SoylentNews

Arthur T Knackerbracket has found the following story:

A team of researchers from Nanjing University and Shanghai University recently demonstrated a new approach to achieving stable, high-repetition-rate laser pulses through DFWM¹, based on a novel microfiber device: a hybrid plasmonic microfiber knot resonator (HPMKR). Their open-access research appears in the latest issue of Advanced Photonics.

Given their strong evanescent field, low insertion loss, and compatibility with all-fiber optical systems, microfiber-based devices are widely used—especially for microfiber resonators. With significantly small diameter and air cladding, tapered microfibers exhibit high nonlinearity compared with common single-mode fibers (SMFs). For example, the nonlinear coefficient γ of a piece of microfiber with 2-μm diameter is calculated to be approximately 50 times that of the standard SMF (at 1550 nm).

The key device of the work, the HPMKR, includes a knot resonator formed from tapered microfiber that is attached to a glass substrate with a gilded surface and then packaged with polydimethylsiloxane (PDMS) polymer. The practical Q-factors of common microfiber resonators are well below 10⁴ but in this work, Q was optimized up to near 10⁶ experimentally. Strong surface plasmon polaritons introduced by the fine attachment of gold cause the device to exhibit prominent polarizing features; a maximum polarization-dependent loss (PDL) of 19.75 dB was achieved.

More information: Zi-xuan Ding et al. All-fiber ultrafast laser generating gigahertz-rate pulses based on a hybrid plasmonic microfiber resonator, Advanced Photonics (2020). DOI: 10.1117/1.AP.2.2.026002

1. dissipative four-wave-mixing

Original Submission