Peter M. Smowton

Cardiff University

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

P. Blood

Keysight Technologies (United States)

130

Samuel Shutts

Cardiff University

A. B. Krysa

University of Sheffield

Craig P. Allford

Cardiff University

M. Hopkinson

University of Sheffield

Huiyun Liu

University College London

Huw D. Summers

Swansea University

Sara-Jayne Gillgrass

Cardiff University

Mingchu Tang

University College London

R. A. Linke

Fraunhofer Research Institution for Microsystems and Solid State Technologies

Cooperative Institutions

Cardiff University

164

Institute of Electrical and Electronics Engineers

106

Canadian Standards Association

University of Sheffield

Chinese Academy of Sciences

Engineering and Physical Sciences Research Council

Gorgias Press (United States)

University College London

University of Cambridge

University of Wales

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Low threshold InP/AlGaInP on GaAs QD laser emitting at ∼740nm

Journal of Crystal Growth (2006)

A. B. Krysa S. L. Liew Jie Lin J.S. Roberts J. Lutti

10.1016/j.jcrysgro.2006.10.087

Cite

Citations (16)

Modal gain and internal optical mode loss of a quantum dot laser

Applied Physics Letters (2000)

Eric Herrmann Peter M. Smowton Huw D. Summers J.D. Thomson M. Hopkinson

The modal gain spectra and internal optical mode loss of a semiconductor laser structure containing a single layer of InGaAs quantum dots have been measured independently and directly as a function of current density. The quantum dot gain exhibits no obvious polarization dependence. The maximum modal gain of (11±4) cm−1 obtained from the ground state of a single layer of quantum dots is in this case insufficient for lasing operation since the internal optical mode loss measured on the same sample is (11±4) cm−1. As expected laser emission is not observed from the dot ground state, but from the excited dot state or from the wetting layer depending on device length.

Icon

10.1063/1.126911

Cite

Citations (39)

Gain in p-doped quantum dot lasers

Journal of Applied Physics (2007)

Peter M. Smowton Ian Sandall H. Y. Liu M. Hopkinson

We directly measure the gain and threshold characteristics of three quantum dot laser structures that are identical except for the level of modulation doping. The maximum modal gain increases at fixed quasi-Fermi level separation as the nominal number of acceptors increases from 0 to 15 to 50 per dot. These results are consistent with a simple model where the available electrons and holes are distributed over the dot, wetting layer, and quantum well states according to Fermi-Dirac statistics. The nonradiative recombination rate at fixed quasi-Fermi level separation is also higher for the p-doped samples leading to little increase in the gain that can be achieved at a fixed current density. However, we demonstrate that in other similar samples, where the difference in the measured nonradiative recombination is less pronounced, p doping can lead to a higher modal gain at a fixed current density.

10.1063/1.2405738

Cite

Citations (39)

Femtosecond pulse generation in passively mode locked InAs quantum dot lasers

Applied Physics Letters (2013)

P. Finch P. Blood Peter M. Smowton A. Sobiesierski R. Gwilliam

Optical pulse durations of an InAs two-section passively mode-locked quantum dot laser with a proton bombarded absorber section reduce from 8.4 ps at 250 K to 290 fs at 20 K, a factor of 29, with a corresponding increase in optical bandwidth. Rate equation analysis of gain and emission spectra using rate equations suggests this is due to the very low emission rate of carriers to the wetting layer in the low temperature, random population regime which enables dots across the whole inhomogeneous distribution to act as independent oscillators.

Wetting layer

Rate equation

10.1063/1.4822433

Cite

Citations (14)

Si-based 1.3 μm InAs/GaAs QD Lasers

2022 IEEE Photonics Conference (IPC) (2022)

Huiwen Deng Junjie Yang Hui Jia Mingchu Tang Benjamin Maglio

The effects of implementing Ge and Si buffer layers on the performance of Si-based InAs/GaAs quantum dot lasers have been investigated in this paper. The laser performance has been improved significantly by utilising group-IV buffer layers.

Buffer (optical fiber)

10.1109/ipc53466.2022.9975521

Cite

Citations (1)

Deep etched distributed Bragg reflector (DBR) InP/AlGaInP quantum dot lasers

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2011)

Samuel Shutts Gareth Edwards Stella N. Elliott Peter M. Smowton A. B. Krysa

By optimising an InP/AlGaInP quantum dot size distribution a broad and relatively flat topped gain spectra can be achieved. Using the segmented contact method we measure the optical gain spectra and use this to explain the range of lasing wavelengths that can obtained by varying the grating structure of deep etched DBR lasers. We describe the optimisation of a simple single stage ICP etch process suitable for producing anisotropic microstructures in this material system and the resulting deep-etched DBR lasers. Measurements of emission wavelength made between 220 and 320 K on a ridge laser, fabricated with cleaved facets, reveals a temperature dependence on of 0.14 nm/K. DBR structures have been used to improve this behaviour, with a dependence of peak wavelength with temperature of 0.07 nm/K, over the same temperature range. Measurements on a 4 μm wide DBR ridge laser show they can be operated up to 17 nm from the peak emission of a ridge laser operating at the same current density.

Reflector (photography)

10.1117/12.876454

Cite

Citations (2)

IEEE Photonics Technology Letters publication information

IEEE Photonics Technology Letters (2014)

S. Bigo Andrew G. Kirk F Koyama Peter M. Smowton J Aitchison

10.1109/lpt.2014.2328778

Cite

Citations (0)

Novel In-plane Semiconductor Lasers VIII

Alexey Belyanin Peter M. Smowton

Source

Cite

Citations (4)

Integrated III–V semiconductor flow cytometer with capillary fill micro-fluidics

2022 IEEE Photonics Conference (IPC) (2015)

Robert J. Thomas Mark D. Holton A. Sobiesierski Sara-Jayne Gillgrass Huw D. Summers

The potential of the device is demonstrated through the results of a micro-bead counting experiment. A 0.5 μl sample volume containing 10 μm polystyrene micro-beads in Dl water is deposited into an on-chip inlet reservoir from where it flows, under capillary action, through a buried flow cell. A laser on one side of the cell is forward biased and the opposing laser is operated as a photodiode. Both are pulsed to provide sub-μs time-resolution of bead transit `events' with a 30 mV noise floor that affords a large dynamic range of over 1.2 V. After passing through the flow cell the sample fluid is drawn into a spiral patterned exit reservoir that provides sufficient pull through to sustain a continuous flow for over 30 s with flow rate of > 4mm/s.

Fluidics

Photodiode

Bead

Polystyrene

10.1109/ipcon.2015.7323580

Cite

Citations (0)

Carrier temperature and threshold current density of quantum dot lasers

Matthew Hutchings I. O’Driscoll Peter M. Smowton P. Blood

Measured carrier temperatures of quantum dots lasers, between 200 K and 400 K, are different to that of the lattice and depend on doping type. This has consequences for thresholds and device models.

Charge-carrier density

10.1109/islc.2012.6348337

Cite

Citations (1)