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HL: Halbleiterphysik

HL 3: Halbleiterlaser I

HL 3.5: Vortrag

Montag, 24. März 2003, 11:30–11:45, BEY/81

Highspeed Modulation Properties of Segmented Contact Semiconductor Lasers — •Nicoleta Azap, Edeltraud Gehrig, and Ortwin Hess — Theoretical Quantum Electronics, DLR, Pfaffenwaldring 38-40, D-70569 Stuttgart

The highspeed-modulation dynamics of semiconductor lasers is determined by a complex interplay of ultrafast light-field and carrier dynamics. The characteristic times-scales of the underlying physical processes determine the relaxation oscillations and set an upper limit to the modulation of a single-mode semiconductor laser. In spatially extended semiconductor lasers,however, numerous longitudinal and transverse modes coexist. An excitation of a high harmonic beat frequency associated with these modes should consequently enable a high-frequency modulation of the laser. We present results of simulations on the modulation characteristics of twin-stripe semiconductor lasers on the basis of multi-mode Maxwell Bloch equations that include propagation effects and spatio-temporally varying mode competition. Our simulations reveal that a suitable design of contact segmentation and resonator geometry allows to directly influence the lateral coupling and transverse mode dynamics of a given laser structure, eventually allowing high speed modulation of the laser beyond its usual limits.