WHISPERING-GALLERY MODE MICRODISK LASERS

A new microlaser design based on the high-reflectivity whispering-gallery modes around the edge of a thin semiconductor microdisk is described and initial experimental results are presented. Optical confinement within the thin disk plane results in a microresonator with potential for single-mode, ultralow threshold lasers. Initial experiments use selective etching techniques in the InP/InGaAsP system to achieve 3-10-mu-m diameter disks as thin as 500 angstrom suspended in air or SiO2 on an InP pedestal. Optically pumped InGaAs quantum wells provide sufficient gain when cooled with liquid nitrogen to obtain single-mode lasing at 1.3 and 1.5-mu-m wavelengths with threshold pump powers below 100-mu-W.