Search results for "DWI"
showing 10 items of 529 documents
Improved All-Fiber Acousto-Optic Tunable Bandpass Filter
2017
An all-fiber acousto-optic tunable bandpass filter based on a 1.185-mm long coreless core mode blocker is reported. Experimental results demonstrate a minimal insertion loss of 1.2 dB at the optical resonant wavelength of 1527.7 nm with 3-dB optical bandwidth of 0.83 nm. The optimization of the device takes into account the attenuation of the acoustic wave and leads to an asymmetric configuration in which the coupling section is shorter than the recoupling part. Under the effect of a standing flexural wave the device can be operated as a bandpass modulator. The device exhibits a maximum modulation depth of 28%, 4 dB of insertion loss and 0.97 nm of optical bandwidth at 4.774 MHz.
Wavelength conversion from 1.3 µm to 1.5 µm in single-mode optical fibres using Raman-assisted three-wave mixing
2000
International audience; We theoretically analyse the achievement of wide-range all-optical wavelength conversion of a 1.31 µm signal to an idler wave in the 1.5 µm spectral region by Raman-assisted three-wave mixing in single-mode optical fibres. Raman-assisted three-wave mixing allows efficient conversion on a large frequency detuning bandwidth while alleviating the need for stringent phase-matching conditions.
Highly phosphorescent perfect green emitting iridium(iii) complex for application in OLEDs.
2007
A novel iridium complex, [bis-(2-phenylpyridine)(2-carboxy-4-dimethylaminopyridine)iridium(III)] (N984), was synthesized and characterized using spectroscopic and electrochemical methods; a solution processable OLED device incorporating the N984 complex displays electroluminescence spectra with a narrow bandwidth of 70 nm at half of its intensity, with colour coordinates of x = 0.322; y = 0.529 that are very close to those suggested by the PAL standard for a green emitter. Bolink, Henk, Henk.Bolink@uv.es ; Coronado Miralles, Eugenio, Eugenio.Coronado@uv.es ; Garcia Santamaria, Sonsoles Amor, Sonsoles.Garcia@uv.es
Antenna-coupled spintronic terahertz emitters driven by a 1550 nm femtosecond laser oscillator
2019
We demonstrate antenna-coupled spintronic terahertz (THz) emitters excited by 1550 nm, 90 fs laser pulses. Antennas are employed to optimize THz outcoupling and frequency coverage of ferromagnetic/nonmagnetic metallic spintronic structures. We directly compare the antenna-coupled devices to those without antennas. Using a 200 μm H-dipole antenna and an ErAs:InGaAs photoconductive receiver, we obtain a 2.42-fold larger THz peak-peak signal, a bandwidth of 4.5 THz, and an increase in the peak dynamic range (DNR) from 53 dB to 65 dB. A 25 μm slotline antenna offered 5 dB larger peak DNR and a bandwidth of 5 THz. For all measurements, we use a comparatively low laser power of 45 mW from a comme…
Flat supercontinuum generation pumped by amplified noise-like pulses from a figure-eight erbium-doped fiber laser
2017
The conditions to obtain noise-like pulses (NLPs) from a figure-eight fiber laser (F8L) and their application for supercontinuum (SC) generation in the anomalous dispersion regime are reported. The F8L is designed to remove the undesired low-intensity background radiation from pulse emission, generating NLPs with a 3 dB spectral bandwidth of 17.43 nm at the fundamental repetition frequency of 0.8 MHz. After amplification, NLPs reach a maximum average power of 9.2 mW and 123.32 nm spectral bandwidth. By controlling the amplifier pump power, flat SC generation is demonstrated through both a 800 m long spool of SMF-28 fiber and a piece of 5 m long highly nonlinear optical fiber. The results de…
Theory of parabolic pulse propagation in nonlinear dispersion decreasing optical fiber amplifiers
2008
Optical fibers ; Nonlinear optics ; Optical fiber amplifiers ; Optical amplifier ; Optical solitons ; Electromagnetic wave propagation ; Pulse propagation ;; International audience; We show that pulse spectral broadening in normally dispersive nonlinear fiber amplifiers may be enhanced by introducing a suitable dispersion tapering. We obtain an analytical dispersion profile that permits one to reduce pulse propagation in a varying dispersion fiber to the case of an equivalent fiber with constant parameters.
Generation of broadband THz transients via metallic spintronic emitters driven by 20-fs pulses at 1030 nm
2020
We explore power and bandwidth scaling for the generation of highly-temporally-confined THz transients from spintronic emitters, driven by the 250-fs and 20-fs pulses of a high-power 28-MHz Yb-based laser, spectrally centered at 1030 nm.
Mechanical Behaviour of a Green Sandwich Made of Flax Reinforced Polymer Facings and Cork Core
2015
Abstract This work investigates the flexural behavior of a composite sandwich made of flax fibers reinforced skin facings and an agglomerated cork core, to be employed as an eco-friendly solution for the making of structural components of small sailing boats. An experimental mechanical characterization of the strength and stiffness flexural behavior of the proposed sandwich is carried out, providing a comparison of performances from three implemented assembling techniques: hand-lay-up, vacuum bagging and resin infusion. Sandwich beams have been tested under three point bending (TPB) at various span lengths. A procedure is also proposed and implemented to consider the potential influence of …
Parabolic pulse generation with active or passive dispersion decreasing optical fibers
2007
International audience; We experimentally demonstrate the possibility to generate parabolic pulses via a single dispersion decreasing optical fiber with normal dispersion. We numerically and experimentally investigate the influence of the dispersion profile, and we show that a hybrid configuration combining dispersion decrease and gain has several benefits on the parabolic generated pulses.
Broadband microwave gas sensor: A coaxial design
2010
The method of gas detection by a broadband microwave gas sensor is presented in this article. The principle of this method is to use a sensitive material as substrate of a transmission coaxial line. The sensor represents an open line with an extreme surface in contact with gas. The interaction with the gas and the surface induces a dielectric variation of the substrate. From experimental results, the interaction between the sensitive material and each tested gas present a specific frequency spectrum of the reflection coefficient at the input of the line. The proposed method has the advantage of a compact size, wide bandwidth, simple structure, and capable with all sensitive materials. © 201…