We report on the experimental development of short-tapered chalcogenide-glass rods for mid-infrared supercontinuum generation. Multi-octave spectral broadening of femtosecond laser pulses is demonstrated from 1.6 to 15.6 µm in a 5-cm-long tapered Ge20Se70Te10 rod with a waist diameter of 25 µm. Despite the multimode nature of the optical waveguide used, this work clearly shows the potential of such simple post-processed rods for advancing fiber SC sources with infrared glasses, thereby unlocking new possibilities in terms of coupling efficiency, spectral coverage, and output power.
We analyzed light confinement in circular step-index cores of tellurite and silica fibers through numerical calculations and also examined crosstalk between the fundamental modes of cores in multicore fibers. Our analysis showed that tellurite fibers have a pixel density about 2.2 times higher and a brightness about 1.4 times brighter than silica fibers. As a result, tellurite multicore image fibers have the potential to provide improved resolution and brightness for near-infrared image transportation compared with silica fibers.
In this paper, we report a successful fabrication of a highly nonlinear chalcogenide all-solid hybrid microstructured optical fiber with polarization maintaining properties and a mid-infrared SC generation. Up to 4.5 × 10-4 at 10 µm of the fiber birefringence can be realized by employing a single As2Se3 core and two As2S5 rods horizontally aligned in the AsSe2 cladding. The fiber possesses a near-zero and flattened all-normal chromatic dispersion profile over the wavelength range from 5 to 10 µm. The polarization maintaining properties of the fiber is experimentally confirmed and a broadband supercontinuum spectrum from 2 to 10 µm in the mid-infrared window was experimentally demonstrated.
We successfully fabricate a transversely disordered optical fiber made of AsSe2 and As2S5 glasses for high-resolution mid-infrared image transport. By using the fabricated fiber, we experimentally observe transverse Anderson localization of mid-infrared light at the wavelength of 3 µm. Moreover, we numerically evaluate the localization in the fiber by using a cross-sectional image of the fiber.
Aiming at maintaining the chromatic dispersion properties and fiber optical parametric amplification (FOPA) performance when fiber core fluctuation occurs, we propose a buffer step-index optical fiber. The AsSe2 chalcogenide glass is employed as the core material due to its high nonlinearity and broad transmission spectrum. The calculated results in this study show that the chromatic dispersion variation due to the change of core diameter can be greatly suppressed and a continuous and very broad FOPA signal gain spectrum can be obtained and maintained by carefully controlling the core, buffer and cladding properties such as refractive index and diameters. The calculated results in this study showed that by using the proposed 3-cm-long fiber pumped at 5.02â µm, a broad signal gain bandwidth from 3 to 14â µm at about 15â dB is attainable although the fiber core diameter Dc drastically fluctuated from 2 to 5â µm and the buffer diameter Db varies from 8.9 to 9.3â µm. Moreover, when Dc varies in smaller range from 3 to 4â µm, the FOPA signal gain spectra calculated at different fixed values of Db in the range from 8.9 to 9.3â µm are highly maintained. When Db is kept at 9.0â µm and Dc varies from 3 to 4â µm, the calculated FOPA signal gain spectra at different pump wavelengths from 4.98 to 5.02â µm are also nearly identical in the wavelength range from 3 up to 13â µm.
