| The new wavemeter experimental setup. (a) Laser light is delivered into an integrating sphere (S) of diameter Dsphere, via an angled single mode fibre (SMF), where it undergoes numerous scattering events. A camera (C) located at a distance L from the integrating sphere observation port captures the speckle patterns. A wavemeter or Fabry–Perot interferometer (REF) is used to benchmark the speckle wavemeter. (b) An example of a speckle pattern captured by the camera at a wavelength of 780 nm with an image size of 512 × 512 pixels (with individual pixels of 4.5 × 4.5 μm2). The white scale bar denotes 200 pixels, and the colour bar shows the intensity in normalized units. Courtesy M Squared / St Andrews University / Nature Communications doi:10.1038/ncomms15610. |
