Threshold Voltage Engineering in GaN-Based HFETs: A Systematic Study With the Threshold Voltage Reaching More Than 2 V
B. Döpke1, R.H. Pilny1, C. Brenner1, A. Klehr2, G. Erbert2, G. Tränkle2, J.C. Balzer1, and M.R. Hofmann1
Published in:
Opt. Express, vol. 23, no. 8, pp. 9710-9716 (2015).
Abstract:
A self-optimizing approach to intra-cavity spectral shaping of external cavity mode-locked semiconductor lasers using edge-emitting multi-section diodes is presented. An evolutionary algorithm generates spectrally resolved phase- and amplitude masks that lead to the utilization of a large part of the net gain spectrum for mode-locked operation. Using these masks as a spectral amplitude and phase filter, a bandwidth of the optical intensity spectrum of 3.7 THz is achieved and Fourier-limited pulses of 216 fs duration are generated after further external compression.
1 Lehrstuhl für Photonik und Terahertztechnologie, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
2 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, 12489 Berlin, Germany
OCIS codes:
(140.2020) Diode lasers; (140.4050) Mode-locked lasers; (140.7090) Ultrafast lasers.
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