The ETHYLAS project aims at the development of an innovative breathalyzer using a laser source. This sensor will be based on an optical technique using new generation light source, emitting a wide spectral range in the mid-infrared domain. Optical gas sensors are already a part of our modern society and offer undeniable advantages over current sensors like chemical ones: sensitivity, selectivity, robustness, calibration free, accuracy, … However, precision gas sensors currently available are usually bulky, complex and have an expensive operating cost. The down-sizing of the optical gas sensors and the decrease of their cost are the main way for a full-scale deployment. Chemical breathalyzers are unreliable and do not provide a quantitative measure of alcohol content. The chemical compounds contained in these devices gradually degrade in time. The electronic models use an oxidation chemical reaction that cannot discriminate ethanol. In addition, they are easily contaminated and require regular calibration. Infrared breathalyzers are not wavelength selective despite the use of filters. They are sensitive to interferers and need to be regularly calibrated. ETHYLAS project will create a small-scale, reliable and accurate breathalyzer. It will be based on the tunable laser absorption spectroscopy in the mid-infrared domain. A widely tunable quantum cascade laser will be injected in a compact multi-pass cell to identify the ethanol molecule and measure its concentration in the exhaled air. Unlike current breathalyzer, ETHYLAS will provide an absolute concentration measurement without any calibration process.

Mid-infrared free-space absorption spectrometers have demonstrated label-free and real-time detection of multiple chemical and biological substances with an outstanding precision and versatility. However, they are bulky and high-cost, precluding their use in widespread high-volume applications. The MIR-Spec project will address these limitations by developing innovative silicon on-chip mid-infrared absorption spectroscopy sensors. The ground-breaking concept is to use subwavelength silicon nano-structures to develop a novel platform that leverages the wide transparency (up to ~8 µm wavelength) and large-volume fabrication processes of silicon, leading to significant breakthroughs in sensing applications. The MIR-Spec project is a “Projets de recherche collaborative - entreprises (PRCE)”, which gathers an academic research group (C2N), a Si foundry (STMircroelectronics) and an end-user (MirSense).

In this project we aim to demonstrate a \lambda~10 µm infrared photodetector, working at room temperature with a bandwidth exceeding 50GHz. Such performances are attainable by the heterodyne detection platform that we intend to develop entirely on the InP material system. The core of the receiver consists in a Quantum Cascade Detector (QCD) coupled to a plasmonic nano-antenna. This technology opens unprecedented perspectives for mid-IR spectroscopy and free space optics. The consortium is composed of an academic partner (IEMN), an industrial lab (III-Vlab) and a start-up company (mirSense), ideally setup for a fast transformation of scientific results into cutting-edge products.

The objective of the CalQ project is to demonstrate mid infrared atmospheric communications using a key-distribution relying on a pure deterministic process. In order to do so, the secret message will be encoded into a chaotic signal generated by a quantum cascade laser and then will be retrieved via quantum cascade detectors. Chaos is typically associated to rich and intrinsic oscillations, which can take place into a laser medium. The birth of the instabilities in a laser can lead to temporal and/or spatial chaotic dynamics, which must be distinguished from pure stochastic processes related to noise contributions. Encoded communications using diode laser chaos is a very well-known technology that has been widely used in the near infrared (telecoms) domain but that has never ever been applied to the mid infrared window. In order to make a free-space communication, the choice of the wavelength is of paramount importance that depends on the atmospheric transmission and the aerosol diffusion. Typically, wavelengths below the 8-12µm band strongly suffer from diffusion processes (clouds, fogs, etc.) while larger wavelengths get absorbed up to the microwave domain. Taking into account all these elements, it turns out that the most conducive spectral window is the 8-12 µm band. As a consequence of that, the project will perform the first ever secured transmission in this atmospheric transmission band by utilizing the chaotic dynamic outputted from a quantum cascade laser. The first observation of a chaotic dynamic in a quantum cascade laser was performed in the initial project (PhD thesis of Louise Jumpertz entirely funded by the DGA). All these elements make the CaLQ project strongly innovating. In addition to the proof of concept itself, the project will investigate/study the global problematic of the chaotic communications in the mid infrared window as well as identifying the key mechanisms and parameters. The project relies on a solid consortium with well-known experts in the different fields and having an excellent complementarity. TPT is in charge of the management of the project as well as the realization of the free-space communication system based on the chaotic regime from the quantum cascade laser. In order to do so, the two required building blocks will be developed by MIRS for the laser part and by the III-V Lab for the detection one. TAS will bring his strong expertise in the design of the chaotic communication system and in the final validation. The technology developed in the CaLQ project is of first importance for various applications both at the civil and defense levels. The results will feed the development of secured and furtive communications on landscapes without any infrastructures. If the system is enough compact and energy efficient, its deployment between airborne or space objects and the ground or terrestrial communication between two ground stations is envisioned with the view to create a secured communication network. High-speed communications are of paramount importance especially for applications requiring a fast transmission speed like between a drone and its base station.

The remote detection of gaseous compounds is a part of innovative technologies for the detection of gaseous compounds, whether it is in the civil domain for the atmospheric applications or in the field of the defense for the detection of hazardous materials. This last point is the object of one of the priorities of the Policy and of the Scientific Objectives 2011-2012 of the axis “Photonique” of the “Direction Générale de l’Armement”. This project aims to demonstrate in laboratory the performances of a heterodyne spectrometer using Quantum Cascades Lasers (QCL) emitting around 10 µm. It also has for objective to optimize these performances via the optimization of laser sources used as local oscillator of the device. The infrared heterodyne detection is a technique that was mainly developed to improve the detectivity of the infrared detectors, in particular in the window 8-12 µm. This technique was associated for a long time strictly for gas lasers and for cooled detectors. Fields of application were mainly the astrophysical and atmospheric studies. Few other applications were able to be envisaged because of the complexity of implementation and the dimensions of this type of instruments. Yet the recent progress in the field of lasers with semiconductors (such as the QCL which cover a big part of the infrared spectrum) and detectors (increase of the temperature of functioning) allows to envisage new developments and new applications for the infrared heterodyne detection, for example for the detection and the remote identification of molecules of atmospheric interest, such as pollutants. This technique is perfectly mastered by the partner 1 of the present project. The main assets of the heterodyne detection concern the spectral and directional selectivity of the instrument. Besides, this method allows obtaining a limit in terms of sensibility of the order of some ppm.m. It is applicable in the civil domain to the molecules of atmospheric interest such as ozone and carbon dioxide and for the military domain in the detection of hazardous materials. In spite of the progress of the characteristics of the QCL, their price remains at present prohibitive with only some companies in the world capable of supplying this type of device. Besides, it remains impossible to try to optimize their characteristics. Yet, the performances of the heterodyne spectrometer are intrinsically connected to the performances of the laser, in particular at the level of the noises such as phase noise and amplitude noise. The present project thus has for objectives: - - to develop QCL around 10 µm by the III-V lab (partner 2 of the project); - - to test them and to optimize them by the LPL (partner 3 of the project); - - to integrate them into a heterodyne spectrometer by the GSMA (partner 1 of the project).