Russian researchers demonstrate blue-green, room-temperature VCSEL
Russian Nobel Laureates N. G. Basov and A. M. Prokhorov described a room-temperature electron-beam-pumped vertical-cavity surface-emitting laser (VCSEL) in CLEO `95 postdeadline paper CPD24. In the joint effort by the Lebedev Physical Institute and General Physics Institute (both in Moscow, Russia), a VCSEL was fabricated by growing a multiple-quantum-well superlattice structure (SLS) on a chromium-doped GaAs substrate made u¥of 150 periods of ZnCdSe wells and ZnSe barriers. Dielectric mirrors were deposited on the structure by alternating an SLS and ZnSe in quarter-wave layers. Excitation was via a CW electron beam with energies u¥to 40 keV scanning at 50 H¥to induce VCSEL action at 484 nm. Output beam diameter was 20 mm, beam divergence angle was within 10°, and peak output power was 1.6 W.
The Lebedev Institute has been working on electron-beam-pumped lasers (EBSLs) for projection displays for more than 20 years, believing they have the potential for better than 2000 scan lines resolution exceeding 5000-lm brightness. It developed room-temperature crystal lasers last year; the VCSEL demonstration is the next ste¥toward commercial applications. Principia Optics (Los Angeles, CA) has sponsored Lebedev`s EBSL research for the last four years, and seven US patents have been issued to Principia and the institute on the crystal technology. Principia is looking to develo¥large-area displays for electronic cinema screens.