"Ideal" optical delay lines based on tailored-coupling and reflecting, coupled-resonator optical waveguides

Area of Science:

• Photonics and Optical Engineering
• Waveguide Optics
• Resonator Physics

Background:

• Optical delay lines are crucial for signal processing and buffering.
• Existing designs often suffer from dispersion and limited bandwidth.
• Coupled-Resonator Optical Waveguides (CROWs) offer potential for compact delay lines.

Purpose of the Study:

• To design "ideal" optical delay lines with constant amplitude and group delay.
• To achieve high delay-bandwidth products in optical delay lines.
• To develop efficient and dispersion-free optical amplifiers.

Main Methods:

• Utilizing reflection from coupled-resonator optical waveguides (CROWs).
• Tailoring inter-resonator coupling coefficients to decrease monotonically.
• Realizing all-pass Bessel filters.
• Deriving time-domain and field coupling coefficients for ring resonators.

Main Results:

• Achieved "ideal" optical delay lines with constant amplitude and group delay.
• Demonstrated tailored coupling coefficients compensating for group velocity dispersion.
• Reflecting CROWs exhibit a delay-bandwidth product of 0.5 per resonator.
• Proposed efficient, dispersion-free amplifiers with uniform gain and slow light.

Conclusions:

• The proposed CROW-based design offers superior performance for optical delay lines.
• This approach enables significant advancements in optical buffering and signal processing.
• The developed formalism provides a pathway for designing advanced optical components.