University of Oulu

E. A. Avrutin, B. S. Ryvkin and J. T. Kostamovaara, "Asymmetric waveguide design of laser diodes for pico- and nanosecond pulse generation in the eye safe spectral range: Linear and nonlinear electromagnetic effects," 2017 Progress In Electromagnetics Research Symposium - Spring (PIERS), St. Petersburg, 2017, pp. 2237-2239. doi: 10.1109/PIERS.2017.8262122

Asymmetric waveguide design of laser diodes for pico- and nanosecond pulse generation in the eye safe spectral range : linear and nonlinear electromagnetic effects

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Author: Avrutin, E. A.1; Ryvkin, B. S.2,3; Kostamovaara, J. T.2
Organizations: 1Department of Electronics, University of York, York YO104LE, UK
2Department of Electrical and Information Engineering, University of Oulu, Oulu, Finland
3A. F. Ioffe Physico-Technical Institute, St. Petersburg 194021, Russia
Format: article
Version: accepted version
Access: open
Online Access: PDF Full Text (PDF, 0.2 MB)
Persistent link: http://urn.fi/urn:nbn:fi-fe2019082024800
Language: English
Published: Institute of Electrical and Electronics Engineers, 2017
Publish Date: 2019-08-20
Description:

Abstract

High energy optical pulse generation using semiconductor lasers has attracted significant attention recently, for applications such as high-precision laser radars, three-dimensional time imaging, spectroscopy, and lifetime studies. Depending on the resolution required, pulses of either several to several tens of nanoseconds or ~ 100 picoseconds in duration can be required. In the former case, from the laser dynamics point of view, the laser is operating in a steady state with a transient at the start of the pulse; in the latter case, the main techniques used are gain switching (pumping the laser with a current pulse of a nanosecond duration or somewhat shorter, but still significantly longer than the desired optical pulse), active or passive Q-switching (using a laser incorporating an active voltage-controlled modulator or a saturable absorber respectively), or a combination of these techniques. In our recent work (see [1,2] and references therein), we have used gain-switched Fabry-Perot asymmetric-waveguide semiconductor lasers with a large equivalent spot size dα ≫ 1 μm (d being the active layer thickness and Γα, the active layer confinement factor). A saturable absorber can be monolithically integrated within the laser cavity to facilitate high-energy afterpulse-free optical pulse emission in a broad range of injection current pulse amplitudes by combined gain- and Q-switching. Optical pulses with a peak power of about 35 W and a duration of about 80 ps at half maximum, without a substantial afterpulse structure, were achieved with a current pulse with an amplitude of just 8 A and a duration of 1.5 ns. Good quality, after pulsing-free optical pulses were observed in a broad range of elevated temperatures. It has also been shown [3] that a similarly asymmetric laser structure, with a Quantum Well active layer, is advantageous for quasi-CW operation (that is, pumped by current pulses long enough for the output power transients to die out, but short enough to avoid heating), correspondingly emitting optical pulses with a similar duration, of a few nanoseconds to hundreds of nanoseconds long.

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ISBN: 978-1-5090-6269-0
ISBN Print: 978-1-5090-6270-6
Pages: 2237 - 2239
DOI: 10.1109/PIERS.2017.8262122
OADOI: https://oadoi.org/10.1109/PIERS.2017.8262122
Host publication: 2017 Progress In Electromagnetics Research Symposium — Spring (PIERS)
Conference: Progress In Electromagnetics Research Symposium
Type of Publication: A4 Article in conference proceedings
Field of Science: 213 Electronic, automation and communications engineering, electronics
Subjects:
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