Artificial micro- and nano-structure enhanced long and very long-wavelength infrared detectors

The infrared detectors own the ability to convert information carried by photons radiated by objects into electrical signals, which broadens the horizons of human beings observing the natural environment and human activities. At present, long and very long-wavelength infrared detections have many applications in atmospheric monitoring, biological spectroscopy, night vision, etc. As the demand for high-performance infrared detectors grows rapidly, it is difficult for traditional infrared detectors to arrive at performance indicators such as high response rate, high response speed, and multi-dimensional detection. The artificial structure designed based on micro- and nano-optics can be coupled with infrared photons efficiently, and control the degrees of freedom of infrared light fields such as amplitude, polarization, phase, and wavelength comprehensively. The systems integrated by infrared detectors and artificial micro- and nano-photonic structures provide additional controllable degrees of freedom for infrared detectors. And they are expected to achieve high quantum efficiency and other merits such as high response rate, excellent polarization, and wavelength selectivity. In this review paper, the research progress of the application of artificial micro- and nano-structure in the long and very long-wavelength infrared bands is presented; the advantages, disadvantages, and the application status of different mechanisms are described in detail, which include surface plasmon polaritons, localized surface plasmon, resonant cavity structure, photon-trapping structure, metalens, spoof surface plasmon, gap plasmon, and phonon polariton. In addition, the development prospect and direction of artificial micro- and nano-structure in long-wave and very long-wave infrared devices are further pointed out.