Evaluating resonances in PCSEL structures based on modal indices (original) (raw)
Related papers
IEEE Journal of Selected Topics in Quantum Electronics
We present a novel semi-analytical method utilising modal index analysis, for modelling the field resonances of photonic crystal surface emitting lasers (PCSELs). This method shows very good agreement with other modelling techniques in terms of mode calculations, with the added advantages of computational simplicity, the calculation of threshold gain, and rapid analysis of finite structures. We are able to model the effect of external lateral feedback and simulations indicate that the nearfield peak can be electronically displaced and the threshold as well as the frequency can be controlled through external in-plane feedback, paving the way to dynamic control of PCSELs.
Novel In-Plane Semiconductor Lasers XV, 2016
We investigate the beam divergence in far-field region, diffraction loss and optical confinement factors of allsemiconductor and void-semiconductor photonic-crystal surface-emitting lasers (PCSELs), containing either InGaP/GaAs or InGaP/air photonic crystals using a three-dimensional FDTD model. We explore the impact of changing the PC hole shape, size, and lattice structure in addition to the choice of all-semiconductor or void-semiconductor designs. We discuss the determination of the threshold gain from the diffraction losses, and explore limitations to direct modulation of the PCSEL.
Optical and Quantum Electronics, 2007
A three-dimensional, full vectorial model has been applied for investigation the modal characteristics of a phosphide photonic-crystal vertical-cavity surface-emitting diode laser. The photonic crystal has been defined as a regular, hexagonal net of holes, etched in the upper, p-type Distributed Bragg Reflector of the laser. The electromagnetic field has been confined to the active region by a single defect of the photonic crystal providing overlapping with carriers funneled by a tunnel junction. We have determined the range of design parameters, which provide single mode operation.
Design of Low-Threshold Photonic Crystal Surface-Emitting Lasers
IEEE Photonics Technology Letters, 2012
We have investigated the influence of various thicknesses on different layers in GaAs-based photonic crystal surface-emitting lasers (PCSELs), by using the transfer matrix and coupled wave methods to increase the vertically optical confinement factor and to reduce the threshold gain. In addition, the relationship between the threshold gain and the filling factor has been considered. This letter provides an efficient calculation method for designing square-lattice-type PCSEL structures, which shall be useful for the fabrication of low-threshold PCSELs in the near future.
Directly modulated vertical-cavity surface-emitting lasers (VCSELs) are the dominant digital light source in shorthaul data communication links. To address the ever-increasing demand for improved performance, namely the power consumption, data rate, and device reliability, single mode proton-implanted photonic crystal vertical-cavity surface-emitting lasers have been designed and fabricated for high power and high speed operation. To characterize performance of these devices, we perform DC and small signal modulation analysis. Impedance characteristics and electrical parasitics are studied for various photonic crystal designs to understand factors which limit high speed modulation. Photonic crystal designs are found to have low differential resistance, but high parasitic capacitance. By including a diffusion capacitance term in the modulation response equation, scattering parameter fitting suggests the diffusion capacitance to be the limiting factor of intensity modulation. Extracted parameters from DC, impedance, and modulation response measurements are cross-checked to verify accuracy.
Journal of the Optical Society of America B, 2010
The performance of vertical cavity surface emitting lasers can be enhanced, while simplifying the fabrication process, by adopting a hybrid design using a photonic-crystal (PhC) top mirror. In this paper, we analyze the performance of photonic-crystal surface emitting lasers (PCSELs) by varying the number of periods in the PhC mirror and estimating its reflectivity and lateral radiation losses. We consider three types of PhC mirrors: a simply periodic structure, a structure with a constant period but a variable filling factor (FF), and a structure with a constant FF but a variable period. We show that lateral losses can pose a serious limitation on the minimum size required to achieve an efficient PCSEL operation. We also show that our special structure can convert vertically emitted light into an in-plane light that propagates in the same plane as the PhC mirror creating the possibility of coupling vertically emitted light into optical waveguides.
Laser Resonators, Microresonators, and Beam Control XIX, 2017
before moving to Agilent Technologies Fibre-Optic Component Operation in Ipswich, UK, in 2000. In 2003 he joined the Electronic and Electrical Engineering Department of the University of Sheffield. In 2015 he became Professor of Electronic and Nanoscale Engineering at the University of Glasgow. His research group is active in developing the understanding of device physics and engineering, epitaxial processes fabrication technologies, and applications of various semiconductor laser, amplifier, and super-luminescent diode devices.
Journal of Lightwave Technology, 1998
Accurate vector finite element solutions for threedimensional (3-D) axisymmetric multilayered optical cavities are presented. Resonating wavelength and field profiles are shown for the fundamental and higher order modes for different types of optical cavities. The work has shown that for a narrow multilayered cylinder of diameter 0.5 m, for miniature vertical cavity surface emitting lasers (VCSEL), which is a popular class of laser showing favorable performance characteristics, the effect of waveguide dispersion is an important factor. This causes a blue shift of the output wavelength, requiring an adjustment to the layer thickness in the system design, to achieve the desired wavelength. The results of the simulation show close agreement with features obtained through experimental investigations.
Optical and Quantum Electronics, 2010
A dynamical model of oxide-confined Vertical-Cavity Surface-Emitting Lasers (VCSELs) with two-dimensional photonic crystals (PCs) incorporated within them so called PC-VCSELs is presented and used to optimise designs for high-power single-mode operation. Three PC-VCSEL designs are considered: (I) with holes in the top DBRs, (II) with PC holes situated between their DBRs and (III) with PC holes etched through the entire VCSEL. A simulated design for a PC-VCSEL of type (I) with holes of d = 2 µm diameter, a = 4 µm lattice constant (d/a = 0.5) and 2.2 µm depth was found to improve the single mode behaviour but not enough to establish single mode behaviour for large apertures. The modulation behaviour was not degraded by the PC. Simulations of type (II) and (III) PC-VCSELs, with the same parameters, have shown multimode operation and degraded modulation properties. Simulations of PC-VCSELs of type (III) with holes of d = 0.2 µm diameter and a = 0.4 µm lattice constant (d/a = 0.5) have shown improved modulation properties and enhanced single mode power for small apertures. In simulation, PC-VCSELs incorporating multiple PC-defects have shown order of magnitude increases in the single mode output power. However, the modulation properties of these VCSELs show degradation due to gain saturation and hopping of the optical modes localized within the PC defects.
Optimal Parameters of Photonic-Crystal Vertical-Cavity Surface-Emitting Diode Lasers
IEEE/OSA Journal of Lightwave Technology, 2007
We investigate the modal characteristics of a 1300-nm InP-based photonic-crystal (PC) vertical-cavity surfaceemitting diode laser. To this aim, we apply the plane-wave admittance method and analyze a broad range of PC parameters such as hole etching depth, distance between the holes, and their diameters. We determine a range of technologically feasible PC parameters providing an optimal laser performance.