Fig. 4

Measurement results of the spectrum reconstruction of a tunable laser source. a Reconstructed spectra of the laser as it was tuned from 810 nm to 870 nm in 10 nm increments, using Penrose-Moore pseudoinverse and LASSO regression methods. b Amplitude variation of the reconstructed peak compared to the power meter read-outs. c Reconstructed spectra of the sum of output powers from two laser measurements, centered at 850 nm and separated by 0.5 nm to 0.1 nm, with 0.1 nm steps (left to right columns). The upper row shows reconstructions by Penrose-Moore pseudoinverse, while the lower row shows reconstruction using LASSO regression