The modern world has an insatiable appetite for fast communication speeds and high-capacity data transfer, improving the accessibility of information in even the most remote corners of the world. This has seen the telecommunications industry evolve from using satellite-based radio frequency (RF) communication to optical cabling and photonics. More recently, the advent of Internet protocol television (IPTV), popular streaming sites and the Internet of Things (IoT) has increased internet usage and driven a hunger for higher data bandwidths. This has forced the industry to look to space once more for the next frontier of wireless technology, with the dawn of free space optical (FSO) communication.
The new frontier with FSO
FSO communication uses optical lasers to wirelessly transmit secure information from one location to another. It does this by using a network of satellites in space, sending information as bundled laser beams that then transverse the Earth and relay information to receivers on the ground. This wireless connectivity is much easier and less disruptive to deploy than installing cables and can overcome physical barriers such as large bodies of water or infrastructure in densely populated metropolitan areas. FSO also has substantial benefits over traditional RF, as the optical carrier sends signals at much higher frequencies for enhanced transmission rates – comparable to modern fibre optic networks – boosting available bandwidth and data transfer speeds. FSO also has low power requirements, and its highly focused signals are harder to intercept than traditional RF, providing a more secure line of communication. This technology brings clear advantages to internet providers and users and is already set to propel wireless transmission into a new era of speed and bandwidth.
Overcoming signal interference
FSO requires laser beams to be perfectly aligned and delivered precisely on target over long distances. However, point-to-point FSO networks are susceptible to signal interference from sources such as atmospheric turbulence or building movements, which may throw them off target. Steering systems within communication satellites therefore need fast and accurate pointing solutions that can help to correct for drift and quickly perform realignment as needed, keeping the beam on target at all times.
Piezoelectric or electromagnetic fast steering mirrors (FSM) are an effective solution for supporting FSO systems to stabilise and target beams, as well as compensate for signal disturbances when needed. Physik Instrumente (PI) is the market and technology leader for high precision positioning technologies, and its FSM solutions provide fast, compact, accurate and high-resolution beam stabilisation for FSO applications. The company’s products have helped space exploration and terrestrial projects since the 1990s and its FSM technologies are currently in use in the Solar Orbiter – a revolutionary spacecraft launched by NASA and ESA to observe the sun – proving their pedigree of extra-terrestrial applications.
Summary
Wireless telecommunications are rapidly evolving to meet the demand for faster data transfer with higher bandwidths, leading to the inception of FSO networks. Although tech companies driving the expansion of FSO networks have set their sights on ambitious goals, it is important to get the basics of accurate and stable signalling established first. Advanced piezoelectric and electromagnetic FSM solutions – such as those engineered by PI – provide FSO device manufacturers with the speed, accuracy and repeatability of movement required for high-quality beam stabilisation, as the industry ventures further and further into space.