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Title: Bistability in grating-tuned external-cavity semiconductor lasers

Journal Article · · IEEE J. Quant. Electron.; (United States)

Bistability has been observed in the tuning characteristic and power versus current radiation of a 1.3 ..mu..m grating-tuned external-cavity semiconductor laser. Tuning-direction reversal, current variations, and feedback interruption can change the output power and threshold current at a given wavelength. These effects are shown theoretically to be due to the coupling of the semiconductor gain and index of refraction. From measurements of the semiconductor chip facet reflectivity, solitary laser diode mode spectrum, and tuning curve in the presence of external feedback, the analysis yields values for the external feedback strength, semiconductor modal loss, and linewidth enhancement factor. Using an InGaAsP double-channel-planar-buried-heterostructure laser diode with a 4 percent reflectivity antireflection-coated facet inside an external cavity consisting of a 0.60 numerical aperture lens and a 1200 line/mm diffraction grating, the authors found 22 percent external feedback, 60 cm/sup -1/ model loss, and a linewidth enhancement factor ..cap alpha.. = -7.1.

Research Organization:
Hewlett-Packard Labs., Palo Alto, CA 94304
OSTI ID:
5612578
Journal Information:
IEEE J. Quant. Electron.; (United States), Vol. QE-23:11
Country of Publication:
United States
Language:
English