Photonic matrix multiplier makes a direction-finding sensor

Area of Science:

• Photonics
• Integrated Circuits
• Optical Sensing

Background:

• Direction-of-arrival (DOA) estimation is crucial for applications like radar and optical communication.
• Traditional methods often require complex digital signal processing and bulky hardware.
• There is a need for compact, real-time DOA estimation solutions, particularly in the optical domain.

Purpose of the Study:

• To introduce a novel photonic integrated circuit (PIC) for direction-of-arrival estimation in the optical frequency band.
• To demonstrate the feasibility of using a photonic matrix-vector multiplier for DOA sensing.
• To analyze the performance trade-offs, including angular resolution and field-of-view, of the proposed PIC.

Main Methods:

• The proposed PIC samples the phasefront of an incident optical beam.
• Analog processing is performed using a photonic matrix-vector multiplier.
• The angle of arrival is mapped to an output intensity profile.

Main Results:

• Conditions for perfect DOA sensing for discrete and continuous angles were derived.
• The angular resolution and field-of-view were analyzed based on the number of ports in the photonic circuit.
• A trade-off between device complexity (unitary vs. non-unitary matrix operation) and field-of-view was identified.

Conclusions:

• The developed PIC offers a compact and efficient solution for real-time optical direction-of-arrival estimation.
• The device minimizes the need for extensive digital signal processing.
• This technology has the potential to advance optical sensing and communication systems.