1 April 1992 Laser heterodyning detector for frequency-domain ultrafast spectroscopy
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The attainable frequency range of ordinary heterodyning and super-heterodyning frequency- domain fluorescence instrumentation is limited by the response of the optical detector rather than by the harmonic content of the light source. The replacement of the photomultiplier detector by a 6 (mu) microchannel plate detector has improved the frequency response from 500 MHz to 10 GHz. A new method is developed to detect fast, excited state processes by extending to the frequency-domain the well known pump/probe (absorption) technique used in the time-domain. The upper frequency limit attainable with this method is limited only by the pulse width of the light sources. For picosecond pulse lasers this limit extends to hundreds of gigahertz. A theoretical determination of the basic equations is given, and data are shown for the excited state decay of a rhodamine 6G sample in ethylene glycol.
© (1992) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Keith M. Berland, Keith M. Berland, Enrico Gratton, Enrico Gratton, Martin J. vandeVen, Martin J. vandeVen, } "Laser heterodyning detector for frequency-domain ultrafast spectroscopy", Proc. SPIE 1640, Time-Resolved Laser Spectroscopy in Biochemistry III, (1 April 1992); doi: 10.1117/12.58229; https://doi.org/10.1117/12.58229

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