Abstract
Transverse mode dynamics of a 20-μm-diameter vertical-cavity surface-emitting laser (VCSEL) undergoing gain switching by deep current modulation is studied numerically. The direct current (dc) level is set slightly below threshold and is modulated by a large alternating current (ac). The resulting optical pulse train and transverse-mode patterns are obtained numerically. The ac frequency is varied from 2.5 GHz to 10 GHz, and the ac amplitude is varied from one-half to four times that of the dc level. At high modulation frequencies, a regular pulse train is not generated unless the ac amplitude is large enough. At all modulation frequencies, the transverse spatial profile switches from single-mode to multiple-mode pattern as the ac pumping level is increased. Optical pulse widths vary in the range 5-30 ps, with the pulse width decreasing when either the frequency is increased or the ac amplitude is decreased. The numerical modeling uses an approximation form of the semiconductor Maxwell-Bloch equations. Temporal evolution of the spatial profiles of the laser (and of carrier density) is determined without any assumptions about the type or number of modes.
Original language | English (US) |
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Title of host publication | Proceedings of SPIE - The International Society for Optical Engineering |
Publisher | Society of Photo-Optical Instrumentation Engineers |
Volume | 3944 |
State | Published - 2000 |
Externally published | Yes |
Event | Physics and Simulation of Optoelectronic Devices VIII - San Jose, CA, USA Duration: Jan 24 2000 → Jan 28 2000 |
Other
Other | Physics and Simulation of Optoelectronic Devices VIII |
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City | San Jose, CA, USA |
Period | 1/24/00 → 1/28/00 |
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Condensed Matter Physics