TIME AND FREQUENCY-RESOLVED PHOTOLUMINESCENCE UP CONVERSION USING BROADLY TUNABLE PICOSECOND INFRARED PULSES

A simultaneous time and frequency-resolved photoluminescence setup bas ed upon the concept of sum-frequency generation has been developed usi ng the parallel collection capabilities of a liquid nitrogen cooled, h igh quantum efficiency charge coupled device (CCD) detector. This up c onversion system can provide excellent time resolution (down to simila r to 100 fs), when the detector is used in the single channel mode, wi th large dynamic range. When the CCD detector is used in its full capa city (1024 channels), wide spectral range as well as temporal informat ion are obtained simultaneously from the up-converted signal, thus pro viding important information on the dynamics of various emission peaks which can occur simultaneously. Together with this, an efficient meth od for generation of high repetition rate, low energy infrared light b etween 1.44 and 1.62 mu m is described. The technique uses difference frequency mixing of the fundamental wavelength of a mode-locked Nd:ytt rium aluminum garnet laser and the output of a synchronously pumped Rh odamine 640 dye laser in a 10 mm long lithium triborate crystal. This source was then used to performed cw and time-resolved up-conversion p hotoluminescence measurements on a 1.54 mu m emitting InGaAsP epitaxia l layer. (C) 1998 American Institute of Physics.