The mission of Episensors is to develop, produce, and sell high-performance, low cost infrared cameras including HgCdTe-based extended short wavelength infrared (eSWIR) cameras. Episensors is currently marketing the Night SWEEP family of infrared cameras.
Infrared radiation consists of wavelengths in the 0.75 µm - 12.0 µm region of the electromagnetic spectrum. This region is divided into four detection bands: near infrared (NIR, 0.75 µm - 1.0 µm), short-wave infrared (SWIR, 1.0 µm - 3.0 µm), mid-wave infrared (MWIR, 3.0 µm - 5.0 µm), and long-wave infrared (LWIR, 8.0 µm - 12.0 µm). Conventional commercial SWIR cameras utilizing InGaAs detectors operate in the 1.0 µm - 1.7 µm spectral band, leaving a detection gap in the 1.7 µm - 3.0 µm band. Cameras utilizing HgCdTe focal plane arrays can operate throughout the entire SWIR spectral band and are referred to as extended short-wave infrared (eSWIR) cameras. HgCdTe-based eSWIR cameras have significantly improved performance and image quality over conventional SWIR cameras, as half of the available SWIR emission from the night sky falls within the 1.7 µm - 2.5 µm spectral band.
Light in the SWIR spectral band is visible through fog, haze, dust, light dirt and other adverse visual conditions during both day and night. SWIR light is also readily reflected or absorbed by objects, thus enabling strong contrasts and high-resolution imaging. SWIR illumination comes from the sun during the day and atmospheric nightglow at night, allowing passive night time imaging without starlight or moonlight illumination.
Many applications require imaging in a specific infrared spectral band due to the nature of objects being viewed. In spectroscopy, spectral absorption properties may dictate the use of the MWIR/LWIR band. For example, MWIR cameras are often used as detection systems for gas leaks.
In other applications, the objects of interest may span a very wide temperature range requiring intra-scene imaging of both hot and cold objects. In such cases, a high performance LWIR system would be superior to the MWIR system because of its very broad dynamic range.
Episensors™ is leveraging in-house expertise in HgCdTe and Type-II superlattice (T2SL) detector technology to reduce the size, weight and power consumption of camera systems. Our cameras, which include NS-1, NS-2, and NS-4, are capable of covering the entire infrared spectrum. Our eSWIR cameras utilize HgCdTe-based detector technology and extend the cutoff wavelength from the conventional 1.7 µm cutoff up to a 2.5 µm or 3.0 µm cutoff. Our LWIR cameras utilize HgCdTe-based detectors, while we offer both T2SL-based and HgCdTe-based MWIR focal plane arrays.