Accession Number : ADP008114

Title :   Spatial Soliton in a Self-Focusing Semiconductor Gain Medium,

Corporate Author : NIPPON TELEGRAPH AND TELEPHONE CORP IBARAKI OPTO-ELECTRONIC LABS

Personal Author(s) : Khitrova, G. ; Gibbs, H. M. ; Kawamura, Y. ; Iwamura, H. ; Ikegami, T.

Report Date : APR 1992

Pagination or Media Count : 2

Abstract : The pulse broadening by group velocity dispersion can be balanced by the narrowing effect of self-phase modulation to form temporal solitons. The identical nonlinear Schrodinger equation describes the one-transverse-dimension balancing of diffraction and Kerr-medium nonlinear refraction. Some evidence for spatial solitons has been published for planar waveguides of CS2 and glass, both in Kerr (n2) media. Here we report soliton formation in a semiconductor gain medium which is amplifying rather than lossy, is accumulative rather than instantaneous, and is near resonance instead of far from resonance. The self-focusing semiconductor gain medium is obtained by current injection into the following planar waveguide structure. A crystal was grown by gas-source molecular beam epitaxy on an n-doped InP substrate: 1.0-micrometer-thick n-doped InP buffer; 0.6-micrometer-thick guiding layer consisting of n-doped In0.78Ga0.22AS0AS.55P0.45 and six 42-A Ga0.47In0.53 As/30-A Al0.48In0.52As quantum wells in the center, p-doped In0.78Ga0.22As0.55P 0.45; 2 micrometer of p-doped InP; and 0.1 micrometer of p-doped Ga0.47 In 0.53 As contact layer. Photolithography and chemical etching were used to leave 80-micrometer-wide strips. This structure lases at = 1.31 micrometer with a threshold current of 1.2 A for a length of 400 micrometer.

Descriptors :   *GAIN, *SEMICONDUCTORS, *SYMPOSIA, BUFFERS, CRYSTALS, DIFFRACTION, DISPERSIONS, FOCUSING, GROUP VELOCITY, MOLECULAR BEAMS, PHASE MODULATION, PHOTOLITHOGRAPHY, PULSES, REFRACTION, SCHRODINGER EQUATION, SOLITONS, STRUCTURES, SUBSTRATES, WAVEGUIDES, EPITAXIAL GROWTH, INDIUM PHOSPHIDES, KERR CELLS, OPTICAL WAVEGUIDES, LIGHT MODULATORS, JAPAN.

Subject Categories : Fiber Optics and Integrated Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE