Infrared Detectors - New Trends

Abstract

Recent trends in infrared detectors are towards large, electronically addressed two-dimensional arrays and higher operating temperature. This will lead both to higher performance and to smaller, lighter and more affordable IR systems. Cooling requirements are the main obstacle to the more widespread use of infrared systems based on semiconductor photodetectors, particularly in the civil field. Fundamental limitations to performance of IR photodetectors are due to the statistical nature of generation-recombination processes and resulting noise. Ways to overcome the limitations are discussed including use of the optical immersion and optical resonant cavity. Finally, the progress in a mode of operation is presented, in which the thermal generation of carriers is suppressed by the use of stationary depletion of narrow gap semiconductors. The practical near room temperature narrow gap semiconductor photodetectors are reported. Competitive technologies based on Schottky barrier devices and low dimensional solids are considered briefly.

Simulations of ionization in a hot cavity surface ion source

“…16 The production of negative halogen ions was studied using also a tubular, tantalum ionizer. 17,18 The ion source with a small pellet near the extraction opening was also employed for negative ions of halogens -a variety of low-work function materials including LaB 6 , GdB 6 , Ir 5 Ce, etc., was tested. 19 Thermal ionizers are also developed as ion catchers in order to stop swift nuclear reaction products and re-emit them as slow ions.…”

Perspective on Thin Film Waveguides for on-Chip Mid-Infrared Spectroscopy of Liquid Biochemical Analytes

“…Here the sensing mechanism is based on electronic excitations due to incident IR beam [18,19]. There are few main parameters that are important when comparing the detectors: volume, weight, cost and performance.…”

“…Photonic detectors comprise photoconductive and photovoltaic detectors. Here the sensing mechanism is based on electronic excitations due to an incident IR beam. , There are few main parameters that are important when comparing the detectors: volume, weight, cost, and performance. Thermal detectors operate at room temperature and are low cost, low performance, and high volume, whereas MIR photonic detectors have high cost, high performance, and low volume and normally need cryogenic cooling for their operation.…”

Comparison of social and physical free energies on a toy model

“…The latency of the model is not clearly represented, and it is more proper to interpret the model as a representation of a transient structure. Therefore, further in the text we concentrate on the case a ≈ c. The corresponding model states resemble stationary states and the equations (4,6,7,9) are appropriate. Furthermore, the system adaptation is maximal, because there are no unused environment resources which exist for a < c, while the efficiency of use of obtained resources is not maximal in the case a > c. Aditionally, the level of consumption c is considered equal to the reference level u 0 .…”

“…Social free energy was introduced as a measure of system resources which are unused in regular, predicted functioning, but which are involved during suppression of environmentally induced dynamics changes [8]. Depending on the context, it was recognized as the combination of innovation and conformity of a collective [1 -3], profit [4], common benefit [5], availability [6], or free value of the canonical portfolio [7].…”