Abstract

A fast low-cost digital lock-in has been developed for photon counting systems. Rates up to 5 MHz will be accepted by the input. The number of counts for positive and negative modulation are subtracted, and the result is emitted as a constant chain of pulses with a frequency of 5 MHz. The modulation frequency for gating the countup–countdown function is limited only by the TTL devices. For the developer’s purpose 36 Hz has been used.

© 1977 Optical Society of America

Integrated construction of low-cost gas lasers

Michael E. Fein and Charles W. Salisbury
Appl. Opt. 16(8) 2308-2314 (1977)

Photodiode preamplifier systems: low-noise positive-feedback

E. J. Fjarlie
Appl. Opt. 16(2) 385-392 (1977)

Digital lock-in technique for measurement of polarization of radiation

C. Denise Caldwell
Opt. Lett. 1(3) 101-103 (1977)

Fast-moving suspended particles: measurements of their size and velocity

Jin Wu
Appl. Opt. 16(3) 596-600 (1977)

Near infrared astronomical light collector

Jean-Pierre Chevillard, Pierre Connes, Maximilien Cuisenier, Jean Friteau, and Claude Marlot
Appl. Opt. 16(7) 1817-1833 (1977)