Opt Lett. 2019 Mar 15;44(6):1367-1370. doi: 10.1364/OL.44.001367.
The measurement of the wavelength of light using speckle is a promising tool for the realization of compact and precise wavemeters and spectrometers. However, the resolution of these devices is limited by strong correlations between the speckle patterns produced by closely spaced wavelengths. Here, we show how principal component analysis of speckle images provides a route to overcome this limit. Using this, we demonstrate a compact wavemeter that measures attometer-scale wavelength changes of a stabilized diode laser, eight orders of magnitude below the speckle correlation limit.
利用散斑测量光的波长是实现紧凑、精确的波长计和分光计的一种很有前途的工具。然而，这些设备的分辨率受到由紧密间隔的波长产生的散斑图案之间的强相关性的限制。在这里，我们展示了如何对散斑图像进行主成分分析来克服这一限制。利用这一点，我们展示了一种紧凑的波长计，它可以测量稳定二极管激光器的 attometer 级别的波长变化，比散斑相关极限低八个数量级。
