0000000001234181
AUTHOR
Jean-paul Guillet
Tunable source of infrared pulses in gas-filled hollow core capillary
International audience; We report a tunable source that generates pulses in the infrared from an optical parametric amplification in a gas-filled hollow core capillary based on four-wave mixing process, in which the phase matching strongly depends on the gas pressure and the pump. In our case, we have generated pulses from 1 to 1.6 m in the sub-µJ level together with a parametric amplification in the visible.
Art Painting Testing with Terahertz Pulse and Frequency Modulated Continuous Wave
Paintings of individuals or collections undergo aging over time. The work of art restorers consists of repairing these defects using techniques that respect the history of the work. Ultraviolet, infrared and visible light and X-rays are well known techniques for analyzing these defects, but Terahertz is also increasingly used. Several works have shown that it is possible to detect hidden layers and various defects via terahertz pulses. In a previous work, we have shown that it is possible to use terahertz radiation to detect defects in the context of a restoration of a painting with a speed increase compared to time domain imaging.
Agar and Silica Gel Based Biotissue-mimicking Phantoms in THz Frequency Range
International audience
Optical parametric amplification in gas-filled hollow core capillary for the generation of tunable pulses in the infrared
International audience; Ultrashort pulses in the near-infrared (NIR) to mid-infrared (MIR) are widely used for laser matter interaction experiments, e.g. the relaxation process of carrier semiconductors and chemical dynamics at the femtosecond and attosecond time scale [1,2]. Many different approaches based on nonlinear processes or laser devices can be found to generate pulses in theses spectral ranges. Recently, four wave mixing (FWM) based parametric amplification in gas-filled hollow core capillary (HCC) has been used to create a tunable source of ultrashort pulses. For example, pulses can be generated in the visible with an energy at the 10 µJ level [4] and in the near infrared at ~1.4…
Terahertz Biomedical Imaging: From Multivariate Analysis and Detection to Material Parameter Extraction
Terahertz imaging is an interesting route for biomedical analysis. In particular, cancer imaging is a subject of study for different teams [1,2]. A work is done in Bordeaux in partnership with a hospital to do terahertz analysis of breast tissue. This work is done in reflection with time domain imaging setup with fresh samples. The aim is to accurately assess tumor margins and which could in the future allow a quick validation of the precision of the surgical procedure and know if new surgery should be performed. We have presented in a previous paper [3] the use of automatic methods of image generation with different parameters [4] in order to explore the different contrasts that exist in t…
Optical parametric amplification in gas-filled hollow-core capillary for the generation of tunable pulses in the infrared
International audience; Ultrashort pulses in the near-infrared (NIR) to mid-infrared (MIR) are widely used for laser matter interaction experiments, e.g. the relaxation process of carrier semiconductors and chemical dynamics at the femtosecond and attosecond time scale [1, 2]. Many different approaches based on nonlinear processes or laser devices can be found to generate pulses in theses spectral ranges. Recently, four wave mixing (FWM) based parametric amplification in gas-filled hollow core capillary (HCC) has been used to create a tunable source of ultrashort pulses. For example, pulses can be generated in the visible with an energy at the 10 µJ level [4] and in the near infrared at ~1.…
Hybrid simulator and method for teaching optics or for training adjustment of an optical device
The invention concerns a hybrid simulator (100) for teaching optics or for training adjustment of an optical device.According to the invention, the hybrid simulator (100) comprises at least one dummy optical component (10) physically simulating an optical device, at least one actuator device (30) for generating or simulating an adjustment of said dummy optical component (10), a sensor configured for detecting an adjustment signal representative of operating said actuator device (30), a digital processing system (90) comprising a numerical model for simulating an output numerical optical beam resulting from interaction between an input numerical optical beam and a numerical optical component…