Trw Limited

Pco, Inc.

Bor-Uei Chen

Frank E Goodwin

Ching-Jong Lii

Dong-Chaung Jou

A single-mode optical fiber delay line for filtering at high frequencies utilizes an nth order cascaded recirculating configuration comprised of n+1 couplers. Each coupler has two input fibers and two output fibers. One of the output fibers of each coupler except the last is connected to one of the input fibers of the next coupler in cascade to form a feed-forward path. The other output fiber of each coupler except the first is connected to the other input fiber of the preceding coupler, thus forming a feed-backward path. The feed-forward path and the feed-backward path of adjacent couplers form a delay loop. The delay time in each succeeding delay loop is increased by an incremental delay .tau. equal to the reciprocal of the center frequency of the filter. The delay in the first delay loop is selected to be some multiple m of .tau., where m is an integer selected for a total delay T which permits the use of optical fiber of a length sufficient to avoid bending losses in the optical fiber. The incremental time delay .tau. can be made extremely small, thereby making the operating frequency of the filter extremely high.

Cascaded recirculating transmission line without bending loss limitations

A device for combining the outputs of multiple laser sources to produce a single coherent beam with good far-field characteristics. The device includes an optical star coupler having multiple path lengths that are deliberately chosen to be different, by amounts that give rise to an interference pattern that has constructive interference peaks at periodic cycles along a wavelength interval. The optical path-length differences result in the occurrence of at least one wavelength, within the operating range of the lasers, at which all of the lasers will operate. The relationships among the optical path lengths is such that the lasing wavelength is relatively insensitive to phase mismatches along the path lengths.

Laser combiner

A semiconductor laser device having an array of injection laser diodes with laser cavities coupled to respective inputs of an optical star coupler. The star coupler functions both as a power combiner, to provide a single high-power output, an as a device to couple the laser cavities into a single integrated lasing region, for improved coherence and divergence properties and practically no wavefront distortion.

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Studio City, CA, United States of America

Bor-Uei Chen