Showing papers by "Nikolai N. Ledentsov published in 2014"
TL;DR: In this paper, the authors proposed an oxide-confined vertical cavity surface emitting laser (VCSEL) which allows leakage of the optical modes from the all-semiconductor core region to the selectively oxidized periphery if the orthogonality between the core mode and the modes on the periphery is broken by the oxidation-induced optical field redistribution.
Abstract: Properly designed oxide-confined vertical cavity surface emitting laser (VCSEL) allows leakage of the optical modes from the all-semiconductor core region to the selectively oxidized periphery if the orthogonality between the core mode and the modes on the periphery is broken by the oxidation-induced optical field redistribution. The leakage losses are stronger for high-order transverse modes, which have a higher field intensity close to the oxidized region. Single mode lasing in the fundamental mode can thus proceed up to large aperture diameters. The 850-nm GaAlAs thick oxide aperture VCSEL based on this concept is designed, modeled, and fabricated, showing single-mode lasing with the aperture diameters up to 5 \(\mu \mathrm {m}\) . Side mode suppression ratio >20 dB is realized at the current density of \(\sim 10\) kA/cm \(^{2}\) in devices with the series resistance of 90 \(\Omega \) .
45 citations
TL;DR: In this paper, high efficient fast vertical-cavity surface-emitting laser (VCSEL) for the 850-nm spectral range, promising for the development of optical interconnections with a data transmission rate of 25 Gbit/s per channel, is fabricated and studied.
Abstract: Highly efficient fast vertical-cavity surface-emitting lasers (VCSELs) for the 850-nm spectral range, promising for the development of optical interconnections with a data transmission rate of 25 Gbit/s per channel, are fabricated and studied. Lasers with a selectively oxidized current aperture 6 μm in diameter demonstrate multimode lasing with a quantum efficiency of 35–45% and a threshold current of 0.5–0.7 mA in the temperature range 20–85°C. According to the results of small-signal frequency analysis, the maximum modulation frequency of the lasers exceeds 17 GHz, with the rate of its increase with current exceeding 9 GHz/mA1/2, which provides VCSEL operation at a rate of 25 Gbit/s in the entire working temperature range. Endurance tests for 3000 h did not reveal any sudden degradation of the lasers. The optical power at working point and the threshold current changed relative to that at the beginning of the tests by no more than 5 and 10%, respectively.
4 citations