Instrument Response in Ultrafast VO₂ Spectroscopy

This technical note examines how finite instrument response affects decay times estimated from ultrafast measurements of vanadium dioxide (VO₂). It reviews selected studies of photoinduced changes in VO₂ and uses a simulated pump–probe signal to isolate the effect of limited time resolution. In the worked example, a 35 fs decay broadened by a Gaussian instrument response with a 100 fs full width at half maximum yields a fitted decay time of 81.84 fs when the response is omitted from the fit. Accounting for the instrument response recovers the original 35 fs decay time.