Slow light in mass-produced, dispersion-engineered photonic crystal ring resonators

Abstract

We present experimental results of photonic crystal ring resonators (PhCRRs) fabricated on the CMOS-compatible, silicon-on-insulator platform via 193-nm deep-UV lithography. Our dispersion-engineering design approach is compared to experimental results, showing very good agreement between theory and measurements. Specifically, we report a mean photonic band-edge wavelength of 1546.2 ± 5.8 nm, a 0.2% variation from our targeted band-edge wavelength of 1550 nm. Methods for the direct calculation of the experimental, discrete dispersion relation and extraction of intrinsic quality factors for a highly-dispersive resonator are discussed. A maximum intrinsic quality factor of ≈83,800 is reported, substantiating our design method and indicating that high-throughput optical lithography is a viable candidate for PhCRR fabrication. Finally, through comparison of the mean intrinsic quality and slowdown factors of the PhCRRs and standard ring resonators, we present evidence of an increase in light-matter interaction strength with simultaneous preservation of microcavity lifetimes.

Air-Mode Photonic Crystal Micro-Ring Resonator With Enhanced Quality Factor for Refractive Index Sensing

“…10(b). It can be seen that all the resonant modes show an even number of nodes in the mode profiles, which is due to the beating of two wave vectors [27], [28]. It should be noted that there are two resonant modes (C and D) possessing four nodes in the mode profiles.…”

Nanoslotted microring resonator for high figure of merit refractive index sensing

“…Here, the mesh accuracy in the 3D-FDTD simulation is chosen as 4, which is a good trade-off between accuracy, memory requirements and Figure 2a shows the 3D-FDTD transmission spectrum of the proposed NSMR device with the wavelength changes from 1500 to 1600 nm. Non-uniform free-spectral range (FSR) between adjacent resonances is affected by a slow-light effect [37][38][39][40]. The Q-factor of these cavities can be defined as 1/Q = P/(ω 0 U), where P is the outgoing energy, U is the electromagnetic energy localized in the cavity, ω 0 is the frequency of light around the cavity [41].…”

Photonic crystal microring resonator for label-free biosensing

“…In this work, a PhC microring resonator (PhCR) [18][19][20][21] is demonstrated as a label-free biosensor for specific molecular detection with enhanced detection sensitivity due to its strong light-matter interaction that results from the localized optical mode field profiles of the PhC structure. Since a fraction of the optical field in the PhCR is located inside the air holes that are accessible for molecular attachment, the PhCR can detect the presence of analyte both inside the holes and on the top surface.…”

“…Since a fraction of the optical field in the PhCR is located inside the air holes that are accessible for molecular attachment, the PhCR can detect the presence of analyte both inside the holes and on the top surface. Importantly, in contrast to slots and multi-hole defects that also support increased light-matter interaction for sensing, the critical dimensions of PhCRs are compatible with advanced deep ultra-violet (DUV) lithography [21,22], which could lead to the production of high-volume, low-cost lab-on-a-chip biosensors. Moreover, all of the important properties of conventional microring resonators as biosensors are preserved for PhCRs while a significant challenge for sensing high concentrations of molecules is removed.…”