Wednesday 28. February 2018

Promotionsvortrag Wenbin He
Good luck, Wenbin!


Title: GHz-rate harmonically mode-locked fibre laser using optoacoustic effects in photonic crystal fibre

Place: MPL, seminar room 1.500


In solid-core photonic crystal fibres (PCF), the tight confinement of both light and acoustic vibrations can highly enhance the optoacoustic interactions and give rise to the stimulated Raman-like scattering (SRLS). When inserting such PCF in a conventional mode-locked fibre laser, the strongly driven acoustic resonance of the PCF core, typically at GHz-range cut-off frequency, would effectively divide the meters-long cavity into hundreds of homogeneous time-slots. With a single pulse trapped in each time-slot, a stable high-harmonic mode-locked (HHML) laser at GHz-rate can been achieved with wideband tunability and low timing-jitter. Moreover, when combined with the unique “stretched-soliton” scheme, such laser can stably deliver sub-100-fs pulses at GHz-rate at only moderate pump powers.
In addition, since the intra-cavity pulses trapped in different time-slots are uncorrelated in such laser, the presence or absence of each pulse can be largely independent without affecting the temporal grid of the HHML state. With a specially-developed addressing-pulse technique, some intra-cavity pulses can be selectively erased, while the remaining binary pulses pattern can be stably stored for indefinitely long time, which enables an all-optical bit-storage in a fibre laser cavity.
Finally, within each time-slot of the cavity, the interplay between dispersive waves and acoustic waves can lead to formations of long-range bound-states of multiple solitons with internal spacings much larger than individual soliton durations. A diversity of long-range bound-states of solitons trapped in different time-slots have constituted a highly-ordered optical structure that is distributed throughout the entire cavity, with features that surprisingly resemble the chemical supramolecules, including configurational diversity, reversibility, structural flexibility and dynamic stability.

Tuesday 21. March 2017

MPL Newsletter


Issue No.11 of the MPL newsletter can be downloaded here.