Proof of concept for ultrahigh resolution photonic spectral processor

We propose a novel photonic spectral processor which overcomes current 0.8GHz spectral resolution limitation. The new spectral processor uses a Fabry Perot interferometer array located before the dispersive element of the system, thus significantly improving the spectral separation resolution, which is now limited by the Fabry Perot interferometers' full width at half maximum rather than the dispersive element's spectral resolution. A proof of concept experiment was performed utilizing two Fabry-Perot interferometers and a diffractive optical grating with a spectral resolution of 6.45GHz, achieving high spectral resolution of 577MHz. Further improvement of the experimental setup can result in resolution of about 50MHz.