Realizing high transmission intensity in photonic crystal nanobeams using a side-coupling waveguide

Area of Science:

• Photonics
• Nanotechnology
• Optical Engineering

Background:

• Traditional in-line photonic crystal (PhC) nanobeam cavities face challenges in measuring low-order resonances.
• A trade-off exists between high quality (Q)-factor and high transmission intensity in conventional PhC nanobeam designs.
• High mirror strength unit cells in in-line configurations can severely limit transmitted light intensity.

Purpose of the Study:

• To investigate side-coupled PhC nanobeam cavities as a solution to overcome measurement challenges.
• To demonstrate the effectiveness of side-coupling for achieving measurable resonances.
• To simplify the design of high Q-factor PhC nanobeams.

Main Methods:

• Utilizing side-coupling to direct light into the cavity center.
• Investigating the same PhC nanobeam in both in-line and side-coupled configurations.
• Employing only two different hole radii and uniform hole spacing for simplified design.

Main Results:

• Side-coupling enables measurable resonances where in-line configurations fail due to low transmission intensity.
• The side-coupling approach overcomes the limitations posed by high mirror strength unit cells.
• Simplified designs using two hole radii and uniform spacing achieve high Q-factor PhC nanobeams.

Conclusions:

• Side-coupled PhC nanobeam cavities offer a viable method for measuring low-order resonances.
• This technique enhances the practicality of PhC nanobeam devices by improving measurement capabilities.
• Simplified designs facilitate the fabrication of high-performance PhC nanobeams.