InGaN laser diodes with 50 mW output power emitting at 515 nm

Abstract

We demonstrate direct green laser operation from InGaN based diodes at wavelengths as long as 515.9 nm with 50 mW output power in pulse operation. A factor of ∼10 defect reduction for the In-rich InGaN quantum wells based on improvements of the epitaxial growth process and design of the active layers on c-plane GaN-substrates makes it possible to demonstrate laser operation at room temperature. Micrometer-scale photoluminescence mappings and electro-optical measurements confirm the reduction of nonradiative defects in the emitting layers. The 11 μm broad-area gain-guided laser structures were driven in pulse operation to minimize thermal effects and to accurately measure the laser temperature dependence. The threshold current density was ∼9 kA/cm2 and the fitted slope efficiency had a value of ∼130 mW/A for an optical output up to 50 mW.

Optical anisotropy in semipolar (Al,In)GaN laser waveguides

“…1 Introduction (Al,In)GaN Laser diodes grown on free-standing c-plane GaN substrates have been demonstrated at wavelengths up to 515 nm [1,2] with high external efficiencies and low threshold current densities. True green continuous wave laser diodes, which would be suitable for applications such as laser projection have not yet been realized, as an increase of the In-content in the active layers leads to inhomogeneous broadening due to spatial potential fluctuations and an increase of the piezoelectric polarization in the quantum wells.…”

Small signal modulation characteristics of red-emitting (λ = 610 nm) III-nitride nanowire array lasers on (001) silicon

“…5 These characteristics make them very suitable not only for use in communication systems but also in the display and medical applications listed above, which typically rely on planar InGaN/GaN quantum wells (QWs). [6][7][8] The nanowire devices have further advantages of planar InGaN/GaN QW lasers which must be grown on expensive polar or non-polar GaN substrates, suffer from large defect densities, and from which emission can currently only reach green ($530 nm). The nanowire heterostructures, on the other hand, can be grown on cheap (001) or (111) silicon substrates.…”

Thermodynamic analysis on HVPE growth of InGaN ternary alloy

“…For applications to full-color LED displays and optical communication technology, there is a growing interest in InGaN-based optical devices with longer emission wavelengths, such as LDs emitting at green, red or near-infrared wavelengths. However, the longest wavelength of nitride lasers has been limited to about 530 nm [1][2][3][4][5]. This is considered to be attributed in part to the large lattice mismatch between the substrate and epitaxial layer [6].…”