Bell Telephone Laboratories

Amoco Corporation

At&t Bell Laboratories

Leo F Johnson

Legrand G Van Uitert

Shobha Singh

Robert J Thrash

Douglas W Anthon

John H Clark

Dawon Kahng

Timothy J Pier

An upconversion laser system that uses solid state components throughout and achieves such operation with a substantially coherent, continuous or quasi-continuous single band infrared pumping source using successive energy transfers between the sensitizer and activator in the host of the lasant upconversion material.

Rare earth ion upconversion laser system

An upconversion laser system that uses solid state components throughout and achieves such operation with a continuous or quasi-continuous single band infrared pumping source using successive energy transfers between the sensitizer and activator in the host of the lasant upconversion material.

A laser apparatus and method is disclosed comprising a first lasant material which is located in an optical cavity and which produces laser radiation of a first wavelength, and a second lasant material which is pumped by radiation from the first lasant material, which absorbs laser radiation at the first wavelength in an amount generally comparable to the Optimum Output Coupling, which functions as the output coupler for the optical cavity and which lases at a second wavelength. The first lasant material and the second lasant material are preferably selected to have minimal losses such that there is a net gain in the cavity.

Apparatus and method for pumping of a weakly absorbing lasant material

A method of planarizing a surface using ion beam milling at a non-normal angle of incidence that is useful in semiconductor device manufacture is described.

Method for planarizing patterned surfaces

Optical communications networks may be implemented by means of a patterned layer of an optically transparent material on a substrate. Where an optical path terminates, e.g., at an on-off switch, it is desirable to optically terminate a waveguide so as to minimize spurious signals due to reflection. The invention provides for optical termination of a waveguide by essentially complete absorption of light. Absorption is effected in a portion of the waveguide which comprises light absorbing centers such as, e.g., carbon or metal particles, anions, cations, or molecules which absorb light at desired wavelengths. Absorbing centers may be comprised in a central portion of a waveguide or, more conveniently, in a portion adjacent to a central portion. In the interest of minimizing reflections, interaction between light and absorbing centers increases gradually in a direction of light propagation as may be due to gradually increasing concentration of absorbing centers or to taper in a waveguide cladding portion, core portion, or absorbing portion.

Optical waveguide termination

A method is described for increasing the spatial frequency of surface relief structures. Periods as small as 750 Angstroms have been made.

Surface gratings and a method of increasing their spatial frequency

Electrically activated components such as switches, modulators, attenuators, and mode selectors are disclosed which can be used in networks of waveguides in optical communications systems. Disclosed components comprise an electrochromic medium in combination with a suitable ion source and means for producing a variable electric field across the medium. A change of color in the medium in response to variation of the electric field strength is instrumental in influencing direction and intensity of light propagating in a network.

Electrochromic optical device

Electrically activated optical switches, couplers, and modulators are disclosed which can be incorporated in waveguide networks in optical communications systems. Disclosed devices comprise an electroplating medium in combination with a suitable source of an electric field whose strength can be varied to cause transition of the electroplating medium between plated and unplated states. Changes of reflectivity and refractive index are the bases of switching and coupling applications, respectively.

Electro-optical device based on electroplating action

An oblique shadow deposition technique for altering the profile of grating relief patterns on surfaces is described. In one aspect the technique essentially represents a method whereby a series of grating masks may be superimposed in precise registration with each other. By appropriate choice of deposition angle, deep grooves may be generated from shallow profiles, rounded or sinusoidal profiles may be transformed to structures with planar vertical walls, and symmetric profiles may be made asymmetric.

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Bedminster, NJ, United States of America

Leo F Johnson