Advantages of III‐nitride laser diodes in solid‐state lighting

Abstract

III‐nitride laser diodes (LDs) are an interesting light source for solid‐state lighting (SSL). Modelling of LDs is performed to reveal the potential advantages over traditionally used light‐emitting diodes (LEDs). The first, and most notable, advantage is LDs have higher efficiency at higher currents when compared to LEDs. This is because Auger recombination that causes efficiency droop can no longer grow after laser threshold. Second, the same phosphor‐converted methods used with LEDs can also be used with LDs to produce white light with similar color rendering and color temperature. Third, producing white light from color mixed emitters is equally challenging for both LEDs and LDs, with neither source having a direct advantage. Fourth, the LD emission is directional and can be more readily captured and focused, leading to the possibility of novel and more compact luminaires. Finally, the smaller area and higher current density operation of LDs provides them with a potential cost advantage over LEDs. These advantages make LDs a compelling source for future SSL.

Nonpolar III-nitride vertical-cavity surface-emitting lasers incorporating an ion implanted aperture

“…10 Additionally, the ability to fabricate single mode VCSELs is not only a benefit for data transmission but also makes VCSELs highly sensitive devices for atomic clocks. [11][12][13][14][15] Finally, because VCSELs have emission normal to the substrate, they can be fabricated into high density 2D arrays, making III-nitride VCSELs ideal for visible and UV-A applications requiring high power density emission, including pico-projectors, 16 micro-displays, [17][18][19][20] backlighting for small electronics, 21 laser based lighting, [22][23][24] and bio-sensing. 25 In the arsenides, high power VCSEL arrays are now being manufactured to yield 9.6 kW emission for rapid industrial heating, proving the potential for these low power devices to yield high power arrays.…”

Progress and challenges in electrically pumped GaN-based VCSELs

“…If blue-emitting lasers would be used instead of the LEDs, a high-power conversion efficiency could be achieved at much higher current densities, and the much higher optical output power generated by a single device would correspond to a smaller area to achieve the same lumens, resulting potentially in a lower cost for laser-based lighting systems. [11][12] A VCSEL offers a more directional, circular-symmetric beam, which could lead to new and more compact luminaires at a low cost. In addition, the individually addressable elements in a two-dimensional VCSEL array would enable tailor-made, dynamic emission patterns for smart lighting systems.…”

Visible Lasers and Emerging Color Converters for Lighting and Visible Light Communications

“…OCIS codes: (060.2605) Free-space optical communication; (140.7300) Visible lasers; (230.3670) Light-emitting diodes; (230.5590) Quantum-well, -wire and -dot devices; (250.0250) Optoelectronics; (250.5960) Semiconductor lasers.The past decade witnessed the rapid development of III-nitride light-emitting diodes (LEDs) [1,2], superluminescent diodes (SLDs) [3,4], and laser diodes (LDs) [5,6], for solid-state lighting (SSL), visible-light communication (VLC), optical storage, and internet-of-things (IoT) [7,8]. InGaN/GaN quantum well (QW)-based LEDs have been established as the fundamental component for SSL applications while recent studies suggested that the GaN-based LDs, which is free from efficiency droop, may outperform LEDs as a viable high-power light source [9,10]. Meanwhile, there are increasing potentials in using such emitters in visible-light based optical communication systems for indoor and outdoor applications as data-rate demands are exponentially growing in the near future [8,11,12].…”