1. Field of the Disclosed Embodiments
The disclosure relates to incorporating an optical homodyne into a self-diffraction densitometer.
2. Introduction
A self-diffraction densitometer may require the detection of a laser-like signal beam of very low power. When the self-diffraction process is implemented in the mid-infra-red part of the spectrum, it will be limited by the thermal noise out of the silicon infra-red detector. Even with optimized detectors that are thermo-electrically cooled, this thermal noise determines the upper limit of the signal to noise ratios that can be achieved by previous laser self-diffraction processes.
Thus, a need exists for a means by which the signal to noise ratio imposed by the available infra-red detectors can be overcome.