Demonstration of time-of-flight technique with all-optical modulation and MCT detection in SWIR/MWIR range

We report a feasibility study of Time-of-Flight technique in Short- and Mid-Wavelength Infrared spectral region using a Mercury Cadmium Telluride detector. For the demonstration we employed an all-optical modulator operated by optical pumping with 800 nm, 100 femtosecond pulses and measured the broadening of the signal pulses traversing through a few centimetres of silica rod. The measured signal was analysed to reconstruct the pulse broadening and to retrieve the group velocity dispersion of silica. We show that in Time-of-Flight measurements based on all-optical modulation in combination with Mercury Cadmium Telluride detector, the limiting resolution factor is the speed of the modulator rise time governed by the optical pump.