This will count as one of your downloads.
You will have access to both the presentation and article (if available).
In this paper, we upconvert images provided by 1.5 μm collimated continuous wave lasers illuminating resolution targets and small objects. Using a 2.7 nm wide pump spectrum at 1064 nm, we resolve 56x64 spatial elements whereas we obtained only 16x19 spatial elements with a narrow spectrum pump laser at 1064 nm with the same beam diameter and 8x8 spatial elements with a 0.5 mm thick crystal. These results are compatible with long range target recognition. A laboratory scale experiment of active imaging of diffusive objects is shown as an illustration.
An instrument was developed based on infrared backscattering spectroscopy. We realized a pulsed laser system with a fast tunability from 8 to 10 μm using an external-cavity quantum cascade laser (EC-QCL) and optical parametric amplification (OPA). The EC-QCL is tunable from 8 to 10 μm and delivers output peak powers up to 500 mW. The peak power is amplified with high gain in an orientation-patterned gallium arsenide (OP-GaAs) nonlinear crystal. We developed a pulsed fiber laser acousto-optically tunable from 1880 to 1980 nm with output peak powers up to 7 kW as pump source to realize an efficient quasi-phase matched OPA without any mechanical or thermal action onto the nonlinear crystal. Mixing the EC-QCL and the pump beams within the OP-GaAs crystal and tuning the pump wavelength enables parametric amplification of the EC-QCL from 8 to 10 μm leading to up to 120 W peak power. The output is transmitted to a target at a distance of 10 – 20 m. A receiver based on a broadband infrared detector comprises a few detector elements. A 3D data cube is registered by wavelength tuning the laser emission while recording a synchronized signal received from the target. The presentation will describe the AMURFOCAL instrument, its functional units and its principles of operation.
The project AMURFOCAL (Active Multispectral Reflection Fingerprinting of Persistent Chemical Agents) has the research topic of stand-off detection and identification of chemical warfare agents (CWAs) with amplified quantum cascade laser technology in the long-wave infrared spectral range. The project was conducted under the Joint Investment Programme (JIP) on CBRN protection funded through the European Defence Agency (EDA).
The AMURFOCAL instrument comprises a spectrally narrow tune-able light source with a broadband infrared detector and chemometric data analysis software. The light source combines an external cavity quantum cascade laser (EC-QCL) with an optical parametric amplifier (OPA) to boost the peak output power of a short laser pulse tune-able over the infrared fingerprint region. The laser beam is focused onto a target at a distance between 10 and 20 m. A 3D data cube is registered by tuning the wavelength of the laser emission while recording the received signal scattered off the target using a multi-element infrared detector. A particular chemical is identified through the extraction of its characteristic spectral fingerprint out of the measured data.
The paper describes the AMURFOCAL instrument, its functional units, and its principles of operation.
View contact details
No SPIE Account? Create one
