320-Channel Dual Phase Lock-in Optical Spectrometer
Abstract
The development of a multiple-channel lock-in optical spectrometer (LIOS) is presented, which enables parallel phase-sensitive detection at the output of an optical spectrometer. The light intensity from a spectrally broad source is modulated at the reference frequency, and focused into a high-resolution imaging spectrometer. The height at which the light enters the spectrometer is controlled by an acousto-optic deflector, and the height information is preserved at the output focal plane. A two-dimensional InGaAs focal plane array collects light that has been dispersed in wavelength along the horizontal direction, and in time along the vertical direction. The data is demodulated using a high performance computer-based digital signal processor. This parallel approach greatly enhances (by more than 100x) the speed at which spectrally resolved lock-in data can be acquired. The noise performance of a working system optimized for the 1300 nm wavelength range is analyzed using a laser diode light source. Time-resolved absorption traces are obtained for InAs quantum dots embedded in a GaAs matrix, and for dispersed films of PbSe nanocrystals.
Cite
@article{arxiv.cond-mat/0405074,
title = {320-Channel Dual Phase Lock-in Optical Spectrometer},
author = {P. S. Fodor and S. Rothenberger and J. Levy},
journal= {arXiv preprint arXiv:cond-mat/0405074},
year = {2009}
}
Comments
27 pages, 11 figures, submitted to the journal "Review of Scientific Instruments"