Dynamics of 1.55 μm Wavelength Single-Mode Vertical-Cavity Surface-Emitting Laser Output under External Optical Injection

Abstract

We review the temporal dynamics of the laser output spectrum and polarization state of 1.55 μm wavelength single-mode (SM) vertical-cavity surface-emitting lasers (VCSELs) induced by external optical beam injection. Injection of an external continuous-wave laser beam to a gain-switched SM VCSEL near the resonance wavelength corresponding to its main polarization-mode output was critical for improvement of its laser pulse generation characteristics, such as pulse timing-jitter reduction, linewidth narrowing, pulse amplitude enhancement, and pulse width shortening. Pulse injection of pulse width shorter than the cavity photon lifetime into the SM VCSEL in the orthogonal polarization direction with respect to its main polarization mode caused temporal delay of the polarization recovery after polarization switching (PS), and its delay was found to be the minimum at an optimized bias current. Polarization-mode bistability was observed even in the laser output of an SM VCSEL of a standard circularly cylindrical shape and used for all-optical flip-flop operations with set and reset injection pulses of very low pulse energy of order of the 3.5~4.5 fJ.

Dynamics of 1550-nm VCSELs With Positive Optoelectronic Feedback: Theory and Experiments

“…Because VCSELs play the important roles in many fields, study on the nonlinear dynamics of VCSELs is particularly important and has been widely studied. Previous theoretical and experimental research studies have demonstrated that VCSELs exhibit a wide range of nonlinear dynamics under external perturbations including optical injection, optical feedback or optoelectronic feedback (OEF) [6]- [27]. For OEF, the laser output is converted into electric current through a photodetector and fed back to the laser.…”

“…Different phenomena of VCSELs subject to optical injection or optical feedback have been studied and reported in recent years. These phenomena include polarization switching (PS) and bistability [6]- [13]; injection locking [14], and [15]; nonlinear dynamics, such as regular pulsing (RP), quasiperiodic pulsing (QP), chaos [16]- [27], etc.…”