High-order micro-ring resonator with perfect transmission using symmetrical Fibonacci structures

Area of Science:

• Photonics
• Optical Engineering
• Materials Science

Background:

• Traditional periodic micro-ring resonators suffer from the coupled resonator optical waveguide (CROW) bottle effect, causing undesirable bottle-shaped distributions in high-order transmission spectra.
• This effect degrades the quality of optical filtering, particularly in the mini and major band regions, limiting device performance.

Purpose of the Study:

• To introduce a symmetrical Fibonacci micro-ring resonator (SFMR) as an alternative to traditional designs.
• To demonstrate the SFMR's ability to overcome the limitations imposed by the CROW bottle.
• To enhance the filtering quality of micro-ring resonators.

Main Methods:

• Theoretical presentation and analysis of the symmetrical Fibonacci micro-ring resonator (SFMR) design.
• Comparison of SFMR transmission spectra with those of traditional periodic micro-ring resonators.
• Investigation of resonance sharpness, transmission peak quality, and band-edge peak width variations.

Main Results:

• The SFMR design successfully eliminates the CROW bottle, resulting in significantly sharper resonances.
• Perfect transmission peaks are consistently achieved in both mini-band and major-band regions without radius or coupling modulation.
• The full width at half-maximum of the band-edge peak demonstrates a decreasing trend with increasing generation order.

Conclusions:

• The SFMR offers superior filtering quality compared to traditional periodic micro-ring resonators.
• The elimination of the CROW bottle and achievement of perfect transmission highlight the SFMR's potential for advanced optical filtering applications.
• The observed relationship between band-edge peak width and generation order provides a tunable characteristic for device design.