Papers by Slawomir Sujecki
IEE Proceedings - Optoelectronics, 1998
ABSTRACT The spectral index method (SIM) for analysis of the rib waveguide in air is improved by ... more ABSTRACT The spectral index method (SIM) for analysis of the rib waveguide in air is improved by including the singular behaviour of the principal field component in the vicinity of the reentrant corners, thereby giving the singular SIM (SSIM). This generally improves the value of the modal propagation constant as compared with more exact solutions. The new approach is successfully extended further to the rib waveguide coupler
IEE Proceedings - Optoelectronics, 2006
ABSTRACT Using a quantitatively calibrated imaging system and specially fabricated tapered lasers... more ABSTRACT Using a quantitatively calibrated imaging system and specially fabricated tapered lasers with windowed n-contacts, the authors image the spontaneous emission distribution inside two different laser cavities as a function of injection current. In the first device, an array of narrow-angle index-guided tapered lasers, significant thermal and electrical coupling between the emitters was observed. In the second device, a wide-angle gain-guided tapered laser, significant spatial hole burning was observed above threshold. The spontaneous emission distributions of this wide-angle device have been compared with simulation results from a 2.5D laser simulator and show good quantitative agreement in the quantum well carrier density.
2008 International Semiconductor Conference, 2008
ABSTRACT Dilute-nitride-based edge-emitting Fabry-Perot lasers with record performances have been... more ABSTRACT Dilute-nitride-based edge-emitting Fabry-Perot lasers with record performances have been used to build un-cooled optical transceiver modules. The paper presents and analyses some of the achieved performances starting from chip level to optical link transmission experiments. The studies, performed within the EU-FP6 project fast access, prove that the dilute-nitride GaInAsN lasers are a good solution for low-cost un-cooled transmitters targeting short and medium distance optical communications in a wide range of applications, from supercomputers and server farms to metropolitan and access area networks.
2007 European Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference, 2007
This work present simulations of the operation of tapered semiconductor lasers with separate cont... more This work present simulations of the operation of tapered semiconductor lasers with separate contacts, in comparison with the experimental results, with the goal of providing a physical understanding of the origin of this improvement. The simulation parameters related to the fabrication technology were calibrated by comparison with experiments in broad area lasers and in tapered lasers with common contacts. The
Proceedings of 2002 4th International Conference on Transparent Optical Networks (IEEE Cat. No.02EX551), 2002
High performance fibre EDFA amplifiers for dense WDM systems require efficient and economic pumpi... more High performance fibre EDFA amplifiers for dense WDM systems require efficient and economic pumping devices. One way of providing high pumping power to an EDFA amplifier at low cost is to use tapered semiconductor lasers. The development of a software package for the design and optimisation of these high power tapered laser diodes is described. Cold cavity modelling enables the
Proceedings of 2004 6th International Conference on Transparent Optical Networks (IEEE Cat. No.04EX804), 2004
An advanced steady state semiconductor laser model is used to analyse the characteristics of high... more An advanced steady state semiconductor laser model is used to analyse the characteristics of high power laser diodes used for pumping erbium doped amplifiers. The laser model solves the bipolar current continuity equations in the bulk and quantum well regions, the thermal conduction equation and the optical wave equation in the travelling wave approximation using the 2D wide-angle beam propagation
CLEO/Europe. 2005 Conference on Lasers and Electro-Optics Europe, 2005., 2005
In this letter we present a new fully index-guided tapered laser design showing a balance between... more In this letter we present a new fully index-guided tapered laser design showing a balance between the competing mechanisms modifying the far-field divergence at high operating powers. Simulations and experimental investigations of this device show a low divergence and a stable far-field along a high range of operating conditions, together with negligible astigmatism at high power.
