Integrated remotely tunable optical delay line for millimeter-wave beam steering fabricated in an InP generic foundry

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Millimeter-wave Technology

Background:

• Millimeter-wave (mmWave) systems require precise beam steering capabilities.
• Existing optical delay lines often face challenges with size, fabrication tolerance, and tuning complexity.
• Integrated photonics offers a path towards miniaturized and efficient optical control systems.

Purpose of the Study:

• To propose and demonstrate a compact and fabrication-tolerant integrated optical delay line.
• To enable efficient millimeter-wave beam steering and high-resolution delay generation.
• To utilize a spectrally cyclic-arrayed waveguide grating feedback loop for enhanced functionality.

Main Methods:

• Design and fabrication of an integrated optical delay line using Indium Phosphide (InP) generic foundry.
• Implementation of a spectrally cyclic-arrayed waveguide grating feedback loop.
• Experimental characterization of insertion loss and delay generation accuracy.

Main Results:

• The integrated optical delay line was successfully fabricated with a compact and tolerant architecture.
• Bi-directional operation with simplified remote tuning was achieved.
• Insertion loss was measured to be less than 6.5 dB.
• Five distinct delays ranging from 0 to 71.6 ps were generated with errors below 0.67 ps.

Conclusions:

• The proposed integrated optical delay line is a viable solution for millimeter-wave beam steering.
• The device's cyclic nature allows for cascaded operations, supporting 2D beam steering and high-resolution delay generation.
• The fabrication-tolerant design and compact size make it suitable for practical applications.