POLARIZATION DYNAMICS OF STRAINED 1.3 MU-M INGAASP-INP LASERS - SPECTRAL PROPERTIES AND LATERAL NEAR-FIELD BEHAVIOR

Emission from a tensile-strained ridge-waveguide InGaAsP-InP laser, wh ich exhibits a transition between TE and TM polarization when the DC i njection current exceeds a certain value, was investigated by lime-and polarization-resolved measurements. Under excitation with 100 ps curr ent pulses the laser emits pairs of TE and TM pulses of about 50 ps du ration. The longitudinal modes of the emission spectrum exhibit differ ent spectral profiles depending on the mode wavelength, which can be e xplained in terms of the mode competition and asymmetric gain dispersi on. The near-field intensity distribution of the laser excited with a 1.4 ns current pulse shows periodic changes of its lateral width assoc iated with 3 GHz relaxation oscillations alternating between TE and TM polarization.