Transient response of vertical-cavity surface-emitting lasers of different active-region diameters

Abstract

Abstract-The multimode dynamics of vertical-cavity surfaceemitting lasers with different active-region diameters was measured under subnanosecond electrical excitation (800-ps pulse duration, 100-ps risetime). The dynamics is characterized by the delayed onset of higher order modes which have a turn-on delay that is dependent on the active-region diameter and the excitation parameters. A simple model that can be used to estimate this turn-on delay for large-area devices is presented. Polarizationresolved measurements show that, under this fast excitation condition, both orthogonal polarization states are isomorphic. The influence of the observed dynamics on the relative intensity noise of these devices is also discussed.

Picosecond emission dynamics of vertical-cavity surface-emitting lasers: Spatial, spectral, and polarization-resolved characterization

“…Modeling results concerning the turn-on behavior also indicate that the laser starts to emit in low order modes due to their lower threshold, compared with higher order modes [15]. Spectrally, however, not spatially resolved experiments performed by Buccafusca et al [7], [8], [19] agree very well with the observed behavior. The set of excited modes during the first relaxation oscillation peak depends on pumping conditions, and there is little change in the relative intensity increase among the modes, indicating that during this time the threshold behavior of each mode dominates the evolution of the near-field intensity [8].…”

“…Spectrally, however, not spatially resolved experiments performed by Buccafusca et al [7], [8], [19] agree very well with the observed behavior. The set of excited modes during the first relaxation oscillation peak depends on pumping conditions, and there is little change in the relative intensity increase among the modes, indicating that during this time the threshold behavior of each mode dominates the evolution of the near-field intensity [8]. The appearance of higher order modes and their dynamical behavior has been experimentally shown by Giudici et al with the help of a streak camera [9].…”

“…The observation, analysis, and understanding of the spatio-temporal dynamics on picosecond timescales, associated with the multiple transverse modes, is thus not only promising for device optimization, but also allows us to gain physical insight into the underlying mechanisms and laser-matter interaction. Up to now, only spatially integrated [7], [8] and one-dimensional cuts [9] of the time-resolved dynamics of the near-field intensity exist, precluding investigations of the dynamics of the full 2-D-spatial interactions.…”

Spatio-temporal emission dynamics of VCSELs: modal competition in the turn-on behavior

“…Spectrally, however not fully spatially resolved experiments performed by Buccafusca et al 7,8,14 agree very well with the observed behavior. The set of excited modes during the first 100 ps after turn-on depends on pumping conditions, and there is little change in the relative intensity increase among the modes, indicating that during this time the threshold behavior of each mode dominates the evolution of the spectral emission properties.…”

“…Physical insight into the underlying mechanisms and laser-matter interaction determining the dynamics is desired. Until recently, mainly spatially integrated 7,8 and one-dimensional cuts 9 of the time-resolved dynamics of the near-field intensity had been published, precluding investigations of the dynamics of the full 2-D-spatial interactions.…”