Versatile digital lock-in detection technique: application to spectrofluorometry and other fields.

A digital lock-in detection technique which overcomes some practical limitations of the analog lock-in amplifiers is described. An example of implementation is given, based on multichannel pulse analyzers. Some representative results are reported for two typical application fields of lock-in techniques, namely optical spectrometry and semiconductor profiling with C-V techniques. Advantages and limitation of the technique are discussed as well as adaptation to various modulation waveforms.