Control and Generation of Localized Pulses in Passively Mode-Locked Semiconductor Lasers

Abstract

We show experimentally and theoretically that localized pulses can be generated from an electrically biased 200 µm multi-transverse mode vertical-cavity surface-emitting laser. The device is passively mode-locked using optical feedback from a distant resonant saturable absorber mirror and is operated below its threshold. We observe multistability between the non lasing (off) solution and a large variety of pulsating solutions which have a different number and arrangement of pulses per roundtrip, thus indicating that the mode-locked pulses are localized, i.e. mutually independent. We show that modulation of the bias current allows control of the number and the location of the pulses traveling within the cavity, thus suggesting that our system can be operated as an arbitrary pattern generator of mode-locked pulses.

Formation of optical supramolecular structures in a fibre laser by tailoring long-range soliton interactions

“…Precise control and long-term stabilization of multiple-soliton patterns in these systems are the key techniques for storage and transmission of optical information and manipulation of ultrafast laser fields 5,9–11,13 . While temporal tweezing of optical solitons using external modulation provides an elegant means of manipulating optical solitons in passive fibre loops 10 or semiconductor lasers 14 , the formation of self-stabilized light structures in a variety of optical systems through short-range 13,15–18 and long-range 5,19–21 interactions between optical solitons has recently attracted considerable interest.…”

Dynamics of Localized Structures in Systems with Broken Parity Symmetry

“…While this scheme leads to conventional passive mode-locking (PML) for cavity roundtrips τ shorter than the gain recovery time τ < τ g , we operate in the long cavity regime τ τ g , and for bias currents below the lasing threshold of the compound system. In this regime the PML pulses become localized, i.e they become lasing LSs [52] which can be individually addressed by an optical/electrical perturbation [53]. By denoting G (z, t) the gain and Q (z, t) the saturable absorption, the Haus equations [54] governing their dynamics reads…”

“…Experimental evidence of this phenomenon is obtained using the setup described in [52,53] and by modulating the pumping current of a VCSEL mounted in an external cavity closed by a resonant saturable absorber mirror. When the modulation frequency ν m is almost resonant with the cavity free spectral range ν c , i.e.…”

Temporal localized structures in optical resonators

“…Writing and erasure of temporal LSs is usually implemented by perturbing the system with an optical pulse injected inside the cavity, as described in Section 2.1. While addressing would be in principle feasible using optical injection, here we take advantage of the fast response of semiconductor media to pumping current modulation and we address LSs by adding electrical pulses to the laser bias [51,52]. This parameter, which is commonly used in optoelectronics for converting an electrical bit stream into an optical one at rates higher than 10 GHz [53], appears to be very convenient for LSs' applications to information processing.…”