Efficient on-chip molecule and bio-agent detection can be achieved by accessing strong molecular absorption lines in the mid-infrared, but it requires high output power broadband mid-IR sources. Here, we report supercontinuum generation in an air-clad Si 0.6 Ge 0.4 ∕Si waveguide that emits a broad spectrum spanning from 3.0 μm to 8.5 μm. These waveguides have anomalous dispersion and low propagation loss (<0.4 dB∕cm) in the mid-IR, which leads to a supercontinuum output with a high average power of more than 10 mW on-chip. The realization of broadband mid-IR sources with high spectral brightness makes the SiGe-on-Si platform promising for a wide range of applications.

The production of a broadband supercontinuum spanning from 1.8 μm to >7.5 μm is reported which was created by pumping a chalcogenide glass waveguide with ≈320 fs pulses at 4 μm. The total power was ≈20 mW and the source brightness was > ×100 that of current synchrotrons. This source promises to be an excellent laboratory tool for infrared microspectroscopy. 2000 4000 6000 8000 -40 -30 -20 -10 0 Wavelength (nm) Relative power (dB) 3260W 1640W 815W 450W 100W

We report the characteristics of low-loss chalcogenide waveguides for sensing in the mid-infrared (MIR). The waveguides consisted of a Ge₁₁.₅As₂₄Se₆₄.₅ rib waveguide core with a 10nm fluoropolymer coating on a Ge₁₁.₅As₂₄S₆₄.₅ bottom cladding and were fabricated by thermal evaporation, photolithography and ICP plasma etching. Over most of the functional group band from 1500 to 4000 cm⁻¹ the losses were < 1 dB/cm with a minimum of 0.3 dB/cm at 2000 cm⁻¹. The basic capabilities of these waveguides for spectroscopy were demonstrated by measuring the absorption spectrum of soluble Prussian blue in Dimethyl Sulphoxide.

Davies B, "Experimental demonstration of linearly polarized 2-10 μm supercontinuum generation in a chalcogenide rib waveguide", Optics Letters 41, 5(2016) 958-961. Luther-Davies B, "High brightness 2.2-12 μm mid-infrared supercontinuum generation in a nontoxic chalcogenide step-index fiber", Journal of the American Ceramic Society, 99, 8 (2016) 2565-2568. 3.Madden S, "High Q factor chalcogenide ring resonators for cavityenhanced MIR spectroscopic sensing", Optics Express 23, 15 (2015)

The wavelength dependence of the nonlinear absorption and the third order nonlinear refraction of crystalline silicon between 2.75 mu m 5.5 mu m as well as at 1.55 mu m have been measured. It was found that at all wavelengths multi-photon and free carrier absorption can be significant. In particular nonlinear absorption can affect silicon devices designed for the mid-infrared that require strong nonlinear response, such as for the generation of a supercontinuum

This Letter reports the production of a supercontinuum extending from ≈2  μm to >10  μm generated using a chalcogenide buried rib waveguide pumped with 330 femtosecond pulses at 4.184 μm. This is, to the best of our knowledge, the broadest mid-infrared supercontinuum generated in any planar waveguide platform. Because the waveguide is birefringent, quasi-single-mode, and uses an optimized dispersion design, the supercontinuum is linearly polarized with an extinction ratio >100. Dual beam spectrophotometry is performed easily using this source.

A novel perylene diimide (PDI) derivative with typical amphiphilic character, 2, was designed and prepared. The spectroscopic studies on this compound in solution revealed the face-to-face dimeric configuration and effective pi-pi interaction between the two perylene rings. This amphiphilic PDI derivative was fabricated into highly ordered films by Langmuir-Blodgett (LB) technique and fabricated into an organic field effect transistor (OFET), which shows carrier mobility around 0.05 cm(2) V(-1) s(-1) and current modulation of 10(3). This OFET performance is much better than that of monomeric PDI 1 and can be attributed to the unique face-to-face structure of 2, which promotes the interactions between neighboring PDI ring in LB film as indicated by the pi-A isotherms and UV-vis absorption.

Metasurfaces-based flat optics, which can make use of existing foundry planar technology for high throughput production, allows the arbitrary control of the wavefront and polarization of light within sub-wavelength thick structures. So far, however, flat optics for the mid-infrared has received far less attention than devices operating at visible or near-infrared wavelengths. Here, we demonstrate polarization-insensitive, highly efficient, all-dielectric metalenses operating in the mid-infrared (MIR) around 4µm. The metalens was designed using rigorous coupled wave analysis and was based on hydrogenated amorphous silicon (-Si:H) nano-pillars supported by a MgF2 substrate. The metalenses produced close to a diffraction-limited focal spot and could resolve structures on the wavelength-scale where the focusing efficiency reached Received: ((will be filled in by the editorial staff)) Revised: ((will be filled in by the editorial staff))