Design of photonic crystal surface emitting lasers with indium-tin-oxide top claddings

Abstract

Electrically pumped GaAs-based photonic crystal surface emitting lasers were fabricated using a simple fabrication process by directly capping the indium-tin-oxide transparent conducting thin film as the top cladding layer upon a photonic crystal layer. Optimization of the separate-confinement heterostructures of a laser structure is crucial to improving characteristics by providing advantageous optical confinements. The turn-on voltage, series resistance, threshold current, and slope efficiency of the laser with a 100 x 100 mu m(2) photonic crystal area operated at room temperature were 1.3V, 1.5 Omega, 121mA, and 0.2W/A, respectively. Furthermore, we demonstrated a single-lobed lasing wavelength of 928.6 nm at 200mA and a wavelength redshift rate of 0.05 nm/K in temperature-dependent measurements. The device exhibited the maximum output power of approximately 400 mW at an injection current of 2 A; moreover, divergence angles of less than 1 degrees for the unpolarized circular-shaped laser beam were measured at various injection currents. Overall, the low threshold current, excellent beam quality, small divergence, high output power, and high-operating-temperature (up to 343K) of our devices indicate that they can potentially fill the requirements for next-generation light sources and optoelectronic devices. Published by AIP Publishing.