Measurement of Infrared Photoluminescence Spectra by Gated Integration with Active Baseline Subtraction

On the basis of Fourier transform infrared (FTIR) spectroscopy, a method is implemented that enables measurements of infrared (IR) photoluminescence with a high reverse duty cycle of pump pulses, which decreases the uncontrolled heating of semiconductor structures by an excitation laser. The method was used to record IR photoluminescence spectra of test narrow-gap low-dimensional heterostructures in the wavelength range of 1–5 µm. It is determined that, at high reverse duty cycles of the reference pulse (greater than 20), the developed gated integration method has a better signal-to-noise ratio in the measured spectra than does the conventionally used synchronous detection (lock-in) method.