The identification and remote detection of energetic materials have become a major issue of dual research, both civil and military, for the Defence and Security of populations in France, on the European continent and overseas. A strong axis of photonics research in this context is the ability to measure the unique spectral signatures of explosives or materials representing a potential threat (e.g., IED - Improvised Explosive Devices), from remote distances larger than 10 meters. Building a prototype for this purpose requires knowledge of some signatures of explosives in a particular spectral range and to transmit appropriate radiations operating in this range with high enough field intensities to interact with the target material and to collect the scattered field. Here, we propose to exploit the terahertz (THz) spectroscopy for the measurement and identification of spectra of explosives having a military interest and those of mimic products (« simulants »). The THz waves, located between the microwaves and infrared waves, are not invasive; they pass through some thin materials and have a high selectivity to the rotational and vibrational transitions of complex molecules including those having the functional groups of explosives. In recent years, many researchers have coupled intense femtosecond laser pulses to produce terahertz field amplitudes greater than the GV/m and being broadband enough (from 1 to 50 THz) to make the junction with the far- and mid-infrared region. In this extended spectral range, many " fingerprints " of explosives are expected. With the novel available high-power laser sources, their identification over long distances in air is nowadays possible. The ALTESSE project proposes an exploratory research on a new technology for emitting THz radiation by using two-color ultrashort laser sources in order to form a remote plasma rendered controllable by the focusing geometry and the optical beam parameters (short focal length or collimated propagation in filamentation regime). The detection part of our device is based on exploiting the second harmonic induced by four-wave mixing (third-order process) between the laser pump, the emitted THz field and a high-voltage electric field, then on performing the spectrum of the collected radiation. This method, called ABCD ("Air-Biased Coherent Detection "), never operated in France, can constitute a significant technological breakthrough in detection and analysis of a rich variety of explosives. To establish the proof of concept of this technology, four partners are involved in the project. A team of experts in high-performance computing (CEA, CELIA) will provide data from numerical simulations predicting the best laser configurations for the generation of THz sources created by plasma. During the first 18 months of the project, the University of Marburg (Germany) will test this new technology for laser-plasma-based THz spectroscopy of simulants detected in both transmission and reflexion geometries. The University of Bordeaux (CELIA) will test the same technology for laser wavelengths operating in the ocular safety domain. The last 18 months of the project will be devoted to install a laser source at the French-German Research Institute of Saint-Louis for the detection of solid explosives (powders, plastics and mixtures) by transmission and reflection, in an authorized area. We propose to record, interpret and complete the databases of many explosives in the THz-infrared band. The success of such a project would pave the way to a maturation stage especially dedicated to remote sensing and offer promising perspectives for the achievement of a demonstrator.