Temporal Encoding to Reject Background Signals in a Low Complexity, Photon Counting Communication Link.

Area of Science:

• Optoelectronics
• Optical Communications
• Photonics

Background:

• Few-photon communication systems often require complex and power-intensive transmitters or receivers.
• High noise levels in optical communication channels necessitate robust signal detection and decoding mechanisms.
• Existing systems face limitations in spatial volume and power consumption, hindering miniaturization.

Purpose of the Study:

• To develop a self-synchronized free-space optical communication system.
• To achieve efficient data transmission using compact, low-power semiconductor devices.
• To demonstrate reliable communication in the presence of significant background noise.

Main Methods:

• Implementation of a temporal encoding method using a gallium nitride micro-light-emitting diode (micro-LED) source.
• Utilization of a silicon single photon avalanche photo-detector (SPAD) for signal reception.
• Testing the system's performance with varying received power levels and background noise conditions.

Main Results:

• Demonstrated data transmission rates up to 100 kb/s at 8.25 pW received power (27 photons per bit).
• Successful signal decoding in the presence of constant and modulated background noise exceeding signal power.
• Application as a communication channel between two nano-satellite simulator systems, highlighting low power consumption and modest electronics.

Conclusions:

• The developed system offers a simple, compact, and low-power solution for free-space optical communication.
• The temporal encoding method with micro-LEDs and SPADs is effective for few-photon level communication.
• The system's robustness to noise and low power requirements make it suitable for applications like nano-satellite communications.