Optical Absorption Layers for Infrared Radiation

  • Marco Schossig


Optical functional layers with high absorption have a large number of applications. Beside their use in infrared radiation (IR) detection, they can be applied to radiation cooling because good radiation absorbers are also good emitters. Another application is the thermography of electronic devices. Here, a thin black layer deposited on a heated device gives a defined emittance of the surface. In this way, the thermal profile is calibrated absolutely in temperature. However, the most noticeable application is their use in thermal infrared detectors to transform radiation into heat. Thereby, infrared absorbing layers have to meet the following demands: (i) high and spectrally homogeneous radiation absorption, (ii) very low thermal mass, (iii) high heat conductivity, (iv) good long-term stability and reproducibility of the properties and (v) their fabrication must be compatible with the detector manufacturing technology. In the past IR absorption technology had focussed on thin films whereby several solutions of optical absorption layers for infrared radiation have been proposed. The most important are: (i) ultrathin metal films, (ii) quarter-wavelength structures, (iii) highly porous metal-black coatings, and (iv) particulate-filled polymer coatings, respectively. In recent years, new opportunities for ultrathin infrared absorption layers are offered due to recent advances in nanotechnology and plasmonics research. This chapter gives an insight into established principles of infrared radiation absorption and presents two new approaches dealing with nano-structured surfaces and plasmon resonance in nanoparticles.


Metal Film Gold Nanorods Absorption Layer Thin Metal Film Thermal Detector 
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Authors and Affiliations

  1. 1.Solid-State Electronics LaboratoryTechnische Universität DresdenDresdenGermany

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