Low-threshold buried-ridge II-VI laser diodes

Abstract

Blue-green (λ=511 nm) separate confinement laser structures based on lattice-matched MgZnSSe-ZnSSe-CdZnSe have been grown by molecular beam epitaxy. Wide stripe gain-guided devices have been fabricated from several such wafers. These devices exhibit room-temperature pulsed threshold current densities as low as 630 A/cm2 and threshold voltages less than 9 V. Using a novel self-aligned process that results in a planar surface, buried-ridge laser diodes have also been fabricated. These devices have demonstrated room-temperature threshold currents as low as 2.5 mA, which is more than a factor of 50 lower than that of any previously reported II-VI laser diode. Room-temperature operation at duty factors up to 50% has been demonstrated. The far-field patterns from these devices indicate single lateral mode operation, suitable for diffraction-limited applications, such as optical data storage.

Fabrication of ZnCdSe quantum dots under Stranski–Krastanow mode

“…For example, laser diodes based on ZnCdSe have been successfully demonstrated to operate under a continuous-wave mode at room temperature [3]. Quantum dots, which have 3D confinement to electrons and holes, can produce higher quantum efficiency than 2D quantum wells and 1D quantum wires [4].…”

ZnMgSSe/ZnSe/CdSe quantum dot heterostructures for green laser applications

“…The most appropriate candidates, lasers diodes based on ZnSe heterostructures were fabricated for the first time in the early 90s [1,2], and up to now, their lifetime is still limited by ∼400 h in a cw regime [3] because of the non-stable nature of the nitrogen acceptor. The mechanism responsible for the slow degradation of ZnSe-based lasers is most often explained by compensating donor centers, i.e.…”

Fabrication of ZnSe quantum dots under Volmer–Weber mode by metalorganic chemical vapor deposition

“…Laser diodes based on ZnSe were successfully demonstrated to operate under cw mode at room temperature. 1,2 To the best of our knowledge, the longest lifetime reported was 100 h. How to prolong the lifetime remains a key challenge. Both the p-type contacting problem and the high defect density hinder this job.…”