Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.589471
Title: Dynamic behaviour of spin vertical cavity surface emitting lasers
Author: Al Seyab, Rihab Khalid Shakir
Awarding Body: University of Essex
Current Institution: University of Essex
Date of Award: 2013
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Abstract:
This research investigates the nonlinear dynamics and polarization properties of solitary and optically-injected spin-Vertical-Cavity Surface-Emitting Lasers (VCSELs). We report a first comprehensive theoretical analysis of optically-pumped spin-polarized VCSELs which combines the spin flip model (SFM) with both the Largest Lyapunov Exponent (LLE) and bifurcation analysis techniques to determine regions of stability and instability. The dependence of these regions on a wide range of fundamental device parameters is investigated and results are presented in a new form of contour maps. One aspect that this reveals is the importance of considering both the birefringence rate and the linewidth enhancement factor when engineering a device for high frequency applications. Also using the experimental characteristics of an optically pumped 1300 nm dilute nitride VCSEL to derive appropriate SFM parameters, we show very good agreement between simulation and experiment for the CW behaviour and stability. The SFM has been extended and generalized to allow for optical injection of arbitrary polarization. Measurements on conventional electrically-pumped 1550-nm VCSELs with different frequency spacing between the resonances of the orthogonal polarizations of the fundamental transverse mode have been used to estimate the model's parameters. Excellent agreement is found between experiment and theory for the stability and polarization properties of the optically-injected VCSELs. Finally, the results of theoretical investigations for optically-pumped spin- VCSELs subject to polarized optical injection have been presented. The new extended SFM is used in this study to show the effect of the optical injection on the steady-state characteristics, nonlinear dynamics and polarization of spin-VCSELs. New maps of nonlinear dynamics and output polarization have been generated using different values of device parameters and pumping power and ellipticity. Furthermore, controlling the circular polarization degree of a spin- VCSEL via the optical pumping or the external optical injection has been investigated and results from the two methods compared.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.589471  DOI: Not available
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