precise laser wavelength measurement tagged posts

Wavemeter 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.