Green VCSELs based on nitride semiconductors

Abstract

Vertical-cavity surface-emitting lasers (VCSELs) are promising in various applications including full-color mobile projectors, laser precision processing, display, armarium and high-speed air-water optical wireless communication systems with a unique combination of advantages. However, GaN-based VCSELs with emission wavelengths in green are challenging because of the low emission efficiency of green emitting InGaN QWs. This is known as the "green gap", which is mainly caused by the quantum-confined Stark effect and the high density of defects and dislocations. In this paper, we would like to discuss the origin of the "green gap" and possible approaches to overcome it, and then review our recent progress in green VCSELs: (1) lasing from 479.6 to 565.7 nm by using QD active area; (2) lasing at 545 nm by using QD-in-QW active structure; (3) lasing at 493 nm by utilizing blue-emitting InGaN QWs with the combination of cavity effect.

Green Vertical-Cavity Surface-Emitting Lasers Based on InGaN Quantum Dots and Short Cavity

“…However, increasing In content will lead to stronger quantum confinement Stark effect (QCSE) and a higher density of defects due to the large lattice mismatch between GaN and InGaN [ 28 ]. In addition, the large effective mass of carriers in the GaN-based material system results in a higher transparent carrier density, which is another limitation to achieving low threshold green GaN-based VCSELs [ 29 ]. At present, the electrically injected green VCSELs based on c-plane InGaN QWs are only realized by Nichia in 2011 with double dielectric distributed Bragg reflector (DBR) structure [ 22 ], and in 2021 with hybrid DBR structure [ 27 ], respectively.…”

Simulation of performance enhancement of GaN-based VCSELs by composition gradient InGaN last-quantum barrier

“…Gallium nitride (GaN)-based vertical-cavity surface-emitting lasers (VCSELs) are attracting increasing attention due to their circular beam profile, low threshold current, high coupling efficiency with optical fiber, and ease of realization of twodimensional arrays [1][2][3]. They have great potential for solidstate lighting [4], displays [5], data communications [6], and high-density optical storage [7].…”

Design and simulation of vertical cavity surface emitting laser based on all-inorganic perovskite

“…While the VCSEL structure consisting of two layers of DBR has the advantages of small divergence angle, low threshold current, single longitudinal mode operation, high-speed modulation, etc [14][15][16][17][18] . VCSEL has been widely used in optical communication, optical storage, laser display, laser sensing and other fields [19][20][21][22][23] . Chen et al realized perovskites green light on rigid and flexible substrates, but the use of 10 pairs of alternating HfO2/SiO2 DBR with low reflectivity resulted in insufficient stimulated amplification of the incident light, reflecting a low Q factor of 1420 [24] .…”