Multiplets generation in a Semiconductor Laser Diode Subject to Delayed Optoelectronic Feedback

A multiple-quantum-well semiconductor laser diode operating under positive optoelectronic feedback is found to generate pulsing at loop-delay frequency in the case of injection current (J) faintly below threshold (J th ). Double pulsing and gradual clustering around Jth with an increasingly higher number of pulses are noticed; indeed, the commonly known regular pulsing at natural oscillation frequency (f RO ) appears for even higher J. In summary, the experimental observations acknowledge the subsistence of three explicit regimes in the delayed laser dynamics induced by optoelectronic feedback. Two of these regimes are primarily influenced by the characteristics of the external loop or field-matter interaction. The third regime features mixed-mode dynamics.