Photonic integrated circuit based compressive sensing radio frequency receiver using waveguide speckle.

Area of Science:

• Photonics
• Integrated Optics
• Signal Processing

Background:

• Radio-frequency (RF) signal reception often requires bulky hardware.
• Compressive sensing (CS) offers a potential solution for efficient signal acquisition.
• Photonic integrated circuits (PICs) provide a platform for miniaturization.

Purpose of the Study:

• To demonstrate a miniaturized compressive sensing (CS) receiver for radio-frequency (RF) signals.
• To utilize a novel photonic integrated circuit (PIC) for RF signal processing.
• To validate the performance of the PIC-based CS system in recovering RF signal characteristics.

Main Methods:

• Fabrication of an 11 cm PIC with a multimode speckle waveguide, 1x32 splitter, and grating coupler array.
• Modulation of incoming RF signals (2.5-4.5 GHz) onto chirped optical pulses.
• Generation of random projections for CS using optical speckle within the multimode waveguide.
• Recovery of RF signal time-varying phase and amplitude using the penalized l1-norm method.

Main Results:

• Successful recovery of two test RF signals within the 2.5-4.5 GHz bandwidth.
• Demonstration of reduced footprint compared to previous fiber-based speckle mixer systems.
• Development of novel PIC structures ('waveguide bus trombone flare', 'matched 90 degree bus bend') for analog signal routing.

Conclusions:

• The passive PIC is a critical step towards miniaturizing CS RF receivers.
• The developed PIC enables efficient RF signal reception via optical speckle and CS.
• The system shows promise for future compact and high-performance RF receiver designs.