Detection limits of an internal-reflection sensor for the optical beam deflection method.
The theoretical detection limit on angle deflection measurement when the quasi-critical internal-reflection method is used is calculated and compared with the more common method of using a bicell position-sensitive detector. Simple formulas for the sensitivity and resolution when the system is shot noise limited are given. It is shown that, even though the bicell detector is potentially much more sensitive for wide and well collimated beams, under typical laboratory restrictions, the internal reflection method may be more sensitive and have better resolution. It is argued that the internal-reflection method may be a tool in developing compact sensors based on the optical beam deflection method.
García-Valenzuela
A
A
Diaz-Uribe
R
R