USA As Represented by Secretary of the Navy

David G Cooper

James L Dexter

John F Reintjes

Lawrence L Tankersley

Ronald D Esman

Irl N Duling, Iii

Douglas H Blackburn

David C Cranmer

Dale A Kauffman

Joseph E Landry

An optical device includes a polarization section having a port, the polarization section being for receiving light at the port and for outputting light at the port with a state of polarization orthoconjugate to the light received at the port. The polarization section includes a reflector, a bidirectional nonreciprocal rotator and a bidirectional polarizer. The bidirectional nonreciprocal rotator has first and second ends, the first end being operatively coupled to the port. The bidirectional polarizer has first and second ends, the first polarizer end being operatively coupled to the reflector and the second polarizer end being operatively coupled to the second rotator end. The optical device further includes an amplifying section having a port and a rotator-reflector, the amplifying section being for receiving light at the amplifying section port and for outputting light at the amplifying section port with a state of polarization orthoconjugate to the light received at the amplifying section port and being amplified with respect thereto. The optical device includes means for transmitting light in both directions between the polarization section port and the amplifying section port, and means responsive to light internal to the polarization section for outputting coherent light having a stable and known state of polarization.

Polarization-stable laser

A Faraday rotator glass composition based on a fluoride glass, phosphate glass, fluorophosphate glass or a mixture thereof is doped with a lanthanide in a concentration sufficient to provide a Verdet constant above at least 2870 deg/Tesla-meter [(1 min/cm-Oe).times.(1.667.times.10.sup.4)=1 deg/Tesla-meter] and optical transmission above at least 50 percent in a 25 mm thick polished glass sample at least at one wavelength in the 200 to 400 nm wavelength region. The Faraday rotator glass also includes monovalent non-lanthanide cations such as Na, Li, K or mixtures thereof in a concentration sufficient to provide a Verdet constant above at least 2870 deg/Tesla-meter and optical transmission above at least 50 percent in a 25 mm thick polished glass sample at least at one wavelength in the 200 to 400 nm wavelength region. The Faraday rotator glass further includes a concentration of divalent or trivalent non-lanthanide cations such as Mg, Be, Ca, Al or mixtures thereof sufficient to provide surface flatness of at least 1/10 of the operating wavelength at 632.8 nm.

Ultraviolet Faraday rotator glass

An unstable resonator laser cavity providing high power radiation with diaction-limited divergence and narrow-bandwidth comprises a gain medium for generating and amplifying laser radiation optically coupled to a reflector via a frequency narrowing element for providing feedback and bandwidth-narrowing of the laser radiation travelling between the gain medium and the reflector. A telescopic ring is optically coupled to the gain medium opposing the reflector. The telescopic ring comprises a polarized beam splitter, which transmits a first polarization polarized laser radiation into the telescopic ring travelling in a first direction and reflects a second polarization polarized laser radiation into the telescopic ring travelling in a second direction; first and second rotators for rotating the first polarization polarized laser radiation to provide second polarization polarized laser radiation travelling in the first direction; and lenses for magnifying the second polarization polarized laser radiation travelling in the first direction onto the polarized beam splitter, which reflects the second polarization polarized laser radiation produced by the first and second rotators back into the gain medium. A scraper mirror, located between the gain medium and the reflector, provides the output beam.

Narrow-bandwidth unstable resonator laser cavity

An ultraviolet optical isolater which utilizes a KDP-isomorph crystal as optical element is disclosed. In a preferred embodiment, the ultraviolet optical isolator comprises: an input polarizer for linearly polrizing an input beam of ultraviolet light in a first plane of polarization; means for rotating the plane of polarization of the linarly polarized ultraviolet light from the input polarizer by substantially 45 degrees in a first direction; a Faraday rotator including an optical element made of a KDP-isomorph crystal in which the plane of polarization of the rotated linearly polarized ultraviolet light from the rotating means is rotated about an optical axis of the optical element, a plurality of permanent magnets sequentially coupled together with altnerating polarities for developing a magnetic field along the optical axis of the optical element in order to cause the optical element to rotate the plane of polarization of the rotated linearly polarized ultraviolet light from the rotating means by substantially another 45 degrees in the first direction to a second plane of polarization substantially orthogonal to the first plane of polarization, and means for moving the optical element so that the optical element is always enclosed by the plurality of permanent magnets; and an output polarizer for outputting the ultraviolet light in the second plane of polarization.

Ultraviolet optical isolator utilizing the KDP-isomorphs

A laser cavity providing high power laser radiation with diffraction-limi divergence and narrow-bandwidth comprises: a stable laser cavity including a gain medium, which generates and amplifies laser radiation, optically coupled to first and second reflectors and an optical coupler; and an unstable laser cavity including the gain medium, the first reflector, the optical coupler and a scraper mirror. The scraper mirror is located between the gain medium and the optical coupler for producing an output beam. The stable laser cavity is restricted to operate on a low order TEM mode by an aperture located between the optical coupler and the second reflector. A frequency narrowing element located between the optical coupler and the second reflector narrows the bandwidth of the laser radiation in the stable laser cavity. The optical coupler couples the narrow bandwidth laser radiation from the stable laser cavity to the unstable laser cavity, thereby producing narrow bandwidth laser radiation in the output beam.

Narrow-bandwidth diffraction-limited coupled stable-unstable resonator

A narrow-bandwidth, unstable laser resonator comprising: an output section ncluding a laser gain medium for generating and amplifying light, a first reflective element for reflecting and collimating light from the gain medium back through the gain medium, and a second reflective element having a hole therein, the second reflective element being responsive to the collimated light passed through the gain medium for reflecting most of the collimated light out of the unstable laser resonator as an output beam and for passing the remaining portion of the collimated light through the hole therein as a residual beam; and a feedback ring including an optical path, a beam splitter for passing a first portion of the residual beam into the optical path in a first direction, a frequency-narrowing element disposed at a position in the optical path where the first portion of the residual beam is collimated, the frequency-narrowing element being operative to narrow the frequency bandwidth of the first portion of the residual beam to produce a narrow-bandwidth collimated beam, a lens disposed in the optical path for focusing the narrow-bandwidth collimated beam to cause light from that beam to be reflected from the beam splitter and passed through the hole in the second reflective element as a narrow-bandwidth convergent beam before the narrow-bandwidth convergent beam before the narrow-bandwidth convergent beam is amplified by the gain medium.

Growing community of inventors

Riva, MD, United States of America

David G Cooper