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:
Aug. 14, 1990
Filed:
Apr. 25, 1988
Joseph W Kantorski, Southbridge, MA (US);
Klaus Hachfeld, Sturbridge, MA (US);
James L Hobart, Los Altos Hills, CA (US);
Coherent, Inc., Palo Alto, CA (US);
Abstract
A rod laser having a ring cavity configuration, and including a polarization rotator to compensate for birefringence of the laser's rod. Preferably, the rotator is a 90.degree. crystal quartz rotator. In a preferred embodiment, the ring laser is a stable quasi-unidirectional, non-confocal solid state ring laser. A telescope, including at least two lenses with variable inter-lens spacing, is preferably positioned in the laser beam path as closely as possible to the laser rod. The spacing between the telescope lenses is preferably controlled by a servo mechanism. In a preferred embodiment, a power density detector is provided for producing a beam power signal, and a means (which may include a microprocessor) coupled to the power density detector generates a servo mechanism feedback control signal from the beam power signal. Since the system of the invention maintains a high quality output beam having low far-field beam divergence and small laser beam focal spot diameter, over a wide and varying range of output beam power, the output beam is particularly useful for such applications as high speed drilling, welding, and cutting.