A novel free-space retrocommunication link

Abstract

Retrocommunication is a new technique for asymmetric free-space optical communication that has attracted interest during recent years. Novel technologies such as multiple quantum well (MQW) optical modulators and non-mechanical laser beam steering and tracking have been studied for implementation in a retrocommunication link. Large and small aperture reflective AlGaAs/GaAs MQW modulators were optimised and fabricated. The modulators exhibit high contrast ratios (from 5 to 100) and high modulation rates (up to 16 Mbit/s). A retroreceiver consisting of four large aperture MQW modulators, associated optics and drive electronics was fabricated. Nematic liquid crystal spatial light modulators have been evaluated, characterised for beam steering and tracking and implemented in a transceiver. Small area MQW modulators, used in focal plane configurations, were studied for static communication links. Results from a novel retrocommunication link utilising a retroreceiver and non-mechanical laser beam steering and tracking will be presented. Bit rates of 8 Mbit/s were observed during non-mechanical tracking of a moving retroreceiver over 100 m range. The demonstrator system was capable of transferring audio-, real-time images or bit streams. The demonstrated principles show promising features for future low weight free-space communication links. Performance calculations including requirements for a retrocommunication link using MQW modulators and non-mechanical beam steering are discussed.

Recent developments in electroabsorption modulators at Acreo Swedish ICT

“…Surface normal EAMs for free space optical (FSO) communication applications have been demonstrated in our former works and also by other research groups [15][16][17][18]. Acreo is developing state-of-the-art large aperture EAMs up to 1.4 cm x 1.4 cm according to customized specifications regarding communication data rate, extinction ratio, insertion loss and field of view (FOV), etc.…”

“…parameters. Our EAMs have been delivered to customers worldwide for FSO communication links in space, defense, civil and industrial applications [7,[16][17][18].…”

Lunar optical wireless communication and navigation network for robotic and human exploration

“…The other side of the link includes the robot with limited resources. Using MRRs for laser communication was proposed by several research groups around the world including the Navy Research Laboratory in the USA [5][6] and Swedish research institutes [7] and Israel [8].…”

Modulating Retro-Reflector Devices and Current Link Performance at the Naval Research Laboratory

“…Transmissive modulators are placed directly in front of the CCR. Reflective modulators can be used either as mirrors directing the interrogator beam onto a CCR [8], [9] or as reflective surfaces of the CCR itself [10]. The former reflective solution, however, adds size and weight; the latter requires high precision packaging.…”