An 8 m/9.6 Gbps Underwater Wireless Optical Communication System

Performance evaluation of underwater wireless optical communications links in the presence of different air bubble populations

“…Using efficient and low-cost light sources such as light-emitting diodes (LEDs) [1] and laser diodes (LD) [2] in the low absorption 400-550 nm window of the electromagnetic spectrum in seawater, UWOC can provide orders of magnitude more bandwidth and achieve much higher data rates for short and moderate ranges (<100 m) [3,4]. In UWOC links, the primary factors that degrade system performance are absorption, scattering, and turbulence.…”

6-m/10-Gbps underwater wireless red-light laser transmission system

“…An even lower BER can be derived by employing LNA and equalisers before the signal is transmitted into CSA 4,15 or using a MATLAB process of equalization before demapping.…”

“…[1][2][3][4][5] Compared with blue-laser light, the absorption rate of redlaser light in clear water is higher, resulting in a shorter transmission distance. However, red laser has a significantly wider frequency response at a much lower price and, thus, provides a considerably wider transmission bandwidth.…”

Revealing Phonon Polaritons in Hexagonal Boron Nitride by Multipulse Peak Force Infrared Microscopy

“…The implementation is conceptually similar to the improvement of the resonantly enhanced infrared nano-spectroscopy (REINS) over conventional PTIR technique in the contact mode. [14] In the new configuration, the QCL laser is triggered to emit a train of laser pulses instead of emitting a single pulse during a peak force tapping cycle. The increased number of photothermal excitation events enhances the PFIR signal.…”

“…The popular photothermal induced resonance (PTIR) technique provides a spatial resolution of 20 to 100 nm, depending on types of samples. [13,14] However, PTIR uses contact mode AFM, in which the AFM tip may scratch the sample surface during scanning, irreversibly changing the surface property. [15,16] The photo-induced force microscopy (PiFM) (and tapping mode AFM-IR, which shares a similar signal acquisition mechanism with PiFM) uses the tapping mode feedback and provides a good spatial resolution of 10 nm.…”