Challenges and Advancement of Blue III-Nitride Vertical-Cavity Surface-Emitting Lasers
| Autor: | Zhen Ting Huang, Wen Hsuan Hsieh, Kuo-Bin Hong, Wei Hao Huang, Chia-Yen Huang, Tien-Chang Lu |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Aperture Physics::Optics Review 02 engineering and technology Dielectric Grating VCSEL 01 natural sciences GaN Vertical-cavity surface-emitting laser law.invention Condensed Matter::Materials Science law 0103 physical sciences TJ1-1570 Mechanical engineering and machinery Electrical and Electronic Engineering 010302 applied physics polarization business.industry Mechanical Engineering III-nitrides 021001 nanoscience & nanotechnology Polarization (waves) Distributed Bragg reflector Laser Control and Systems Engineering distributed Bragg reflector Optoelectronics carrier aperture 0210 nano-technology business Lasing threshold |
| Zdroj: | Micromachines, Vol 12, Iss 676, p 676 (2021) Micromachines |
| ISSN: | 2072-666X |
| Popis: | Since the first demonstration of (Al, In, Ga)N-based blue vertical-cavity surface-emitting lasers (VCSELs) in 2008, the maximum output power (Pmax) and threshold current density (Jth) has been improved significantly after a decade of technology advancements. This article reviewed the key challenges for the realization of VCSELs with III-nitride materials, such as inherent polarization effects, difficulties in distributed Bragg’s reflectors (DBR) fabrication for a resonant cavity, and the anti-guiding effect due to the deposited dielectrics current aperture. The significant tensile strain between AlN and GaN hampered the intuitive cavity design with two epitaxial DBRs from arsenide-based VCSELs. Therefore, many alternative cavity structures and processing technologies were developed; for example, lattice-matched AlInN/GaN DBR, nano-porous DBR, or double dielectric DBRs via various overgrowth or film transfer processing strategies. The anti-guiding effect was overcome by integrating a fully planar or slightly convex DBR as one of the reflectors. Special designs to limit the emission polarization in a circular aperture were also summarized. Growing VCSELs on low-symmetry non-polar and semipolar planes discriminates the optical gain along different crystal orientations. A deliberately designed high-contrast grating could differentiate the reflectivity between the transverse-electric field and transverse-magnetic field, which restricts the lasing mode to be the one with the higher reflectivity. In the future, the III-nitride based VCSEL shall keep advancing in total power, applicable spectral region, and ultra-low threshold pumping density with the novel device structure design and processing technologies. |
| Databáze: | OpenAIRE |
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