GaN Photonic-Crystal Surface-Emitting Laser at Blue-Violet Wavelengths

Abstract

Shorter-wavelength surface-emitting laser sources are important for a variety of fields, including photonics, information processing, and biology. We report on the creation of a current-driven blue-violet photonic-crystal surface-emitting laser. We have developed a fabrication method, named "air holes retained over growth," in order to construct a two-dimensional gallium nitride (GaN)/air photonic-crystal structure. The resulting periodic structure has a photonic-crystal band-edge effect sufficient for the successful operation of a current-injection surface-emitting laser. This represents an important step in the development of laser sources that could be focused to a size much less than the wavelength and be integrated two-dimensionally at such short wavelengths.

Bound states in the continuum

“…Researchers first observed this effect via a suppression of radiation into the normal direction in a surface-emitting distributed feedback laser with onedimensional periodicity 58,59 . This led to PhC surface emitting lasers (PCSELs) that lase through BICs with two-dimensional periodicity 214,215 , followed by the realizations of various lasing patterns 216,217 , lasing at the blue-violet wavelengths 218 , and lasing with organic molecules 221 . The suppressed radiation at the normal direction means that a PCSEL can have a low lasing threshold but also with a limited output power.…”

“…This makes them useful for many optical and photonic applications. In particular, the macroscopic size (on the centimeter scale or larger) and ease of fabrication make BICs in PhC slabs unique for large-area high-power applications such as lasers [214][215][216][217][218][219] , sensors 220,221 , and filters 222 .…”

Coupled Mode Theory of Photonic Crystal Lasers

“…They also allow to control the output beam pattern by manipulation of the primitive cell geometry (Iwahashi et al (2010); Miyai et al (2006)), provide low threshold (Susa (2001)), and beams which can be focused to a size less than the wavelength (Matsubara et al (2008)). …”

Photonic crystal: energy-related applications

“…There are applications that we did not discuss here but are no less important, such as those in light emitting 14,15 (lasers and LEDs) based on the Purcell effect, 61 and in sunlight harvesting taking advantage of slow photons, 62 among others. In the last two decades, PCs have matured from an intellectual curiosity to a field with real applications.…”