Optically Pumped GaN-based Vertical Cavity Surface Emitting Lasers: Technology and Characteristics (original) (raw)
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IEEE Photonics Technology Letters, 2000
The characteristics of a GaN-based vertical-cavity surface-emitting laser (VCSEL) with 25 pairs AlN-GaN distributed Bragg reflector (DBR) and eight pairs Ta 2 O 5 -SiO 2 DBR was investigated and analyzed under the optical pumping at room temperature. The GaN-based VCSEL emits a blue wavelength at 448 nm with a linewidth of 0.17 nm with a near-field emission spot diameter of about 3 m. The laser beam has a near linear polarization with a degree of polarization of about 84%. The laser shows a high spontaneous emission coupling efficiency of about 5 10 2 and a high characteristic temperature of about 244 K. Index Terms-AlN, distributed Bragg reflector (DBR), GaN, vertical-cavity surface-emitting laser (VCSEL).
Emission characteristics of optically pumped GaN-based vertical-cavity surface-emitting lasers
Applied Physics Letters, 2006
The laser emission characteristics of a GaN-based vertical-cavity surface-emitting laser with two dielectric distributed Bragg reflectors were investigated under optically pumped operation at room temperature. The laser emitted wavelength at 415.9 nm with an emission linewidth of 0.25 nm and threshold pumping energy of 270 nJ. The laser has a high characteristic temperature of about 278 K and high spontaneous emission coupling factor of 10 −2 . The laser emission showed single and multiple spot emission patterns with spectral and spatial variations under different pumping conditions.
Characteristics of Current-Injected GaN-Based Vertical-Cavity Surface-Emitting Lasers
IEEE Journal of Selected Topics in Quantum Electronics, 2011
This paper reviews the fabrication technology and performance characteristics of current-injected GaN-based vertical-cavity surface-emitting lasers (VCSELs) with hybrid distributed Bragg reflectors (DBRs). The GaN-based VCSEL consists of a ten-pair Ta 2 O 5 /SiO 2 top DBR, a 7λ-thick optical cavity embedded with 10 InGaN/GaN multiquantum wells, and a 29-pair AlN/GaN bottom DBR. Lasing action is observed under continuous-wave operation at room temperature. The laser characteristics, such as temperature-dependent laser threshold current, emission wavelength, and spontaneous emission coupling factors, have been measured and discussed.
Japanese Journal of Applied Physics, 2006
Room-temperature optically pumped GaN-based vertical-cavity surface-emitting lasers (VCSELs) were demonstrated by laser lift-off. A VCSEL was fabricated by combining a GaN-based cavity with two dielectric distributed Bragg reflectors: SiO 2 / TiO 2 and SiO 2 /Ta 2 O 5 . The Q factor of the VCSEL is 518 indicating a good interfacial layer quality of the structure. The laser emits blue-violet wavelength light at 414 nm under optical pumping at room temperature with a threshold pumping energy of 270 nJ. The laser emission has a narrow linewidth of 0.25 nm and a degree of polarization of 70%. The laser emission patterns clearly indicate a vertical lasing action of the VCSEL.
GaN-based vertical cavity lasers with semiconductor/dielectric and all dielectric reflectors
Gallium Nitride Materials and Devices VIII, 2013
GaN-based vertical cavity structures containing bottom AlN/GaN DBRs with top dielectric DBRs on freestanding c-GaN and all dielectric DBRs on GaN on c-sapphire were investigated. Epitaxial lateral overgrowth (ELO) technique allowed the use of both top and bottom all dielectric reflector stacks without substrate removal and the fabrication of the active region containing InGaN multiple quantum wells entirely on the nearly defect-free laterally grown wing regions to avoid nonradiative centers caused by extended and point defects. Compared with the cavity containing hybrid-DBRs on freestanding GaN, the cavity with all dielectric DBRs exhibited quality factors up to 1200 at high optical excitation and an order of magnitude lower stimulated emission threshold density (nearly 5 μJ/cm 2 ). Vertical to lateral growth ratio for ELO could be enhanced up to 5 by increasing the V/III ratio and employment of NH 3 modulation, which minimizes the use of dry etching to reduce the cavity thickness and therefore is promising for high quality vertical cavities with all dielectric DBRs.
Applied Physics Letters, 2016
A GaN-based vertical-cavity surface emitting laser (VCSEL) structure featuring a silicon-diffusion-defined current blocking layer for lateral confinement is described. Sub-milliamp threshold currents were achieved for both 3- and 5-μm-aperture VCSELs under continuous-wave operation at room temperature. The vertical cavity was defined by a top dielectric distributed Bragg reflector (DBR) and a bottom epitaxial DBR. The emission spectrum exhibited a single peak at 411.2 nm with a linewidth of 0.4 nm and a side mode suppression ratio of more than 10 dB before device packaging. The full-width-at-half-maximum divergence angle of the 3-μm-aperture VCSEL was as small as approximately 5° which is the lowest number reported. These results implied the 3-μm-aperture VCSEL was in near single-mode operation.
GaN-based vertical-cavity surface-emitting laser incorporating a TiO2 high-index-contrast grating
2020
We have achieved room-temperature CW operations of GaN-based vertical cavity surface emitting lasers (VCSELs) with periodic gain structures (PGSs). The PGS-VCSEL consisted of 4.5λ-thick optical cavity length and two GaInN 5-quantum-well (QW) active regions separated with a Mgdoped GaN intermediate layer. The uniform carrier injection into the two active regions was also investigated using light-emitting diodes (LEDs). It is found that the use of an optimum Mg concentration in the intermediate layers improves the uniform carrier injection in the two active regions. From these results, we realized the CW operation of VCSELs with PGSs grown on AlInN/GaN distributed Bragg reflectors (DBRs). The VCSEL under CW operation showed a threshold current density of 16.5 kA/cm 2 and its operation wavelength was 409.9 nm.
CW lasing of current injection blue GaN-based vertical cavity surface emitting laser
Applied Physics Letters, 2008
Here, we report the cw laser operation of electrically pumped GaN-based vertical cavity surface emitting laser ͑VCSEL͒. The GaN-based VCSEL has a ten-pair InGaN / GaN multiple quantum well active layer embedded in a GaN hybrid microcavity of 5 optical thickness with two high reflectivity mirrors provided by an epitaxially grown AlN / GaN distributed Bragg reflector ͑DBR͒ and a Ta 2 O 5 / SiO 2 dielectric DBR. cw laser action was achieved at a threshold injection current of 1.4 mA at 77 K. The laser emitted a blue wavelength at 462 nm with a narrow linewidth of about 0.15 nm. The laser beam has a divergence angle of about 11.7°with a polarization ratio of 80%. A very strong spontaneous coupling efficiency of 7.5ϫ 10 −2 was measured.
Development of GaN-Based Vertical-Cavity Surface-Emitting Lasers
IEEE Journal of Selected Topics in Quantum Electronics, 2009
In 2006, he joined the Semiconductor Laser Technology Laboratory, National Chiao-Tung University. His current research interests include LEDs, GaN vertical-cavity surface-emitting laser (VCSEL), high-Q microcavity LED, and photonic crystal surface-emitting lasers that can be applied to short-range fiber optical communication such as gigabit Ethernet and fiber channel.