IRenergie

IRenergie, or infrared energy, denotes the portion of the electromagnetic spectrum with wavelengths longer than visible light and shorter than microwaves. In physics and engineering, infrared radiation is often associated with heat and thermal emission from objects at ordinary temperatures. The infrared range is typically divided into near infrared (about 0.75 to 1.4 μm), mid infrared (1.4 to 8 μm), and far infrared (8 to 1000 μm).

The physical basis of IRenergie lies in thermal motion and quantum transitions. According to Planck's law, every body emits infrared radiation with a spectrum that depends on temperature, with the peak shifting to shorter wavelengths as temperature rises. The total emitted power follows the Stefan–Boltzmann law, increasing with the fourth power of temperature. The energy of individual IR photons is E = h c / λ, which decreases as wavelength increases.

Generation and detection are central to IRenergie applications. Common sources include the Sun, hot surfaces, electric heaters, and infrared emitters such as LEDs and lasers designed for infrared wavelengths. Detection is accomplished by bolometers, photodiodes (for near-IR, e.g., InGaAs), and cooled detectors (e.g., InSb, HgCdTe) for mid- and far-IR. Thermal cameras convert IR radiance into visual images for inspection and monitoring, while infrared spectroscopy reveals molecular composition through characteristic absorption bands.

Interaction with matter varies across the IR range. Some materials are transparent to near-IR but opaque in mid- or far-IR. Water vapor and carbon dioxide strongly absorb IR, influencing atmospheric transmission and spectroscopy. Major applications include thermal imaging, non-contact heating, industrial drying, night vision, astronomy, and environmental sensing.

Safety considerations note that IRenergie is non-ionizing but can cause thermal injury to skin and eyes with excessive exposure, requiring appropriate shielding and protective measures.