Monolithically multi-color lasing from an InGaN microdisk on a Si substrate

Abstract

An optically pumped multi-color laser has been achieved using an InGaN/GaN based micro-disk with an undercut structure on a silicon substrate. The micro-disk laser has been fabricated by means of a combination of a cost-effective microsphere lithography technique and subsequent dry/wet etching processes. The microdisk laser is approximately 1 μm in diameter. The structure was designed in such a way that the vertical components of the whispering gallery (WG) modes formed can be effectively suppressed. Consequently, three clean lasing peaks at 442 nm, 493 nm and 522 nm have been achieved at room temperature by simply using a continuous-wave diode laser as an optical pumping source. Time–resolved micro photoluminescence (PL) measurements have been performed in order to further confirm the lasing by investigating the excitonic recombination dynamics of these lasing peaks. A three dimensional finite-difference-time-domain (FDTD) simulation has been used for the structure design.

Multilayer Fabrication of a Rainbow of Microdisk Laser Particles Across a 500 nm Bandwidth

“…As an alternative to photolithography, densely packed microspheres could be arranged on the wafer surface to form a hard etch mask. 26 This could theoretically enable α to approach the diameter of the disk. It should be possible to increase the number of layers to m > 9.…”

“…While our fabrication procedure has used α = 6 μm due to the limited resolution of our contact lithography tool, higher quality projection exposure systems could further decrease the spacing. As an alternative to photolithography, densely packed microspheres could be arranged on the wafer surface to form a hard etch mask . This could theoretically enable α to approach the diameter of the disk.…”

“…24,25 Furthermore, multiple III-nitride quantum wells of different compositions have been layered in a semiconductor microlaser to demonstrate simultaneous multicolor lasing from a single resonator. 26 However, unlike these studies in which multiple layers act in concert to form a single laser device on a chip, the active materials of our multilayer structure are designed to lase independently. Each resultant LP arises from a single gain material, and is separated from others to be released directly into an aqueous suspension.…”

“…Multilayer, stacked heterostructures have previously been used to form lasers including the widely used vertical cavity surface emitting laser (VCSEL) . Lasing from vertically layered cavities made of III–V heterostructures has also been demonstrated in the context of studying mode-splitting phenomena in coupled cavities. , Furthermore, multiple III-nitride quantum wells of different compositions have been layered in a semiconductor microlaser to demonstrate simultaneous multicolor lasing from a single resonator . However, unlike these studies in which multiple layers act in concert to form a single laser device on a chip, the active materials of our multilayer structure are designed to lase independently.…”

Realizing Single Chip White Light InGaN LED via Dual-Wavelength Multiple Quantum Wells

“…Other researchers report a white light emission through InGaN/GaN nanorods or truncated pyramid structures [ 12 , 13 , 14 ]. In addition, the optically pumped monolithically multi-color lasing is demonstrated from an InGaN microdisk structure [ 15 ]. Wang et al fabricate a 3D InGaN/GaN MQWs LED structure, the colors of which could be tuned from red to blue [ 9 ].…”