Improved Time-resolved Fourier Spectroscopy

Abstract

Fourier spectroscopy is widely acknowledged as a powerful tool for steady-signal spectroscopy. It is becoming popular also for time-resolved measurements with step-scan interferometers providing for the widest range of possible time constants and repetition rates. The simpler, more numerous continuously scanning interferometers have seemed less suitable for time-resolved measurements because such data acquisition needs to be more or less closely synchronized to the continuous stream of sampling requests issued by these instruments. Of the several schemes for TRS with continuous-scan instruments, the interleaved or stroboscopic technique least restricts the time constant and repetition rate of the transient events, but this method is prone to artifacts and noise [1,2,3]. Small variations of the interferometer-mirror speed are a source of noise and possibly artifacts [3,4], Our “Event-Locked” data acquisition / analysis method eliminates these problems by reducing the need to synchronize the data acquisition to the scanning motion of the mirror, which simultaneously simplifies the experiment [5].