160-GHz 1.55-$\mu{\rm m}$ Colliding-Pulse Mode-Locked AlGaInAs/InP Laser With High Power and Low Divergence Angle

IEEE J. Select. Topics Quantum Electron.

et al. 2015

High-power low-vertical-divergence laser diodes based on the longitudinal photonic band crystal (PBC) concept are investigated at a wavelength of 900 nm. The thicknesses of the layers in the longitudinal PBC waveguide are prudently optimized by mode analysis, and the lowest vertical far-field angle is found to be achieved by mode coupling. A self-consistent model is also utilized to study the device performances in detail, which shows excellent optical properties without obvious electronic performance degradation. In the experiment, continuous wave power up to 1 W/facet and vertical far-field angles of less than 10°(fullwidth at half-maximum) and ß50°(with 95% power content) are achieved simultaneously, with epitaxial wafer containing PBC layers of ten periods. The agreement among the design, simulation, and experiment shows a bright prospect for further reduced vertical divergence angle with high power output.Index Terms-Laser beam, laser diodes, quantum well lasers, beam divergence.

Section: Introductionmentioning

confidence: 99%

Design and Analysis of Laser Diodes Based on the Longitudinal Photonic Band Crystal Concept for High Power and Narrow Vertical Divergence

IEEE J. Select. Topics Quantum Electron.

et al. 2015

“…Plenty of structures have been presented to reduce the transverse far-field angle, such as the asymmetric waveguide [6], the large optical cavity structure [7], [8], the passive far-field reduction layer (FRL) [9] and the longitudinal photonic band crystal (PBC) waveguide [10], and the narrowest angle achieved is about 5° [10]. However, these designs are all based on the introduction of additional layers below Manuscript the quantum wells (QWs), which need precisely modification of the epitaxial structure and may affect the growth quality of the QWs.…”

Section: Introductionmentioning

confidence: 99%

High-Performance Low-Divergence Angled Laser Diodes With Two-Dimensionally Tilted Sidewalls

IEEE Photon. Technol. Lett.

et al. 2014

High-performance low-divergence angled laser diodes are proposed and fabricated at a wavelength of 910 nm. Light is reflected both inward to the waveguide and downward to the lower cladding layer by the 2-D tilted sidewalls along its zigzag path in the waveguide, and thus the mode field is extended and the transverse divergence angle is greatly reduced. Experimentally, reduced transverse divergence angles by over 20°a re demonstrated in both pulse and continuous wave modes, and stable and narrow lateral divergence angles are simultaneously achieved. This device shows a promising future for improving the transverse far-field pattern by surface structure with easy fabrication.Index Terms-Laser beam, laser diodes, quantum well lasers, beam divergence.

High-power narrow-vertical-divergence photonic band crystal laser diodes with optimized epitaxial structure

Applied Physics Letters

et al. 2014