At&t Bell Laboratories

Bell Telephone Laboratories

American Telephone & Telegraph Co., At&t Bell Laboratories

Cornell Research Foundation Inc.

Thomas J Bridges

Ernest G Burkhardt

Larry Allen Coldren

Thomas L Koch

Albert R Strnad

Obert R Wood, Ii

Chinlon Lin

Gerardo Beni

Chandra K Patel

Susan Hackwood

David B Karlin

Epitaxial regrowth by vapor phase epitaxy of controlled composition semiconductor material in and around undercut regions of a processed heterostructure wafer permits formation of a ridge waveguide capable of active or passive operation. Subsequent material selective and crystallographically preferential etching is employed to form mirror facets on each end of the ridge waveguide.

Buried undercut mesa-like waveguide and method of making same

Buried undercut mesa-like waveguide

Articulated arm for guiding infrared radiation, with preferred wavelength between about 1 .mu.m and about 100 .mu.m, from a typically stationary radiation source to a moving or movable target. The inventive arm comprises hollow waveguides of the Marcatili-Schmeltzer type, with preferred bore diameter between about 50 and about 200 wavelengths of the radiation to be guided in the bore. Preferred waveguides consist of glass or quartz tubes of cylindrical cross section. The waveguides are typically held coaxially inside straight tubular members, the members being connected movably in end-to-end fashion. Beam direction altering means, for instance, reflecting means such as plane mirrors, serve to direct the radiation from the output end of one waveguide into the input end of the next waveguide. The articulated arm according to the invention typically is mode preserving, e.g., single mode radiation remains single mode, has high pointing accuracy, i.e., the direction of the output beam is substantially constant with respect to the axis of the output segment of the arm regardless of the spatial position or configuration of the arm. The arm can be designed to be mechanically light and higly maneuverable, and can be used in conjunction with a variety of output devices or probes. An exemplary probe useful, e.g., in transvitreal coagulation of retinal vessels, comprises hollow dielectric waveguides, including a tapered waveguide section. In addition to use in eye surgery and other surgical procedures, the inventive arm can advantageously be applied in such industrial processes as welding, soldering, cutting, annealing, scribing, drilling, and resistor trimming with infrared radiation.

Apparatus comprising an articulated arm radiation guide

A laser surgical instrument uses a CO.sub.2 laser source and an articulated arm structure to maintain single mode transmission of a 10.6 .mu.m beam to probe. In one configuration, high power is maintained for photo-transection and/or photocauterization. A second probe embodiment introduces other degrees of functionality such as aspiration, irrigation and internal viewing. Internal illumination is achieved by using the sheaths of quartz waveguides to transmit visible light while the laser beam is propagated internally in the waveguide structure.

Laser surgical system

An articulating waveguide arm assembly, comprising long arm segments, (11, 12, 15, 17, 19) and short corner segments (13, 14, 16, 18) has a single-mode hollow dielectric waveguide located inside each segment and an optically reflecting device (33, 34, 37, 38, 39) located at the end of each segment. The waveguide assembly is mechanically affixed to a robot assembly having protruding side shields (65, 66). The robot assembly includes a pair of long arms (61, 62) corresponding to a pair of the waveguide arms (15, 17). Another waveguide arm segment (12) of the waveguide assembly passes over the protruding side shields and terminates in a pair of successive corner segments (13, 14) for enabling a laser beam propagating through this long arm segment to enter into one of the pair of long waveguide segments (61). The robot arm segments control the orientation of corresponding articulating waveguide arm segments, whereby a laser beam entering the articulating waveguide arm assembly will exit from the waveguide assembly positioned and oriented as determined by the positions and orientations of the robot arm segments.

Waveguide robot system for laser beam

The present invention relates to an apparatus for laser isotope detection and concentration measurement (LIDAM). A test sample containing first and second isotopes of a specific material or compounds formed with the first and second isotopes of the specific material is placed in an optical bridge with a standard sample containing known amounts of the first and second isotopes or compounds of the same. Laser radiation from a first and a second laser source is alternatively focused upon the two samples to produce fluorescence from the isotopes or compounds of the specific material. The laser material of the first laser source and the laser material of the second laser source are either the first and the second isotope respectively or compounds formed with the first and the second isotope respectively. Laser radiation from the first and the second laser source induces fluorescence only from the first and second isotope or compounds of the same in either the test or standard sample. The characteristic fluorescences induced are detected and used to determine the relative ratios of the first and second isotopes or compounds of the same in the test sample.

Laser isotope detection and measurement

The spectrophone, in which a gas containing an impurity in an absorption cell is illuminated by an optical beam that is modulated at an acoustic frequency, has an output pressure response at the acoustic frequency in accordance with the concentration of the impurity in the gas. This output is tuned by a magnetic (or electric) field applied to the absorption cell, while the optical wavelength is kept constant. The Zeeman (or Stark) effect of the impurity can thus be used to tune the absorption process of the impurity to a maximum response.

Growing community of inventors

Holmdel, NJ, United States of America

Thomas J Bridges