A HARDWIRED DIGITAL PHASE-SENSITIVE DETECTOR APPLIED TO SPECTROSCOPY

In this work a new digital PSD is described. It has been designed mainly for infrared (IR) spectroscopy where only low-efficiency detectors are available and a great deal of noise is usually present. Nevertheless the system is able to collect the signal given by any digital or analog detector. Hence, it can be useful for a wide range of radiation spectra. The PSD uses dedicated hardware rather than a general-purpose (but usually more limited performance) microprocessor as its basis. Unlike sample-and-hold techniques, this PSD picks up the signal almost continuously in order to make full use of it. Interesting features of the present apparatus are its low cost, versatility and ease of construction.