An optical gas sensor is presented, making use of a dispersed supercontinuum source, capable of acquiring broad bandwidth spectra at ultrahigh wavelength sweep and repetition rates. Wavelength sweeps from 1100 nm to 1700 nm can be performed in 800 ns at a spectral resolution of 40 pm. This is comparable to line-widths of molecular spectra at atmospheric pressure. Quantitative measurements are p...

We investigated experimentally and theoretically an invertible fiber-type transformation from a photonic bandgap fiber into a nonideal waveguide and then into an index-guiding photonic crystal fiber via the thermo-optic effect of the fluid filled in the air holes. Such a transformation could be used to develop an in-fiber optical switch/attenuator with a high-extinction ratio of more than 35 dB...

We present a broadband single-mode bi-conical microfiber coupler (MFC) with a specifically designed transition region that effectively suppresses any higher-order modes present at the input fiber and provides efficient power splitting into the fundamental mode at the two output ports. As a practical example, single-mode 3-dB splitting operation over a broad spectral window (400 approximately 17...

We report the generation of a mid-infrared supercontinuum created by ≈7.5 ps duration pulses at 3260 nm passing through a dispersion engineered As(2)S(3) rib waveguide. The threshold for a 6.6 cm long waveguide was around 800 W and at 1700 W the spectrum extended from ≈2.9-4.2 μm and was limited on the long wavelength side by absorption in the cladding of this particular waveguide.

Background: Infrared reflectography (IRR) remains an important method to visualize underdrawing and compositional changes in paintings. Older IRR camera systems are being replaced with near-infrared cameras consisting of room temperature infrared detector arrays made out of indium gallium arsenide (InGaAs) that operate over the spectral range of ~900 to 1700 nm. Two camera types are becoming pr...

Acrylamide formation is nowadays one of the major concerns potato-processing agriculture industry. We investigate use broadband reflection spectroscopy (400–1700 nm), in combination with machine learning, to optically classify raw potatoes inducing different levels acrylamide after frying, covering concentrations between 200 ppb and 2000 ppb. Using full spectral range, we obtain a correct class...

Tellurite TeO2–TiO2–Nb2O5 thin film glasses have been produced by pulsed laser deposition. The dispersion of the real and imaginary parts of the linear refractive index has been measured in the range from 300 to 1700 nm. Films present high refractive index n=2.01 and reduced absorption k 10−4 at =1500 nm. The nonlinear third order optical susceptibility 3 has been determined at four different w...

A unique photonic crystal fiber with square and circular air holes (SC-PCF) is designed in this research. Three layers of two levels make up the cladding. The finite element approach used to simulate construction, numerical calculations are examine transmission properties S+C+L band. results reveal that SC-PCF can sustain 86 Orbital Angular Momentum (OAM) modes wavelength range 1400 nm 1700 (30...