Lightwave Electronics Corporation

Chromatix, Inc.

Lightwave Electronics Co.

Lighthouse Electronics Corporation

Richard W Wallace

William M Grossman

Jason I Alexander

David C Shannon

Walter R Bosenberg

Leonard P Pearson

Thomas James Kane

David G Scerbak

John A Dutcher

Martin A Gifford

David C Gerstenberger

Daniel J Dere

Robert L Mortensen

Kurt J Weingarten

A non-linear optical device in which quasi-phase matching between different optical waves of differing polarizations and refractive indices increases the interaction length between the waves. The quasi-phase matching structure includes a periodic structure over which the non-linear coefficient varies with a given period, preferably the sign of the non-linear coefficient being inverted between two alternating regions. In LiNbO.sub.3, the periodic structure can be achieved by electrical poling. The required period length is increased by selecting light waves of different polarizations for the non-linear interaction such that a large portion of the dispersion between the waves of different wavelength is compensated by the birefringence of the waves of different polarization. In particular, periodic poling can quasi-phase match radiation in the range of 0.80 .mu.m to 1.2 .mu.m to generate second harmonic generation radiation in the blue and green visible spectrum.

Light generating device and method using a periodically structured

A laser system in which an intense laser beam of a predefined pumping wavelength traverses a non-linear material, such as crystalline lithium niobate, that has been impressed with one or more quasi phase matching (QPM) gratings is disclosed. Quasi phase matching compensates for the dispersion or birefringence in a non-linear material by modulating the non-linearity with the proper period such that the different wavelengths involved in the non-linear process stay in phase over a long interaction length. The first QPM grating promotes the parametric generation of a resonant signal whose wavelength is determined by the grating period. According to the invention, either a second QPM grating impressed in the same medium or a different order of the first QPM grating promotes the non-linear interaction between the resonant signal and another optical signal traversing the non-linear material. The multi-step process allows efficient generation of high power radiation in wavelength regions, such as the blue, or red, not easily accessible otherwise.

Multi quasi phase matched interactions in a non-linear crystal and

Multi quasi phase matched interactions in a non-linear crystal

Apparatus for end-pumping of a solid-state laser with a source of high optical brightness. A stack of diode laser bars are excited, and each bar emits a light beam of a selected pump wavelength in a chosen direction. The light beam output of the diode bar stack is divided into a plurality of smaller, approximately rectangular light beams, which serve as extended light sources, by a plurality of mirrors that are positioned to receive one or more of these smaller beams and redirect such beams onto first, light-receiving ends of one or more optical fibers. Light collection optics receive the beams issuing from the mirrors and focus these beams onto a light-receiving end of an optical fiber with beam convergence angles that are appropriate for the numerical aperture of that fiber. Second ends of the optical fibers are optionally positioned so that a light beam emitted from the second end of a fiber is received by a laser gain material in a laser cavity and propagates along a common optical path within the laser cavity, thereby pumping the laser gain material.

Multiple diode laser stack for pumping a solid-state laser

Apparatus for providing a laser light beam or an amplifier light beam that is scalable to very high light beam output power by use of approximately identical optical sections, each section containing one or more laser gain media and one or more fold mirrors, spaced apart from the laser gain media by a distance d. The laser gain media or the fold mirrors, or both, have a curved reflecting surface of radius R. The lengths d and R are chosen to provide a stable optical system within each optical section and to compensate for the development of a thermal lens within each laser gain medium when this medium is pumped by a light source. The optical sections may be concatenated to scale the light beam output power upward without limitation, except for optical absorption and losses that occur at each reflecting surface.

High power optical cavity for end-pumped solid state laser

A miniature laser cavity in which a solid-state lasing gain element and a Q-switch have respective end surfaces at substantially the Brewster angle, parallel to and facing each other, and separated by a narrow gap occupied by a transparent low-index-of-refraction material.

Laser with Brewster angled-surface Q-switch alinged co-axially

A diode pumped solid-state laser is disclosed having: a block of a lasing gain material with at least two optical surfaces and a cavity means positioned around the block to define a laser cavity which includes a mode shaping means to form an eliptical resonator mode between the optical faces within the block; a high aspect ratio pumping laser diode light source is positioned outside one of said optical faces; and a means to image the pumping light beam from said source to substantially match the elliptical resonator mode.

Elliptical mode cavities for solid-state lasers pumped by laser diodes

A diode imaging system using a single objective lens and a single cylindrical lens. This imaging system does not image perfectly point-to-point, and although not an apparent extension of imaging systems known in the prior art, it works advantageously for imaging beams from diode lasers having long narrow junctions used in pumping solid-state lasers.

Laser diode light imaging optics

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

An optical Faraday isolator includes a slab of Faraday rotator medium coated to define input and output faces and internal reflective surfaces for causing the beam to travel between the input and output faces along a zig-zag path. Permanent magnets polarized in a direction normal to the plane defined by the zig-zag beam path are disposed on opposite sides of the beam path. The magnets are paired on each side with serially alternating polarity and the like poles are in transverse registration on opposite sides of the beam path to produce an intense, unidirectional magnetic field parallel to the beam path within the rotator slab. A quarterwave plate introduces a compensating amount of elliptical polarization to cancel unwanted elliptical polarization effects of the slab and its coatings. A beam shaving aperture at the exit of the slab shaves off divergent backward travelling rays.

Optical isolator employing multipass faraday rotation

A laser photometer including means forming an unsupported curtain of liquid sample, means for focusing a laser beam at a sample volume in the unsupported liquid curtain, means for receiving a cone of light issuing from the sample in an incremental angle .DELTA..theta. at an angle .theta., means for focusing the cone of light at a field stop and a detector for receiving the power passing through the aperture.

Light scattering photometer and sample handling system therefor

An optical cavity for a flash lamp pumped dye laser including a pumping cavity, a birefringent filter and a plurality of frequency doubling crystals. Within the pumping cavity the flash lamp is cooled by forced air convection and operated with a D.C. simmer current. Simultaneously, the dye carrying conduit within the pumping cavity is cooled with water. The operating life of the dye is increased by using selectable filters to remove the ultraviolet radiation eminating from the flash lamp before it falls on the dye. The construction of the pumping cavity permits changing the flash lamp and the dye conduit without disturbing the optical path of the laser.

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Los Altos, CA, United States of America

Richard W Wallace