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:
Jun. 17, 1997
Filed:
Apr. 03, 1995
Hagop Injeyan, Glendale, CA (US);
Randall J St Pierre, Santa Monica, CA (US);
TRW Inc., Redondo Beach, CA (US);
Abstract
Apparatus, and a related method, for compensating for birefringence introduced in a birefringent medium, such as a solid-state amplifier. The invention includes the combination of a quarter-wave plate, a Faraday rotator and a mirror, which may be a phase conjugation cell. Light passing through the quarter-wave plate is substantially circularly polarized, which is advantageous if the mirror is a phase conjugation cell using stimulated Brillouin scattering (SBS). A second pass through the quarter-wave plate provides a linearly polarized beam of which the polarization angle is orthogonally related to that of the original beam, to facilitate out-coupling of energy from the apparatus. The Faraday rotator effects a total polarization angle rotation of 90.degree. in two passes and helps compensate for birefringence when the beam is passed through the birefringent medium again on the return pass. The combination of the quarter-wave plate and the Faraday rotator provides better birefringence cancellation than either element acting alone.