Partial decorrelation enabled quasi-error-free speckle computational spectrometer based on ferroelectric material...

The speckle computational spectrometer features an ultra-compact footprint with performance comparable to that of the conventional bulk counterpart. Nonlinear optimization algorithms are commonly adopted to recover more wavelengths under test than the number of physical detection channels. This strategy can effectively expand the detection bandwidth but suffers from several drawbacks regarding signal reconstruction speed and signal recovery relying on prior knowledge of signal type (sparse or broadband signals). In this work, we demonstrate a design paradigm for on-chip speckle computational spectroscopy based on ferroelectric material with a large Pockels coefficient, which can efficiently reconstruct arbitrary signals without the need for an optimization process. Consequently, it can rapidly recover the incident signal without prior knowledge of the signal type before measurement. Our findings can potentially accelerate the applications of on-chip miniaturized spectrometers in the fields of biological sensing, light source characterization, quantum technology, material analysis, etc.