Wavelength-stabilized, high power semiconductor laser

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United States Patent im

Mehuys et al.

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US005537432A [11] Patent Number: [45] Date of Patent:

5,537,432 Jul. 16, 1996

[54] WAVELENGTH-STABILIZED, HIGH POWER SEMICONDUCTOR LASER

[75] Inventors: David G. Mehuys, Sunnyvale; David F. Welch, Menlo Park; Robert J. Lang, Pleasanton; Donald R. Scifres, San

Jose, all of Calif.

[73] Assignee: SDL, Inc., San Jose, Calif.

[21] Appl. No.: 390,121

[22] Filed: Feb. 17, 1995

Related U.S. Application Data

[63] Continuation-in-part of Ser. No. 1,735, Jan. 7,1993, Pat. No. 5,392,308.

[51] Int. CI.6 HOIS 3/19

[52] U.S. CI 372/50; 372/32; 372/46;

372/94; 372/96; 372/99; 372/102

[58] Field of Search 372/44-50, 97,

372/99, 100, 101, 102, 94, 96, 29, 32

[56] References Cited

U.S. PATENT DOCUMENTS

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OTHER PUBLICATIONS

Sorin et al., "Single-frequency output from a broadband-tunable external fiber-cavity laser," Optics Letters, vol. 13, No. 9, Sep. 1988.

Zorabedian et al., "Interference-filter-tuned, alignment-stabilized, semiconductor external-cavity laser," Optics Letters, vol. 13, No. 10, pp. 826-828, Oct. 1988.

(List continued on next page.)

Primary Examiner—Rodney B. Bovernick
Assistant Examiner—Hemang Sanghavi
Attorney, Agent, or Firm—Schneck & McHugh

A wavelength-stabilized, semiconductor laser having a light amplifying diode heterostructure with a flared gain region in an external resonant cavity. The flared gain region has a narrow aperture end which may be coupled to a single mode waveguide and a wide output end. A light emitting surface of the heterostructure proximate to the wide end of the flared gain region is partially reflective and combines with an external reflector to form a resonant cavity that is effectively unstable. The intracavity light-emitting surface proximate to the narrow aperture end is antireflection coated. The external reflector may be a planar mirror or a grating reflector. A lens or an optical fiber may couple the aperture end of the flared gain region to the external reflector. Frequency-selective feedback is provided by orienting the grating reflector or providing a prism in the cavity in front of the external planar mirror. Other filtering elements may also be placed in the external cavity. The flared gain region and waveguide may be differentially pumped or modulated with current provided by separate contacts.

105 Claims, 11 Drawing Sheets

OTHER PUBLICATIONS

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