Experimental comparison between far- and near-infrared wavelengths in free-space optical systems

The Role and Challenges of Free-space Optical Systems

“…In 1970, Nippon Electric Company (NEC) of Japan demonstrated the first full duplex FSO link by using 632.8 nm He-Ne laser to compensate the traffic data up to a length of 14 km between the Yokohama and Tamagawa [13]. Several experiments from the last decade further stimulated researchers in the field of FSO [14][15][16][17][18][19][20][21]. The link equation for FSO is given by the following equation [22]:…”

Properties of hyperbolic sinusoidal Gaussian beam propagating through strong atmospheric turbulence

“…Besides this, link performance reduces when bit rate increases 3 . An experimental study 4 states that wavelengths in far infrared region bring us higher received power when visibility in the atmosphere is low. Based upon this, we emphasize that cylindrical‐sinc Gaussian beam has off‐axis distribution along propagation axis 5 .…”

Fog and Rain Attenuation Models for the Design of Fso Links in 5g+

“…We focused on measurement campaigns with dual-or multi-wavelength transmission and collocated visibility data. Large mid-IR (8-9 µm) transmission gains over shorter wavelengths are reported by Corrigan et al [44] and Colvero et al [62].…”

“…Visibility measurements based on the contrast of a distant object are carried out by the naked eye in many cases or, sometimes, by a CCD camera [60][61] [62]. In the former case, the contrast threshold is subjective, generating further uncertainty in linking visibility measurements to the MOR and the extinction coefficient.…”

“…The extensive measurement database in [62] includes more than 100 hours of coastal fog data spreading a visibility range from 20 m to 30 km. Visibility was measured by a CCD camera placed on one side of the link and pointing to a black and white target close to the other link terminal.…”