Mid-infrared continuous-wave parametric amplification in chalcogenide microstructured fibers

Abstract

The persistent growth of interest in the middle infrared (MIR) is stimulating the development of sources and components. Novel waveguides and fibers for the efficient use of nonlinear effects in the MIR are being intensively studied. Highly nonlinear silica fibers have enabled record performances of highly versatile parametric processes in the telecommunication band. However, no waveguiding platforms (to our knowledge) have yet solved the trade-off among high nonlinearity, low propagation losses and dispersion in the MIR. As single waveguide designs have not yet hit this particular optimal point, only pulsed-pumped demonstrations have been carried out, hindering any application requiring narrow linewidth, continuous-wave (c.w.) operation, or signal modulation. Here, we show MIR c.w. parametric amplification in a Ge 10 As 22 Se 68 tapered fiber. Leveraging state-of-the-art fabrication techniques, we use a photonic crystal fiber (PCF) geometry combining high nonlinearity and low dispersion, while maintaining single mode and low losses in the short-wave IR and MIR. We experimentally demonstrate 5 dB signal amplification and 3 dB idler conversion efficiency using only 125 mW of pump in the 2 μm wavelength range. Our result is not only the first c.w. parametric amplification measured at 2 μm in any waveguide, but it also establishes GeAsSe PCF tapers as the most promising all-fibered, high-efficiency parametric converter for advanced applications in the MIR.

Fiber fuse in chalcogenide photonic crystal fibers

“…Parametric conversion performed at a room temperature of 7°C showed no change on retrieved dispersion. The rotation of the input lens fiber showed a hole-pitch ratio variation within 2%, in accordance with the previous measurement [19]. Thus, we conclude that the ChG vapor that traveled through the air holes was deposited on their walls, effectively shrinking the size of the air hole.…”

“…For pulsed applications, an all-fiber MIR optical parametric oscillator [16], a parametric wavelength converter [17], and an allfiber MIR supercontinuum source [18] became feasible. For CW laser applications, advances in fabrication technology now allow for amplified parametric conversion in MIR [19], power delivery [20], and integration into the silica fiber network [21]. In CW applications, power intensities have exceeded 5 MW∕cm 2 .…”

“…The ChG PCF waist has a 0.5-dB/m measured propagation loss at 1.95 μm. More details about the setup can be found in [19].…”

Mid-infrared supercontinuum generation using As2Se3 photonic crystal fiber and the impact of higher-order dispersion parameters on its supercontinuum bandwidth

“…To shift the ZDW of 1st PCF structure at 2 µm wavelength so as to overcome the large material dispersion of AsSe glass, which has a ZDW around at 7 µm, the ratio d/Λ needs to be increased at 0.8 which enhances the fabrication difficulty of that design. Xing et al [52,53] reported a small core PCF design made of GeAsSe ChG glass for parametric conversions by shifting the PCF dispersion near the 2 µm region through micro-structuring and tapering the fiber while maintaining d/Λ ratio at ∼ 0.7. It was possible to obtain the ZDW with a lower d/Λ ratio for GeAsSe material owing to its lower material dispersion as compared to AsSe glass.…”

Chalcogenide Taper and Its Nonlinear Effects and Sensing Applications

“…A chalcogenide PCF taper was proposed to increase the waveguide nonlinearity for wavelength conversion based on four-wave mixing (Le et al, 2012). Xing (Xing et al, 2017) used a 1-m-long tapered GeAsSe PCF fiber with a core diameter of 1.5 mm to achieve continuous-wave-pumped four-wave mixing by combining high nonlinearity, low dispersion, low loss, and single-mode behavior, which benefits from the engineered GeAsSe PCF structure. Figure 5 shows the schematic of the dispersion-engineered tapered GeAsSe PCF fiber.…”