TE polarization of optical emission from microdisk laser diodes of radius R=5 μm, thickness L=0.3 μm, is found to dominate both below and above room-temperature lasing threshold current, Ith=2 mA. TE emission in the lasing mode at λ=1560 nm wavelength is due to higher optical gain for TE modes in the quantum well device. In our device geometry, the intrinsic whispering gallery resonances have essentially no polarization selectivity.

No abstract

We report the transient response of wavelength switching in multicavity laser diodes. Spatially separated Bragg gratings embedded in a single fiber are used to map optical emission wavelength to photon round-trip time in an external cavity mode-locked laser diode. Transient emission wavelength and mode-locked pulse formation are explored by switching applied radio frequency modulation. Initial conditions are found to dominate transient response. A hot photon cavity has a characteristic rise time corresponding to approximately two photon cavity round trips. A cold photon cavity exhibits significant turn-on delay and rise time that depends on applied radio frequency signal power and is independent of above threshold steady-state current bias.

Articles you may be interested inLittrow-type external-cavity diode laser with a triangular prism for suppression of the lateral shift of output beam Rev. Sci. Instrum. 77, 046102 (2006); 10.1063/1.2190287 Broad-area laser diode with 0.02 nm bandwidth and diffraction limited output due to double external cavity feedback Appl. Phys. Lett. 85, 525 (2004); 10.1063/1.1774248 Single-frequency external-cavity tapered diode laser in a double-ended cavity configuration Rev. Sci. Instrum. 71, 1 (2000)

By controlling optical loss in a multiple cavity laser, it is possible to sequentially switch the lasing wavelength with a mode suppression ratio greater than −35 dB. Our experiments use an antireflection coated semiconductor laser diode with optical feedback from Bragg gratings embedded in a single mode fiber. Residual reflectivity from the antireflection coating plays a critical role in determining device operation.