DEGRADATION OF MICROGUN-PUMPED BLUE LASERS

Microgun-pumped blue lasers with lasing thresholds in the 4-20 kW/cm(2 ) range for temperatures between 83 and 225 K were fabricated by molec ular beam epitaxy. The devices exploit graded index, separate confinem ent Zn1-xCdxSe/ZnSe heterostructures and use an array of low-voltage f ield-emission microtips for electron beam pumping. Degradation occurs through the formation of characteristic (100) dark-line defects, as in diode lasers. The device lifetime exceeded several hours at 83 K for a laser operating at 478.4 nm with a 12.5% duty-cycle.