Amar Nath Ghosh | Searcharxiv

arXiv2022

Noise in supercontinuum generated using PM and non-PM tellurite glass all-normal dispersion fibers

Intensity fluctuations in supercontinuum generation are studied in polarization-maintaining (PM) and non-PM all-normal dispersion tellurite photonic crystal fibers. Dispersive Fourier transformation is used to resolve the shot-to-shot spectra generated using 225 fs pump pulses at 1.55 μm, with experimental results well reproduced by vector and scalar numerical simulations. By comparing the relative intensity noise for the PM and non-PM cases, supported by simulations, we demonstrate the advantage of the polarization-maintaining property of the PM fibers in preserving low-noise dynamics. We associate the low-noise in the PM case with the suppression of polarization modulation instability.

physics.optics↗

arXiv2019

Nested-capillary anti-resonant silica fiber with mid-infrared transmission and low bending sensitivity at 4000 nm

We report a silica glass nested capillary anti-resonant nodeless fiber with transmission and low bending sensitivity in the mid-infrared around 4000 nm. The fiber is characterized in terms of transmission over 1700-4200 nm wavelengths, revealing a mid-infrared 3500-4200 nm transmission window, clearly observable for a 12 m long fiber. Bending loss around 4000 nm is 0.5 dB/m measured over 3 full turns with 40 mm radius, going up to 5 dB/m for full turns with 15 mm radius. Our results provide experimental evidence of hollow-core silica fibers in which nested, anti-resonant capillaries provide high bend resistance in the mid-infrared. This is obtained for a fiber with large core diameter of over 60 um relative to around 30 um-capillaries in the cladding, which motivates its application in gas fiber lasers or fiber-based mid-infrared spectroscopy of COx or NxO analytes.

physics.optics↗