Professor Robert Taylor: Publications

Quantum beats of free and bound excitons in GaN

Applied Physics Letters 79:8 (2001) 1097-1099

Authors:

K Kyhm, RA Taylor, JF Ryan, T Aoki, M Kuwata-Gonokami, B Beaumont, P Gibart

Abstract:

We present spectrally resolved and time-integrated four-wave mixing measurements at coherent dynamics of bound excitons in a high-quality GaN epilayer. Coherent excitation, with co-circular polarized light, of the neutral donor-bound excitons (D ⁰X) and A excitons (XA) results in quantum beats, corresponding to the energy splitting between D ⁰X and XA. The temperature-dependent dephasing rate is used to deduce the strength of the D ⁰X-acoustic-phonon interaction via the homogeneous linewidth. © 2001 American Institute of Physics.

Analysis of gain saturation in In_0.02Ga_0.98N/In_0.16Ga_0.84N multiple quantum wells

APPLIED PHYSICS LETTERS 79:21 (2001) 3434-3436

Authors:

K Kyhm, RA Taylor, JF Ryan, T Someya, Y Arakawa

Quantum beats of free and bound excitons in GaN

APPLIED PHYSICS LETTERS 79:8 (2001) 1097-1099

Authors:

K Kyhm, RA Taylor, JF Ryan, T Aoki, M Kuwata-Gonokami, B Beaumont, P Gibart

Hot carrier relaxation in GaN:LO phonon scattering and excitonic effects

Physica B: Condensed Matter 272:1-4 (1999) 402-405

Authors:

ED O'Sullivan, S Hess, RA Taylor, NJ Cain, V Roberts, JS Roberts, JF Ryan

Abstract:

Hot carrier relaxation has been studied in GaN using femtosecond time-resolved optical transmission and reflection. A non-thermal electron distribution with a pronounced `cut-off' at ELO is observed for up to approximately 3 ps after photoexcitation. Monte Carlo simulations show that this behaviour is due to a remarkably strong electron-LO phonon interaction. Excitonic effects are also pronounced, and strongly influence the dynamics.

Hot carrier relaxation in GaN : LO phonon scattering and excitonic effects

PHYSICA B 272:1-4 (1999) 402-405

Authors:

ED O'Sullivan, S Hess, RA Taylor, NJ Cain, V Roberts, JS Roberts, JF Ryan

Abstract:

Hot carrier relaxation has been studied in GaN using femtosecond time-resolved optical transmission and reflection. A non-thermal electron distribution with a pronounced "cut-off" at E-LO is observed for up to similar to 3 ps after photoexcitation. Monte Carlo simulations show that this behaviour is due to a remarkably strong electron-LO phonon interaction. Excitonic effects are also pronounced and strongly influence the dynamics. (C) 1999 Published by Elsevier Science B.V. All rights reserved.

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