Browsing by Author "Zhang, Bao-Ping"

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Emission dynamics of GaN-based blue resonant-cavity light-emitting diodes
(2019-12-01)
Xu, Rong-Bin
;
Xu, Huan
;
Mei, Yang
;
Shi, Xiao-Ling
;
Ying, Lei-Ying
We fabricated GaN-based blue resonant-cavity light-emitting diodes (RCLEDs) by inserting InGaN quantum well (QW) active region between two dielectric distributed Bragg reflectors (DBRs). Due to the different gain enhancement factors in a single device, multi-longitudinal modes were observed and tuned with changing the injection current density: pure-blue (PB) at low current density, violet-blue (VB) at intermediate current density, and PB again at high current density. The variation of emission spectra is explained by the competition between band-filling effect and self-heating effect.
Quantum dot vertical-cavity surface-emitting lasers covering the 'green gap'
(2017-01-01)
Mei, Yang
;
Weng, Guo-En
;
Zhang, Bao-Ping
;
Liu, Jian-Ping
;
Hofmann, Werner
Semiconductor vertical-cavity surface-emitting lasers (VCSELs) with wavelengths from 491.8 to 565.7 nm, covering most of the 'green gap', are demonstrated. For these lasers, the same quantum dot (QD) active region was used, whereas the wavelength was controlled by adjusting the cavity length, which is difficult for edge-emitting lasers. Compared with reports in the literature for green VCSELs, our lasers have set a few world records for the lowest threshold, longest wavelength and continuous-wave (CW) lasing at room temperature. The nanoscale QDs contribute dominantly to the low threshold. The emitting wavelength depends on the electron-photon interaction or the coupling between the active layer and the optical field, which is modulated by the cavity length. The green VCSELs exhibit a low-thermal resistance of 915 kW(-1), which benefits the CW lasing. Such VCSELs are important for small-size, low power consumption full-color displays and projectors.
Quantum dot vertical-cavity surface-emitting lasers covering the \'green gap\'
(2017-01)
Mei, Yang
;
Weng, Guo-En
;
Zhang, Bao-Ping
;
Liu, Jian-Ping
;
Hofmann, Werner
Semiconductor vertical-cavity surface-emitting lasers (VCSELs) with wavelengths from 491.8 to 565.7 nm, covering most of the \'green gap\', are demonstrated. For these lasers, the same quantum dot (QD) active region was used, whereas the wavelength was controlled by adjusting the cavity length, which is difficult for edge-emitting lasers. Compared with reports in the literature for green VCSELs, our lasers have set a few world records for the lowest threshold, longest wavelength and continuous-wave (CW) lasing at room temperature. The nanoscale QDs contribute dominantly to the low threshold. The emitting wavelength depends on the electron-photon interaction or the coupling between the active layer and the optical field, which is modulated by the cavity length. The green VCSELs exhibit a low-thermal resistance of 915 kW(-1), which benefits the CW lasing. Such VCSELs are important for small-size, low power consumption full-color displays and projectors.