Fabrication and characterization of step-index tellurite fibers with varying numerical aperture for near- and mid-infrared nonlinear optics

Solid Tellurite Optical Fiber Based on Stack-and-Draw Method for Mid-Infrared Supercontinuum Generation

“…The longer wavelength pump clearly helped. The hydroxyl absorption loss of ~55 dB/m measured in our fiber is much higher than the record demonstrated in [13,14]. These results also identify the critical need for lowering OH loss.…”

“…Traditionally, tellurite fibers are made using the rod-in-tube technique, or the build-in-casting method, where customized tubes must be made for each draw [8,9,13,14,[22][23][24][25]. The stack-and-draw method of fabricating optical fibers is regularly used for photonic crystal structures [28].…”

Dispersion-Engineered Step-Index Tellurite Fibers for Mid-Infrared Coherent Supercontinuum Generation from 1.5 to 4.5 μm with Sub-Nanojoule Femtosecond Pump Pulses

“…We developed our step-index tellurite fibers for mid-IR SC studies through the built-in-casting and the rod-in tube techniques which are well described in the literature [18,27]. A compatible core/cladding glass pair was chosen based on their optical, thermal and mechanical compatibility (Table 1) for the built-in-casting process, and their suitable refractive index difference [27]. The compositions are respectively 80TeO 2 -5ZnO-10Na 2 O-5ZnF 2 (TZNF, molar fraction) and 60TeO 2 -5ZnO 20Na 2 O-15GeO 2 (TZNG).…”

“…By monitoring the total diameter of the fibre during the latter drawing, it is possible to estimate quite accurately the core size of the resulting fiber. Typically, core diameters varying between 3 and 6 µ m are obtained when the outer fiber diameter is roughly between 120 and 240 µ m. The wavelength-dependent refractive index curve for each glass can be determined with different interpolation schemes based on two-pole Sellmeier equations fitting near-IR measurements on bulk materials (more details are given in References [25,27]). The resulting refractive index curves are shown in Figure 4a.…”

“…We find that anomalous dispersion only exists for core diameters ≥ 3.25 μm. The first ZDW can be easily tuned between 1.92 and 2.35 μm, while a second ZDW is The wavelength-dependent refractive index curve for each glass can be determined with different interpolation schemes based on two-pole Sellmeier equations fitting near-IR measurements on bulk materials (more details are given in References [25,27]). The resulting refractive index curves are shown in Figure 4a.…”