Supercontinuum sources for visible light spectral domain OCT (SDOCT) are noisy and often expensive. Balanced detection can reduce excess noise, but is rarely used in SDOCT. Here, we show that balanced detection can achieve effective excess noise cancellation across all depths if two linear array spectrometers are spectrally well-matched. We propose excess noise correlation matrices as tools to achieve such precise spectral matching. Using optomechanical adjustments, while monitoring noise correlations, we proactively match wavelength sampling of two different spectrometers to just a few picometers in wavelength, or 0.001% of the overall spectral range. We show that proactively-matched spectrometers can achieve an excess noise suppression of more than two orders-of-magnitude in balanced visible light OCT, outperforming simple retrospective software calibration of mismatched spectrometers. High noise suppression enables visible light OCT of the mouse retina at 70 kHz with 125 microwatts incident power, with an inexpensive, 30 MHz repetition rate supercontinuum source. Averaged images resolve the retinal pigment epithelium in a highly pigmented mouse strain.

中文翻译：

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用于平衡可见光光学相干断层扫描 (OCT) 中过度噪声抑制的主动光谱仪匹配

用于可见光光谱域 OCT (SDOCT) 的超连续谱光源噪声大且价格昂贵。平衡检测可以减少多余的噪声，但在 SDOCT 中很少使用。在这里，我们表明，如果两个线性阵列光谱仪在光谱上匹配良好，则平衡检测可以在所有深度上实现有效的过量噪声消除。我们建议使用过量噪声相关矩阵作为实现这种精确频谱匹配的工具。使用光机械调整，在监测噪声相关性的同时，我们主动将两个不同光谱仪的波长采样匹配到仅几个皮米的波长，或整个光谱范围的 0.001%。我们表明，主动匹配的光谱仪可以在平衡的可见光 OCT 中实现超过两个数量级的过量噪声抑制，优于不匹配光谱仪的简单回顾性软件校准。高噪声抑制使小鼠视网膜的可见光 OCT 频率为 70 kHz，入射功率为 125 微瓦，使用廉价的 30 MHz 重复率超连续谱源。平均图像解析高色素小鼠品系中的视网膜色素上皮。