Across optics and photonics, excess intensity noise is often considered a liability. Here, we show that excess noise in broadband supercontinuum and superluminescent diode light sources encodes each spectral channel with unique intensity fluctuations, which actually serve a useful purpose. Specifically, we report that excess noise correlations can both characterize the spectral resolution of spectrometers and enable cross-calibration of their wavelengths across a broad bandwidth. Relative to previous methods that use broadband interferometry and narrow linewidth lasers to characterize and calibrate spectrometers, our approach is simple, comprehensive, and rapid enough to be deployed during spectrometer alignment. First, we employ this approach to aid alignment and reduce the depth-dependent degradation of the sensitivity and axial resolution in a spectrometer-based optical coherence tomography (OCT) system, revealing a new outer retinal band. Second, we achieve a pixel-to-pixel correspondence between two otherwise disparate spectrometers, enabling a robust comparison of their respective measurements. Thus, excess intensity noise has useful applications in optics and photonics.

在光学和光子学领域，过高的强度噪声通常被认为是一种负担。在这里，我们表明宽带超连续谱和超辐射二极管光源中的过量噪声以独特的强度波动对每个光谱通道进行编码，这实际上起到了有用的作用。具体来说，我们报告说，过多的噪声相关性既可以表征光谱仪的光谱分辨率，又可以在宽带宽内对其波长进行交叉校准。相对于以前使用宽带干涉测量和窄线宽激光器来表征和校准光谱仪的方法，我们的方法简单、全面且快速，足以在光谱仪对准期间部署。首先，我们采用这种方法来帮助对准并减少基于光谱仪的光学相干断层扫描（OCT）系统中灵敏度和轴向分辨率的深度依赖性退化，从而揭示新的视网膜外带。其次，我们在两个不同的光谱仪之间实现了像素到像素的对应，从而能够对它们各自的测量结果进行稳健的比较。因此，过量强度噪声在光学和光子学中具有有用的应用。