering (MIAE), Concordia University, Montreal, QC H3G 1M8, Canada.
Sensors (Basel). 2021 Sep 28;21(19):6463. doi: 10.3390/s21196463.
We report the design of a high-efficiency spectral-domain spectrometer with cylindrical optics for line scanning optical coherence tomography (OCT). The spectral nonlinearity in k space (wavenumber) lowers the depth-dependent signal sensitivity of the spectrometers. For linearizing, in this design, grating and prism have been introduced. For line scanning, a cylindrical mirror is utilized in the scanning part. Line scanning improves the speed of imaging compared to fly-spot scanning. Line scanning OCT requires a spectrometer that utilizes cylindrical optics. In this work, an optical design of a linear wavenumber spectrometer with cylindrical optics is introduced. While there are many works using grating and prism to linearize the K space spectrometer design, there is no work on linearizing the k-space spectrometer with cylindrical optics for line scanning that provides high sensitivity and high-speed imaging without the need for resampling. The design of the spectrometer was achieved through MATLAB and ZEMAX simulations. The spectrometer design is optimized for the broadband light source with a center wavelength of 830 ± 100 nm (8.607 μm-1- 6.756 μm-1 in k-space). The variation in the output angle with respect to the wavenumber can be mentioned as a nonlinearity error. From our design results, it is observed that the nonlinearity error reduced from 147.0115 to 0.0149 Δθ*μm within the wavenumber range considered. The use of the proposed reflective optics for focusing reduces the chromatic aberration and increases image quality (measured by the Strehl ratio (SR)). The complete system will provide clinicians a powerful tool for real-time diagnosis, treatment, and guidance in surgery with high image quality for in-vivo applications.
我们报告了一种具有圆柱光学的高效率光谱域光谱仪的设计，用于线扫描光学相干断层扫描（OCT）。光谱非线性在 k 空间（波数）中降低了光谱仪对深度相关信号的灵敏度。为了线性化，在这个设计中，引入了光栅和棱镜。对于线扫描，在扫描部分使用了一个圆柱形镜子。与飞点扫描相比，线扫描提高了成像速度。线扫描 OCT 需要使用圆柱光学的光谱仪。在这项工作中，介绍了一种具有圆柱光学的线性波数光谱仪的光学设计。虽然有许多使用光栅和棱镜来线性化 K 空间光谱仪设计的工作，但没有关于用于线扫描的具有圆柱光学的线性化 k 空间光谱仪的工作，该光谱仪无需重采样即可提供高灵敏度和高速成像。光谱仪的设计通过 MATLAB 和 ZEMAX 模拟实现。该光谱仪设计针对中心波长为 830 ± 100nm（k 空间中的 8.607μm-1-6.756μm-1）的宽带光源进行了优化。输出角度随波数的变化可以被认为是非线性误差。从我们的设计结果可以看出，在考虑的波数范围内，非线性误差从 147.0115 减小到 0.0149Δθ*μm。使用所提出的反射光学元件进行聚焦可以减少色差并提高图像质量（通过斯特列尔比（SR）测量）。完整的系统将为临床医生提供一种强大的工具，用于实时诊断、治疗和手术指导，并提供高质量的体内应用图像。
