Opt Lett. 2020 Jul 1;45(13):3443-3446. doi: 10.1364/OL.393162.
Intensity levels allowed by safety standards (ICNIRP or ANSI) limit the amount of light that can be used in a clinical setting to image highly scattering or absorptive tissues with optical coherence tomography (OCT). To achieve high-sensitivity imaging at low intensity levels, we adapt a detection scheme-which is used in quantum optics for providing information about spectral correlations of photons-into a standard spectral domain OCT system. This detection scheme is based on the concept of dispersive Fourier transformation, where a fiber introduces a wavelength-dependent time delay measured by a single-pixel detector, usually a high-speed photoreceiver. Here, we use a fast superconducting single-photon detector SSPD as a single-pixel detector and obtain images of a glass stack and a slice of onion at the intensity levels of the order of 10 pW. We also provide a formula for a depth-dependent sensitivity falloff in such a detection scheme, which can be treated as a temporal equivalent of diffraction-grating-based spectrometers.
安全标准（ICNIRP 或 ANSI）允许的强度限制了在临床环境中使用光相干断层扫描（OCT）对高散射或高吸收组织成像的光量。为了在低强度水平下实现高灵敏度成像，我们将一种检测方案——该方案用于量子光学以提供光子光谱相关性的信息——应用于标准光谱域 OCT 系统中。这种检测方案基于色散傅里叶变换的概念，其中光纤引入一个由单像素探测器测量的与波长相关的时间延迟，通常是一个高速光接收器。在这里，我们使用快速超导单光子探测器 SSPD 作为单像素探测器，并在 10pW 量级的强度水平下获得了玻璃叠层和洋葱切片的图像。我们还提供了这种检测方案中深度相关灵敏度下降的公式，该公式可以看作是基于衍射光栅的光谱仪的时间等效物。
