title: Supercontinuum Fourier transform spectrometry with balanced detection on a single photodiode.
abstract: We demonstrate a method of combining a supercontinuum light source with a commercial Fourier transform spectrometer, using a novel approach to dual-beam balanced detection, implemented with phase-sensitive detection on a single light detector. A 40 dB reduction in the relative intensity noise is achieved for broadband light, analogous to conventional balanced detection methods using two matched photodetectors. Unlike conventional balanced detection, however, this method exploits the time structure of the broadband source to interleave signal and reference pulse trains in the time domain, recording the broadband differential signal at the fundamental pulse repetition frequency of the supercontinuum. The method is capable of real-time correction for instability in the supercontinuum spectral structure over a broad range of wavelengths and is compatible with commercially designed spectrometers. A proof-of-principle experimental setup is demonstrated for weak absorption in the 1500-1600 nm region.
authors: Division of Chemistry, Department of Energy and Photon Sciences, Brookhaven National Laboratory, Upton, New York 11973, USA.
authors: Vasily V
authors: VV
authors: Goncharov
authors: Division of Chemistry, Department of Energy and Photon Sciences, Brookhaven National Laboratory, Upton, New York 11973, USA.
authors: Gregory E
authors: GE
authors: Hall