<title>History of infrared optronics in France</title>

In France, the real start of work on the applications of infrared radiations occurred around 1947 - 1948. During many years, technological research was performed in the field of detectors, optical material, modulation techniques, and a lot of measurements were made in order to acquire a better knowledge of the propagation medium and radiation of IR sources, namely those of jet engines. The birth of industrial infrared activities in France started with the Franco-German missile guidance programs: Milan, HOT, Roland and the French air to air missile seeker programs: R530, MAGIC. At these early stages of IR technologies development, it was a great technical adventure for both the governmental agencies and industry to develop: detector technology with PbS and InSb, detector cooling for 3 - 5 micrometer wavelength range, optical material transparent in the infrared, opto mechanical design, signal processing and related electronic technologies. Etablissement Jean Turck and SAT were the pioneers associated with Aerospatiale, Matra and under contracts from the French Ministry of Defence (DGA). In the 60s, the need arose to enhance night vision capability of equipment in service with the French Army. TRT was chosen by DGA to develop the first thermal imagers: LUTHER 1, 2, and 3 with an increasing number of detectors and image frequency rate. This period was also the era in which the SAT detector made rapid advance. After basic work done in the CNRS and with the support of DGA, SAT became the world leader of MCT photovoltaic detector working in the 8 to 12 micron waveband. From 1979, TRT and SAT were given the responsibility for the joint development and production of the first generation French thermal imaging modular system so-called SMT. Now, THOMSON TTD Optronique takes over the opto-electronics activities of TRT. Laser based systems were also studied for military application using YAG type laser and CO₂ laser: Laboratoire de Marcousis, CILAS, THOMSON CSF and SAT have developed during the 70s prototypes for a laser range finder, lidar, laser weapon, and target designator. The constant need to develop increasingly efficient infrared equipment led to a significant increase in the number of detector elements implying the integration of the detector and multiplexer electronic. After tests on several possible technologies at SAT, THOMSON CSF, and LETI, the work performed by these teams in 1980 was concentrated on the development of an MCT type IRCCD detector. The selection of this detector technology for the TRIGAT program led to the creation in 1986 of SOFRADIR with the pooling of the different existing expertise. Much other equipment of the first generation was created during the 80s and is now in production: IRST for naval and airborne applications; IR line scanner for airborne reconnaissance; light thermal imagers for man-portable weapons; infrared seekers for ground to air and air to air missiles; thermal sights for submarine, tank, and missile launch systems; night vision systems for flying helicopter and aircraft; air to ground attack pods for night and day operations.