In a first, ISRO demonstrates free-space quantum communication

    • The Indian Space Research Organisation (ISRO) recently demonstrated free-space quantum communication over a distance of 300m for the first time.

    • The demonstration included live videoconferencing using quantum-key-encrypted signals.

    • This is a major achievement for unconditionally secured satellite data communication using quantum technologies.

    • A number of key technologies were developed indigenously to accomplish this major feat, which included the use of indigenously developed NAVIC receiver for time synchronization between the transmitter and receiver modules, and gimbal mechanism systems instead of bulky large-aperture telescopes for optical alignment.

    • The free-space QKD was demonstrated at Space Applications Centre (SAC), Ahmedabad, between two line-of-sight buildings within the campus.

    • The experiment was performed at night, in order to ensure that there is no interference of the direct sunlight.

    • The experiment is a major breakthrough towards ISRO’s goal of demonstrating Satellite Based Quantum Communication (SBQC), where ISRO is gearing up to demonstrate the technology between two Indian ground stations.

(The author is a trainer for Civil Services aspirants. The views expressed here are personal.)