Mitsubishi demos laser communication in satellite to satellite and to ground
Although microwave radio communication is extensively used in satellite to satellite communication and satellite to ground communication, RF radio communication faces challenges to fulfil the growing demand for bandwidth involving lot of video-content transmission. Japanese multi domain technology expert Mitsubishi Electric is developing optical communication technologies to increase the data capacity by 10 X compared to RF communication. Mitsubishi is also researching to increase the distance range of communication using optical means.
Mitsubishi Electric announced that it has successfully demonstrated laser optical frequency control using a new light source module, a key component of an envisioned high-capacity laser optical communication network to be deployed in outer space. The new module generated a 1.5-µm wavelength signal which was installed in the OPTIMAL-11 nanosatellite developed through an industry-academia collaboration and released from the International Space Station (ISS) on January 6. The use of a nanosatellite enabled the demonstration to be carried out faster and at lower cost than using a conventional large satellite.
Laser-based optical communication also enable use of relatively small and easily installed terrestrial antennas.
Mitsubishi said in its release "Satellite images are increasingly being used for purposes such as assessing conditions in post-disaster areas and the state of remote forestry resources. Existing radio-wave satellite communication systems are limited in terms of capacity, speed and distance, so new optical systems offering improved communications capabilities are required for faster and higher-resolution assessments from space."
Further details of Mitsubishi's technology as shared by its release includes:
1) World’s first optical frequency control test in space with a 1.5-µm wavelength laser light source module - Laser communication between satellites requires correction of the Doppler effect, which causes the laser optical frequency to change due to satellites moving at different speeds relative to each other. The new light source module was deployed in the world's first demonstration of a laser frequency being adjusted by up to 60 GHz in space, sufficient for Doppler effect compensation.
2) Nanosatellite developed in industry-academia collaboration enables quick, low-cost demonstration - Using a nanosatellite developed through an industry-academia collaboration project, the demonstration in outer space required only about one-third the time and one hundredth the development cost ofdemonstrations performed with large satellites.
According to ArkEdge Space Inc.'s Chief Executive Officer Takayoshi Fukuyo: “The development of nanosatellites has been gaining momentum in recent years. Nanosatellites weighing just a few kilograms can be developed and launched for low cost, so they are expected to be used in new applications, such as widespread observations of Earth using numerous satellites. The successful demonstration of the light source module aboard the OPTIMAL-1 is expected to advance the deployment of nanosatellites.” University of Fukui Associate Professor Yoshihide Aoyanagi said: “Conditions in outer space, including radiation, vacuum and temperatures, create harsh environments for equipment, so demonstrating the capability
to operate in space is crucial for the development of satellites. I hope the successful demonstration of the OPTIMAL-1 will lead to further progress in industry's use of nanosatellites.”
Mitsubishi Electric will propose the demonstrated technology for use in large-scale space development projects. Also, the company will promote nanosatellites as an important demonstration platform for space- related research and development conducted through industry-academia collaborations. Mitsubishi Electric will continue to pursue technological development aimed at the early realization of space-based laser optical communications.