Precision laser beam deflection detector

Claim 1

In an optical measuring system including a source of coherent light, an electro-optical system for quantitively determining deflection or displacement of the light output from said source of coherent light and having an optical axis comprising: polarizer means located on the optical axis of the electro-optical system for establishing an axis of polarization for the source of coherent light; a Faraday rod having non-parallel entrance and exit faces spaced apart along a longitudinal axis which is located on the optical axis of the electro-optical system to transmit the polarized output from the polarizer means through a predetermined length thereof; analyzer means located on the optical axis of the electro-optical system and positioned for receiving the light output from said Faraday rod; electro-optical detector means located on the optical axis of the electro-optical system in operative relation with respect to said analyzer means for intercepting the output therefrom and for generating an electrical analog therefrom; amplifier means connected to said electro-optic detector means for amplifying the electrical analog output therefrom and for developing a control signal therefrom; control means operatively connected to said amplifier means for receipt of said control signal therefrom and positioned in operative relation to said Faraday rod for control thereof; and measuring means indirectly connected to said control means for sensing and displaying the magnitude of the control signal supplied thereto by said amplifier means, whereby a predetermined optical condition within said optical measuring system may be maintained as an indication of optical activity within the system.