Kk. Geerinck et al., SHORT-PULSE EFFECTS IN FIR OPTICAL SATURATION - SHALLOW DONORS IN SILICON, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 341(1-3), 1994, pp. 162-164
Optical saturation experiments are widely used to determine the lifeti
me T1 of photoexcited states. Unfortunately, such experiments require
the simultaneous knowledge of the phase relaxation time T2 and an abso
lute calibration of the light intensity I in the sample, rendering the
analysis of such experiments hazardous. The present contribution illu
strates how this problem can be solved by using free electron lasers l
ike FELIX yielding trains of short pulses instead of quasi-cw radiatio
n.