Evanescent field profiles of whispering gallery ~WG! modes in a 1.6-mm-GaInAsP microdisk injection laser were investigated by scanning a nanoprobe near the periphery of a lasing microdisk. The increase in threshold current due to the light scattering by the probe and the corresponding decrease in laser light were observed experimentally. Two-dimensional images of the evanescent field, which agr...

The dynamical response of InAs/GaAs quantum-dot microdisk lasers has been experimentally investigated using femtosecond optical pumping. Because surface recombination and carrier diffusion are suppressed in the quantum dots, the response speed of a quantum-dot microdisk laser is much faster than that of a quantum-well microdisk laser. A turn-on time as short as 7.8 ps has been achieved in a qua...

Optically pumped InAs quantum dot microdisk lasers with grooves etched on their surface by a focused ion beam are studied. It is shown that the radial grooves, depending on their length, suppress the lasing of specific radial modes of the microdisk. Total suppression of all radial modes, except for the fundamental radial one, is also demonstrated. The comparison of laser spectra measured at 78 ...

We demonstrate that quantum dot microdisk lasers are able to operate under continuous wave current injection at 100 o C. We also present a novel method for increasing a side mode suppression ratio in microdisk lasers.

This report characterizes the whispering-gallery mode (WGM) resonators with the design of waveguide and microdisk coupling microstructure. In order to understand and optimize the design, studies over a broad range of resonator configuration parameters including the microdisk size, the gap separating the microdisk and waveguide, and the waveguide width are numerically conducted. The finite eleme...

Arial 10) It has been recently shown that the propagation direction of guided waves can be properly selected just by using as an excitation source a circularly-polarized dipole put in close proximity to a waveguide [1]. Although in Ref. [1] the concept was experimentally demonstrated for plasmonic waves (visible wavelengths), it can be extended to other kinds of waveguides and technological pla...

Coupled-microdisk photonic molecules with high-symmetry geometries that support nondegenerate whispering gallery modes with high quality factors are numerically designed, based on a two-dimensional model. Dramatic enhancement of calculated Q factors of nondegenerate modes as compared with single-microdisk whispering gallery modes of the same radial order is achieved by tuning the intercavity co...

Dynamic response of a GaAs/AlGaAs microdisk laser has been experimentally investigated using femtosecond optical pumping. Below the lasing threshold, the delay time of the emission pulse from the microdisk hardly changes with the pump power. Above the lasing threshold, the delay time is shortened dramatically, and it decreases with increasing the pump power. The theoretical simulation based on ...

Microdisk structures have been used to achieve low-threshold lasing. For these microcavity lasers, the spontaneous emission coupling factor p is an important parameter since it determines the threshold current of the laser. Theoretical calculation of p based on the exact solution of the modes in a microdisk is complicated. A simple, approximate method for solving the waveguide modes and the den...

We have utilized hybrid zinc oxide/silica microdisk lasers to sense volatile organic compounds, such as toluene and nitrobenzene. Nonspecific adsorption of these organic molecules onto the microdisk surface causes an increase in the disk refractive index, ultimately resulting in a redshift of the observed lasing wavelengths. The monitoring of these shifts provides the sensing modality. Microdis...