Coherent, Inc.

Bruce E Perilloux

Dennis G Fischer

Thomas F Johnston, Jr

Mark H Lange

Arnold L Bloom

Larry Giammona

Stephen D Vincent

Charles K Langhorn

A filter system for reflectively blocking laser radiation in the visible spectrum includes a multilayer interference structure arranged for reflectively blocking a continuous band of wavelengths including the laser radiation and transmitting other wavelengths in the visible spectrum. The filter system is arranged to control transmission of the other wavelengths of the visible spectrum such that the filter system has an essentially neutral transmission color and maximum photopic transmission consistent with the band of wavelengths reflectively blocked.

Laser blocking filter with neutral transmission color

A laser 10 is disclosed in which there are incorporated one or more diffractive optical elements (DOE's) 20. The DOE's can be used in place of conventional optics to save costs and allow design of resonators not heretofore possible. The ability to vary the reflectivity of the surface of a DOE in any desired pattern allows unprecedented control of both the intracavity mode as well as the mode of the output beam.

Laser resonators employing diffractive optical elements

A short-wave-pass optical filter, including a partially absorbing or transparent substrate coated by a set of layers having different quarter-wave optical thicknesses, which is designed to reflect visible radiation of a selected color white transmitting visible radiation and maintaining a neutral color balance. The inventive filter is designed so that the desired reflected color (and the transmitted neutral color balance) is substantially independent of viewing angle (i.e., the incidence angle). In a preferred embodiment, the substrate is composed of UV-absorbing glass, and the coating is substantially a double quarter-wave stack of alternating layers of SiO.sub.2 and TiO.sub.2, TiO or Ti.sub.2 O.sub.3. The reflectance of the inventive filter (as a function of wavelength) is designed to have a ripple in at least one segment of the visible spectrum, but to have no significant ripples in all other segments of the visible spectrum. The partial reflection represented by the one or more rippled regions is sufficient to give the filter a desired aesthetic color, such as violet, orange, or blue. In a preferred embodiment, the visible light reflected by the inventive filter corresponds not only to a first rippled region, but also to a second rippled region or 'partial second-order stopband' (or both), where each rippled region and partial second-order stopband is positioned so that, as the reflected light is viewed with changing incidence angle, the reflected color will not significantly change.

Chromatically invariant multilayer dielectric thin film coating

A short-wave-pass optical filter, that includes a partially absorbing or transparent substrate coated by a set of layers having specified quarter-wave optical thickness, and is designed to reflect visible radiation of a selected color while transmitting visible radiation and maintaining a neutral color balance. The coating includes layers having a high refractive index alternating with layers having a low refractive index. The refractive indices and layer thicknesses are selected so that the filter's reflectance spectrum exhibits a ripple over a first segment of the visible spectrum but no significant ripple over a second segment of the visible. The filters may be used as sunglass lenses that have a selected color (such as blue, orange, or violet) when viewed by one other than the sunglass wearer, while permitting the wearer to perceive transmitted light with a correct color balance. The design of the inventive filter is preferably optimized to have the desired optical properties while being conveniently and repeatably manufacturable.

Multilayer optical filter for producing colored reflected light and

A polarization preserving reflector for reflecting an incident beam of monochromatic radiation, said beam having a polarization configuration and an angle of incidence. The polarization preserving reflector comprises a substrate; a highly reflective layer positioned adjacent to said substrate; and at least two thin film optical layers one of which being positioned adjacent to the highly reflective layer, one of the thin film optical layers having a high refractive index and another having a low refractive index, for maintaining the incident polarization configuration while producing a high reflectance upon reflection of the beam therefrom in a wide range of the angle of incidence from approximately zero degrees to 75 degrees.

Growing community of inventors

Grass Valley, CA, United States of America

Bruce E Perilloux