Time-Resolved Polarization of Luminescence Spectroscopy: An Accurate and Versatile Digital Instrument for the Sub-μs Time Domain

Abstract

An instrument is described for the measurement of circular and linear polarizations of the luminescence with a time resolution up to 50 ns. The spectrometer, which makes use of a 50-kHz photoelastic modulator and a differential photon-counting technique, is accurate and absolute and is capable of detecting small degrees of polarization. Making use of excitation light pulses which lie randomly in the modulator's duty cycle, the instrument can be readily interfaced with a variety of externally triggered or free running pulsed light sources.