Bandgap guidance in hybrid chalcogenide–silica photonic crystal fibers

Abstract

We report a hybrid chalcogenide-silica photonic crystal fiber made by pressure-assisted melt-filling of molten glass. Photonic bandgap guidance is obtained at a silica core placed centrally in a hexagonal array of continuous centimeters-long chalcogenide strands with diameters of 1.45 μm. In the passbands of the cladding, when the transmission through the silica core is very weak, the chalcogenide strands light up with distinct modal patterns corresponding to Mie resonances. In the spectral regions between these passbands, strong bandgap guidance is observed, where the silica core transmission loss is 60 dB/cm lower. The pressure-assisted fabrication approach opens up new ways of integrating sophisticated glass-based devices into optical fiber circuitry with potential applications in supercontinuum generation, magneto-optics, wavelength selective devices, and rare-earth-doped amplifiers with high gain per unit length.

Supercontinuum generation in chalcogenide-silica step-index fibers

“…2b). Finally we note that the micro-Raman spectrum of the chalcogenide glass is identical before and after pumping into the silica capillary, suggesting that the bulk properties of the glass are not affected by melt-filling [14].…”

“…Here we report SC generation from 60 fs pulses at 1550 nm in a dispersion-tuned chalcogenide-silica step-index fiber fabricated by pressure-assisted melt-filling [14][15][16] (Fig. 1a).…”

“…The maximum strand length is limited by the length of the hot zone and the filling time. After filling, the samples are cooled down while keeping the pressure constant to prevent bubble formation in the chalcogenide core resulting from glass decomposition and reboiling [14]. When the filled fiber was cleaved at room temperature the chalcogenide surface appeared rather rough and the core developed periodic cracks along its entire length, a phenomenon that we attribute to mechanical stress caused by the large difference in thermal expansion between chalcogenide and silica.…”

Growth of ZnO nanolayers inside the capillaries of photonic crystal fibres

“…Upon infiltration of the PCF air capillaries with a high refractive index medium, the coupling of light between the core and the microstructured cladding of the fibre is altered, leading to measurable distinctive features in the optical spectra. In recent years, the infiltration of PCF capillaries with high refractive index materials such as polymers [16], ferrofluids [17], and glasses [18,19], has been highlighted for the realization of novel in-fibre devices suitable for sensing applications, magnetometers, and supercontinuum generation. On a similar manner nanoparticles attached on the internal capillary walls have been used to induce plasmonic cladding structures, and plasmonic tuned fibres for sensing applications are realized following such route [20].…”

Thermally tunable bandgaps in a hybrid As2S3/silica photonic crystal fiber

“…Several research groups around the globe are working towards the development of novel tunable fiber devices by combining different advanced optical materials with PCFs, such as polymeric organosilicon compounds [12][13][14] , liquid crystals 15 , chalcogenide glasses 16,17 , etc. Recently it has been shown that even softglasses can be integrated within polymer PCFs 18 .…”