Spectra-physics Gmbh

Lightwave Electronics Corporation

David C Gerstenberger

Thomas James Kane

Richard W Wallace

Marc K Von Gunten

Benjamin H Cook

Apparatus and method for modulating the phase or the amplitude of a monochromatic light beam, the apparatus including in one embodiment a Mach-Zehnder interferometer that consists of two beam splitters or beam combiners, a fully reflective mirror and an electro-optical crystal for modulation of one of two beam components. The electro-optical crystal serves as an optical resonator for the portion of the light beam admitted into the crystal material, using total internal reflection of the light beam from two or more of the crystal surfaces. The crystal has a high finesse so that a relatively small change in voltage applied across the crystal produces a large (.apprxeq.180.degree.) change in the external phase shift associated with the modulated component of the light beam. The modulated and unmodulated light beam components may be recombined for purposes of communication of information, using the mutual extinction of the two beam components when the optical phase shift between the two beam components is approximately 180.degree.. Transverse or longitudinal electro-optical materials can be used for the crystal, and the driving voltages required are less than 50 volts in some configurations. Communications at frequency up to and beyond 1 GHz. are possible.

Resonant phase modulator

A wavelength selective mirror provides single wavelength operation of a gas laser. In a specific embodiment an output coupler optical interference coating allows oscillation of the 488.0 nanometer line of the Argon ion laser blue/green spectrum while suppressing all other lines in that spectrum, particularly adjacent lines at 476.5 nanometers and 496.5 nanometers.

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Mountain View, CA, United States of America

David C Gerstenberger