Femtosecond laser written scattering chip for high-resolution low-cost reconstructive spectrometry

The common challenge for reconstructive spectrometers is achieving high spectral resolution without sacrificing device stability, size and costs. Here a fully integrated scattering chip-based spectrometer build on Raspberry Pi platform is designed and implemented. It exhibits no dependence on temperature and humidity (22.7-23.8 degrees C and 39.5-41 % Rh), is confined in small space (box 50 x 35 x 35 mm) and can reconstruct spectra with resolution up to 0.05 nm (50 pm). The only instability: mechanical micro-movements were compensated by applying pixel binning and device could still reconstruct spectra from binned pictures as small as 32 x 24 pixels.