2011 Numerical Simulation of Optoelectronic Devices, 2011
Results of theoretical and experimental studies of a photonic crystal fiber erbium doped ring las... more Results of theoretical and experimental studies of a photonic crystal fiber erbium doped ring laser are presented. Modeling parameters have been measured directly or calculated for the photonic crystal fiber analyzed. The simulations were carried out by solving in a self consistent manner the propagation and rate equations. I. INTRODUCTION Erbium doped fiber amplifiers (EDFA) and lasers (EDFL) are crucial
2011 13th International Conference on Transparent Optical Networks, 2011
We present a photonic crystal fibre based, erbium doped, polarization maintaining, near infrared,... more We present a photonic crystal fibre based, erbium doped, polarization maintaining, near infrared, fibre laser operating in a ring cavity. Stable narrow bandwidth operation of the developed fibre laser was observed in a laser ring configuration. In the paper we present the description of the laser design process and of the experimental characterisation and validation.
2009 High Power Diode Lasers and Systems Conference, 2009
A one dimensional spectral model of a self-organizing external cavity laser diode with a PR cryst... more A one dimensional spectral model of a self-organizing external cavity laser diode with a PR crystal in the external cavity was developed. The model combines the photon-carrier density coupled rate equations model and a plane wave PR crystal model. The model confirms that the self-organizing external cavity laser diode operates in a single longitudinal mode with an output power up
IEE Proceedings - Optoelectronics, 2003
ABSTRACT The properties of a tapered semiconductor laser cavity, which can be used to generate a ... more ABSTRACT The properties of a tapered semiconductor laser cavity, which can be used to generate a high-brightness optical beam, are studied. The cavity consists of a narrow straight waveguide section and a tapered power amplifier section. The influence of the input waveguide width and length, as well as of the length and taper angle of the power amplifier section, on the overall performance of the cavity are discussed. Finally, the application of beam spoilers is studied. In order to solve the wave equation, the wide-angle-beam propagation method incorporating a higher-order finite-difference scheme is applied.
A quasi-3D model has been developed with the aim of studying the different factors limiting the p... more A quasi-3D model has been developed with the aim of studying the different factors limiting the performance of high-brightness high-power tapered lasers. The model solves the complete semiconductor and thermal equations, neglecting the flow of carriers and heat along the cavity ax is, ...
Summaries of Papers Presented at the Lasers and Electro-Optics. CLEO '02. Technical Diges, 2002
... Benson, EC Larkins, School of Electrical and Electronic Engineering, University of Nottingham... more ... Benson, EC Larkins, School of Electrical and Electronic Engineering, University of Nottingham, Nottingham NG7 ZRD, UK L. Borruel, I. Esquivias, J. Arias, B. Romero ... 6:OO pm CThY6 Self-focussed Distributed Bragg Reflector Laser Diodes DA Yanson, AC Bryce, JH Marsh, Dept. ...
physica status solidi (c), 2008
Optics Communications, 2010
ABSTRACT Experimental investigation of the role of interband effects in four-wave mixing (FWM) in... more ABSTRACT Experimental investigation of the role of interband effects in four-wave mixing (FWM) in semiconductor optical amplifiers (SOAs) is reported. Carrier density pulsations (CDP) in SOAs, caused by optical wave beating, are measured in the RF domain. This gives strong experimental confirmation of the link between CDP and wave mixing, as usually assumed in theory of FWM in SOAs. The dependence of CDP amplitude on bias current and optical power is also established.
Journal of the Optical Society of America B, 2011
We describe the theoretical modeling of the external-cavity operation of a phase-locked array of ... more We describe the theoretical modeling of the external-cavity operation of a phase-locked array of diode lasers in two configurations, the self-imaging cavity based on the Talbot effect and the angular-filtering cavity. Complex filtering functions, such as the transmission or reflection of a volume Bragg grating (VBG), may be introduced in the external-cavity description. Experiments with high-brightness diode laser arrays were also conducted. The experimental results are carefully analyzed with regard to the numerical simulations, and the beneficial effect of the spectral selectivity of VBGs is demonstrated.
Optical and Quantum Electronics, 2007
Spectral performance of high power laser diodes just as important as power and beam quality • Gro... more Spectral performance of high power laser diodes just as important as power and beam quality • Growing interest in exploiting or suppressing optical nonlinearities, which appear at high optical power densities and operating frequencies • Design of devices with superior spectral or nonlinear performance requires clear understanding of optical nonlinearities Laser diode models should include optical, electrical and thermal processes
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Papers by Slawomir Sujecki