A fast tunable high resolution filter

We demonstrated experimentally the feasibility of a fast tuning high resolution filter with a good flatness. The device could easily be adapted to applications in spectroscopy or in DWDM communications (tunable lasers or filters for instance). Acousto-optic filtering has been extensively studied because its tuning rapidity makes it very useful for many applications. Nevertheless, its resolution is often not sufficient in the fields of telecommunication or spectrometry. The proposed grating-assisted acousto-optical filtering technique combines the high resolution of diffraction gratings (/spl sim/10 pm) and the tuning swiftness of acousto-optics (/spl mu/s).