Samuel S M Lu

US Patent:

54575702, Oct 10, 1995

Filed:

May 25, 1993

Appl. No.:

8/067863

Inventors:

Samuel Lu - Agoura CA
Alan F. Stewart - Thousand Oaks CA
Anthony W. Louderback - Eugene OR

Assignee:

Litton Systems, Inc. - Beverly Hills CA

International Classification:

G02B 520

US Classification:

359361

Abstract:

A coating for an optical component is formed to be antireflective for a selected wavelength and resistive to the transmission of ultraviolet radiation. The coating has first layer is formed of a dielectric material having a refractive index n. sub. 1 coated onto the optical component. A second layer is formed of a dielectric layer having a refractive index n. sub. 2 that is smaller than the refractive index n. sub. 1 of the first layer. The second layer is formed of a material that transmits the selected wavelength while blocking ultraviolet light, thereby protecting the first layer and the optical component from damage due to exposure to ultraviolet radiation. The thicknesses of the layers is selected so that the coating is antireflective for the selected wavelength.

US Patent:

49040839, Feb 27, 1990

Filed:

Mar 10, 1989

Appl. No.:

7/320786

Inventors:

Samuel Lu - Moorpark CA
Kevin D. Grobsky - Canyon Country CA

Assignee:

Litton Systems, Inc. - Woodland Hills CA

International Classification:

G01C 1964

US Classification:

356350

Abstract:

Provided herein is a ring laser gyro system having a special and improved partially transparent output mirror which provides relatively undistorted circularly polarized coherent light beams to the photo detector and amplifier of the system from the laser cavity thereof. This improved mirror achieves its results by sandwiching a non-quarterwave stack between two quarterwave stacks of multi layer, all of which are coated on a Zerodur substate mirror. The improved mirror achieves nearly Zero phase retardation and a Tp/Ts ratio equal to one.

US Patent:

55130399, Apr 30, 1996

Filed:

May 26, 1993

Appl. No.:

8/067385

Inventors:

Samuel Lu - Agoura CA
Alan F. Stewart - Thousand Oaks CA
Anthony W. Louderback - Eugene OR

Assignee:

Litton Systems, Inc. - Woodland Hills CA

International Classification:

G02B 110

US Classification:

359584

Abstract:

A mirror for reflecting a selected frequency of light includes a plurality of alternating quarter wavelength thick layers of two dielectric materials that are resistive to physical and chemical changes upon exposure to ultraviolet radiation coated upon a substrate. The materials have different refractive indices. The materials preferably are comprised of a mixture of alumina and tantala as the high refractive index layer and alumina as the low refractive index layer.