The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 19, 1991
Filed:
Mar. 28, 1990
Bertram C Johnson, Sunnyvale, US;
Richard L Herbst, Palo Alto, US;
Glen R Blevins, San Jose, CA (US);
Spectra Physics, Inc., Mountain View, CA (US);
Abstract
A Q-switch for a laser having a resonant cavity including an output coupler, a gain medium and a retro-reflecting mirror is mounted in the resonant cavity between the gain medium and the retro-reflecting mirror. The Q-switch comprises a polarizer and a phase retarding element (such as a Pockels cell) which includes a birefringent substrate for inducing a controllable phase retardation in the cavity mode in response to an applied electric field. A tiltable mount supports the phase retarding element so that the lasing axis lies essentially in a plane of the crystallographic axis 45.degree. from the direction of polarization, and lies at an adjustable angle relative to the crystallographic axis. A control circuit supplies an applied electric field within the substrate having a first magnitude in a first state and a second magnitude in a seocnd state. In the first state, the phase retarding element induces 90.degree. rotation in a round trip for the cavity mode. In the second state, the phase retarding element induces effectively no rotation (0.degree. or 180.degree.) for the cavity mode. Therefore, the resonant cavity achieves a high extinction ratio by proper adjustment of the adjustable angle.