Laser diode device having a substantially circular light output beam and a ...

United States Patent [w]

Jeon et al.

[54] LASER DIODE DEVICE HAVING A SUBSTANTIALLY CIRCULAR LIGHT OUTPUT BEAM AND A METHOD OF FORMING A TAPERED SECTION IN A SEMICONDUCTOR DEVICE TO PROVIDE FOR A REPRODUCIBLE MODE PROFILE OF THE OUTPUT BEAM

[75] Inventors: Heonsu Jeon; Jean-Marc Verdiell,

both of Palo Alto, Calif.

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

[21] Appl. No.: 08/985,820 [22] Filed: Dec. 5, 1997

[51] Int. CI.7 HOIS 3/085

[52] U.S. CI 372/46; 372/45; 372/50

[58] Field of Search 372/45, 50, 46;

385/28, 43, 49

[56] References Cited

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5.844,929 12/1998 Lealman et al 372/45

5.930,423 7/1999 Chen et al 385/49

5,937,120 8/1999 Higashi 385/49

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US006052397A [ii] Patent Number: 6,052,397 [45] Date of Patent: Apr. 18,2000

5,987,046 11/1999 Kobayashi et al 372/45

OTHER PUBLICATIONS

T. Brenner et al., "Vertically Tapered InGaAsp/InP Waveguides for Highly Efficient Coupling to Flat-End Single-Mode Fibers", Applied Physics Letters, vol. 65(7), pp. 798-800, Aug. 15, 1994.

T. Brenner et al., "Compact InGaAsp/InP Laser Diodes with Integrated Mode Expander for Efficient Coupling to flat-Ended Single Mode Fibres", Electronics Letters, vol. 31(17), pp. 1443-1445, Aug. 17, 1995. T. Brenner et al., "Integrated Optical Modeshape Adapters in InGaAsP/InP for Efficient Fiber-to-Waveguide Coupling," IEEE Photonics Technology Letters, vol. 5, No. 9, 1053-1056 (Sep., 1993).

Primary Examiner—-James W. Davie

Attorney, Agent, or Firm—-W. Douglas Carothers, Jr.

[57] ABSTRACT

A device and method for fabricating a high power laser diode device with an output emission with a nearly circular mode profile for efficient coupling into an optical fiber. A vertical taper waveguide and a window tolerance region are formed in a base structure of the device employing successive etching steps. Further regowth completes the device structure. The resultant laser device has a vertical and lateral tapered waveguide that adiabatically transforms the highly elliptical mode profile in an active gain section of the device into a substantially circular mode profile in a passive waveguide section of the device.

14 Claims, 10 Drawing Sheets