Vertical-cavity electrically driven lasers with three GaInAs
quantum wells and diameters of several μm exhibit room-temperature pulsed current thresholds as low as 1.3mA with 958 nm output wavelength.

Low-Threshold Electrically Pumps Vertical-Cavity Surface-Emitting Microlasers

This paper reviews current technological developments in polarization engineering and the control of the quantum-confined Stark effect (QCSE) for InxGa1- xN-based quantum-well active regions, which are generally employed in visible LEDs for solid-state lighting applications. First, the origin of the QCSE in III-N wurtzite semiconductors is introduced, and polarization-induced internal fields are discussed in order to provide contextual background. Next, the optical and electrical properties of InxGa1- xN-based quantum wells that are affected by the QCSE are described. Finally, several methods for controlling the QCSE of InxGa1- xN-based quantum wells are discussed in the context of performance metrics of visible light emitters, considering both pros and cons. These strategies include doping control, strain/polarization field/electronic band structure control, growth direction control, and crystalline structure control.

Control of Quantum-Confined Stark Effect in InGaN-Based Quantum Wells

The vertical-cavity surface-emitting laser (VCSEL) has become a light source of great importance for industrial and consumer applications. This includes communication and sensing in particular, where dynamics and optical mode behavior are key performance characteristics. This tutorial treats relevant VCSEL basics, performance requirements and recent progress toward higher speed, higher single-mode power, and polarization control.

Advances in VCSELs for Communication and Sensing

Physics of optoelectronic devices

A Group III-V nitride microelectronic device structure including a delta doped layer (24) and/or a doped superlattice. A delta doping method is described, including the steps of: depositing semiconductor material on a substrate by a first epitaxial film growth process; terminating the deposition of semiconductor material on the substrate to present an epitaxial film surface; delta doping the semiconductor material at the epitaxial film surface, to form a delta doping layer thereon; terminating the delta doping; resuming deposition of semiconductor material to deposit semiconductor material on the delta doping layer, in a second epitaxial film growth process; and continuing the semiconductor material second epitaxial film growth process to a predetermined extent, to form a doped microelectronic device structure, wherein the delta doping layer (24) is internalized in semiconductor material deposited in the first and second epitaxial film growth processes.

Doped group iii-v nitride materials, and microelectronic devices and device precursor structures comprising same

In this paper, use of a comprehensive self-consistent optical–electrical–thermal–gain threshold model of oxide-confined GaAs-based (GaIn)(NAs)/GaAs quantum-well vertical-cavity surface-emitting diode lasers (VCSELs) is demonstrated. The model was developed to facilitate better understanding of the physics of operation of the above devices including the full complexity of the many interactions, in the volumes of the devices, between individual physical phenomena. Besides this, the model was applied in designing and optimizing such VCSELs for long-wavelength 1.3 µm second-generation optical fibre communication system use and for examining their anticipated continuous-wave (CW) room-temperature (RT) low-threshold performance. The influences of many construction parameters on device CW RT lasing thresholds and mode selectivity were investigated. Some essential design guidelines were proposed to support efforts of technological centres to produce low-threshold single-mode RT CW devices. In particular, the 1.5λ-cavity VCSELs have been found to exhibit lower RT CW lasing thresholds, whereas the 3λ-cavity ones offer better thermal properties: higher values of the parameter T0 and single-fundamental-mode operation possible at higher temperatures. As expected, the desired stable RT CW single-fundamental-mode operation is possible in smaller VCSELs (with active-region diameters not exceeding 6 µm in the case of the 1.5λ-cavity VCSELs). A deliberate detuning of the lasing mode from the RT active-region optical peak gain towards higher wavelengths ensures better device operation at higher temperatures.

https://iopscience.iop.org/article/10.1088/0953-8984/16/31/009/pdf

Optimization of 1.3 µm GaAs-based oxide-confined (GaIn)(NAs) vertical-cavity surface-emitting lasers for low-threshold room-temperature operation

The transient thermal properties of high-power diode laser bars with active and passive cooling are analyzed. Both thermal imaging and the analysis of the thermal wavelength tuning behavior are employed to extract the device temperature as a function of time. A steady-state thermal situation is established with rise times of about 10 and 60ms for active and passive cooling, respectively. The latter number, however, is substantially increased by the particular properties of the external heat sink. Such results are confirmed by model calculations based on the finite element method.

Transient thermal properties of high-power diode laser bars

A new design of vertical external cavity surface emitting laser (VECSEL) with diamond-based high contrast gratings is proposed. The self-consistent model of laser operation has been calibrated based on experimental results and used to optimize the new proposed device and to perform comparative thermal and optical analysis of conventional and double-diamond high-contrast-grating VECSELs. The proposed design considerably reduces the dimensions and complexity of the device and provides up to 80% increase of the maximum emitted power as compared with the conventional design.

https://iopscience.iop.org/article/10.1088/0022-3727/47/6/065104/pdf

Double-diamond high-contrast-gratings vertical external cavity surface emitting laser

In the paper, the self-consistent optical-electrical-thermal-gain threshold model of the oxide-confined (OC) quantum-dot (QD) (InGa)As-GaAs vertical-cavity surface-emitting diode laser (VCSEL) is demonstrated. The model has been developed to enable better understanding of physics of an operation of GaAs-based OC QD VCSELs in a full complexity of many interactions in its volume between individual physical phenomena. In addition, the model has been applied to design and optimize the low-threshold long-wavelength 1.3-/spl mu/m GaAs-based OC QD VCSELs for the second-generation optical-fiber communication systems and to examine their anticipated room-temperature (RT) performance. An influence of many construction parameters on device RT lasing thresholds and mode selectivity has been investigated. Some essential design guidelines have been proposed to support efforts of technological centers in producing low-threshold single-mode RT devices.

Robert P. Sarzała

Papers

Optimization of 1.3 µm GaAs-based oxide-confined (GaIn)(NAs) vertical-cavity surface-emitting lasers for low-threshold room-temperature operation

Transient thermal properties of high-power diode laser bars

Double-diamond high-contrast-gratings vertical external cavity surface emitting laser

Modeling of the threshold operation of 1.3-/spl mu/m GaAs-based oxide-confined (InGa)As-GaAs quantum-dot vertical-cavity surface-emitting lasers

Transverse modes in gain-guided vertical-cavity surface-emitting lasers