Chalcogenide-glass polarization-maintaining photonic crystal fiber for mid-infrared supercontinuum generation

In this paper, we report the design and fabrication of a highly birefringent polarization-maintaining photonic crystal fiber (PM-PCF) made from chalcogenide glass, and its application to linearly-polarized supercontinuum (SC) generation in the mid-infrared region. The PM fiber was drawn using the casting method from As38Se62 glass which features a transmission window from 2 to 10 $\mu m$ and a high nonlinear index of 1.13.10$^{-17}$m$^{2}$W$^{-1}$. It has a zero-dispersion wavelength around 4.5 $\mu m$ and, at this wavelength, a large birefringence of 6.10$^{-4}$ and consequently strong polarization maintaining properties are expected. Using this fiber, we experimentally demonstrate supercontinuum generation spanning from 3.1-6.02 $\mu m$ and 3.33-5.78 $\mu m$ using femtosecond pumping at 4 $\mu m$ and 4.53 $\mu m$, respectively. We further investigate the supercontinuum bandwidth versus the input pump polarization angle and we show very good agreement with numerical simulations of the two-polarization model based on two coupled generalized nonlinear Schr\"odinger equations.Comment: 13 pages, 8 figure

Characterization of new Sb2O3-based multicomponent heavy metal oxide glasses

International audienceNew Sb2O3-based multicomponent heavy metal oxide glasses in the Sb2O3-Na2O-WO3-PbO system were prepared using a conventional melt-quenching technique. Glass formation behavior of these glasses and their thermal, physical and structural properties were investigated using X-ray diffraction (XRD), scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDS), differential scanning calorimetry (DSC), UV-Vis-NIR spectroscopy and Fourier transform infrared (FTIR) spectroscopy analyses according to the increasing PbO concentration by keeping the Sb2O3/WO3 ratio constant. Thermal analysis of the glasses were realized in terms of glass transition temperature (Tg), crystallization temperature (Tc/Tp), glass stability against crystallization (∆T), activation energy of the glass transition reaction (Eg) and fragility parameter (m). Density (ρ), molar volume (VM), oxygen molar volume (VO), oxygen packing density (OPD), refractive index, band gap energy (Eg), average cross-link density (c n), number of bonds per unit volume (nb) and Poisson's ratio (μcal) values were calculated for the interpretation of physical and structural properties of the glasses. FTIR spectra of the glasses were evaluated in terms of structural transformations on the glass network

Optical properties of alkali-antimonite glasses and purified processes for fiber drawing

International audienceWe study Antimonite glasses in the ternary systems Sb2O3-PbO-M2O (M = Li, Na, K). We have measured the density and refractive index according to the glass composition in this system. We have also measured the optical transmission in the UV-Vis and infrared range and the optical band gap. The influence of glass synthesis on extrinsic absorption has been studied. For the first time in this system, we have observed that stable glassy composition was drawn into a fiber, and the optical losses were determined in the 1-5 μm infrared region

Towards More Coherent Sources Using a Microstructured Chalcogenide Brillouin Fiber Laser

International audienceUp to 16 dB frequency noise reduction and a linewidth 8 times narrower that of the pump source is reported for the Stokes component in a compact Brillouin fiber laser made of chalcogenide microstructured fiber. Since the pump wave is not resonant in the ring cavity, an active stabilization of the laser is not primordial thus making the system simpler and cheaper. Although only a 3 metre-long microstructured chalcogenide fiber was used as gain medium, a very low laser threshold power of 6 mW was obtained for nonresonant pumping. The linewidth-narrowing effect achieved in our BFL cavity is also discussed

Relative intensity noise and frequency noise of a compact Brillouin laser made of As38Se62 suspended-core chalcogenide fiber

International audienceRelative intensity noise and frequency noise have been measured for the first time for a single-frequency Brillouin chalcogenide As38Se62 fiber laser. This is also the first demonstration of a compact suspended-core fiber Brillouin laser, which exhibits a low threshold power of 22 mW and a slope efficiency of 26% for nonresonant pumping

Brillouin fiber laser using As38Se62 suspended-core chalcogenide fiber

International audienceIn this paper, an all-fiber Brillouin laser ring cavity using a 3-m-long suspended-core chalcogenide As38Se62 fiber is reported for the first time to our knowledge. For a nonresonant ring cavity with no servo-locking, a laser threshold power of 37 mW and an efficiency of 26 % were obtained for a fiber having a core diameter of 5 μm. The linewidth of the Brillouin fiber laser and the pump laser were respectively measured to be below 4 kHz, the resolution of our autocorrelator, and 250 kHz, thus showing the linewidth-narrowing nature of the Brillouin laser. This result paves the way to compact Brillouin lasers with low threshold power and good spectral purity. A full experimental Brillouin characterization is also reported. We measured a Brillouin gain spectrum of 14.2 MHz, a Brillouin gain coefficient of 5.6x10-9 m/W and a Brillouin frequency shift of 7.95 GHz in our fiber

Preparation and investigation of high purity Ge-Te-AgI glasses for optical application

International audienceThe method for the preparation of high purity Ge-Te-AgI glasses with low content of the limiting impurities has been developed. The method includes the synthesis of GeTe4 glass using chemical distillation purification, loading AgI and GeTe4 into silica glass reactor by evaporation in all-sealed glass vacuumed system, melting the (GeTe4)100 − x(AgI)x (x = 0-20) glass into muffle rocking furnace at 850 °С, quenching the glass in water with subsequent annealing and cooling. The prepared glass samples were investigated by energy-dispersive X-ray microanalysis, DSC, FTIR-spectroscopy, Raman spectroscopy, and laser calorimetry. The high purity (GeTe4)100 − x(AgI)x (x = 0-20) glass samples are characterized by good transparency in the spectral range of 2-20 μm, glass transition temperature of 140-160 °С, Tc − Tg difference of more than 100 °С, and a very low content of the limiting impurities. Some glass compositions with AgI content between 10 and 20 at.% manifest a good thermal stability against crystallization

All-optical time-domain demultiplexing of 170.8 Gbit/s signal in chalcogenide GeAsSe microstructured fibre

International audienceWe report on four-wave-mixing-based all-optical time-domain demultiplexing of a 170.8 Gb/s signal down to 42.7 Gb/s in a chalcogenide GeAsSe microstructured fiber. The high nonlinearity of the fiber allows error-free and low power penalty operation with only 56 mW of total input average power

Linewidth-narrowing and intensity noise reduction of the 2nd order Stokes component of a low threshold Brillouin laser made of Ge10As24Se68 chalcogenide fiber

International audienceA compact second-order Stokes Brillouin fiber laser made of microstructured chalcogenide fiber is reported for the first time. This laser required very low pump power for Stokes conversion: 6 mW for first order lasing and only 30 mW for second order lasing with nonresonant pumping. We also show linewidth-narrowing as well as intensity noise reduction for both the 1st and 2nd order Stokes component when compared to that of the pump source

6 mW and 30 mW laser threshold for respectively 1st and 2nd Brillouin Stokes order in a Ge10As24Se68 chalcogenide fiber

International audienceA compact second-order Stokes Brillouin fiber laser made of microstructured chalcogenide glass is reported for the first time. This laser has very low optical pump-power threshold for Stokes conversion: 6 mW for first order and only 30 mW for second order with nonresonant pumping