title: Note: improved sensitivity of photoreflectance measurements with a combination of dual detection and electronic compensation.
abstract: A setup is described for performing photoreflectance (PR) measurements using two photodetectors, wherein the photodetectors need not be identical. The second detector monitors the photoluminescence and scattered pump laser background signal in real time. It is then eliminated from the measured PR signal using electronic circuits that compensate for amplitude and phase differences between the background signals from the two detectors. The technique overcomes the adverse effect of short-term fluctuations in the pump laser intensity. The signal-to-noise ratio is shown to improve significantly, enabling measurement of weak PR signals.
authors.affiliation: Department of Condensed Matter Physics and Material Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India.
authors.forename: Amlan
authors.initials: A
authors.lastname: Mukherjee
authors.forename: Sandip
authors.initials: S
authors.lastname: Ghosh
authors.forename: Vasam
authors.initials: V
authors.lastname: Sugunakar