We demonstrated a vertically coupled microring resonator (VCMRR) filter as an Add/Drop wavelength filter. However, the accuracy of center wavelength was not sufficiently high for dense wavelength division multiplexing (DWDM) systems. Thus, a UV trimming technique using a SiN (n=2.01 at λ=1.55 μm) ring core was previously developed. Although a wide center wavelength trimming range of −12.1 nm an...

Metamaterials are artificial media structured on a size scale smaller than the wavelength of external stimuli, that may provide novel tools to significantly enhance the sensitivity and resolution of the sensors. In this paper, we derive the dispersion relation of hollow cylindrical dielectric waveguide, and compute the resonant frequencies and Q factors of the corresponding Whispering-Gallery-M...

Spontaneous parametric downconversion (SPDC) can be enhanced in double-channel side-coupled microring resonator structures, generating entangled photons spatially separated in different channels. The enhancement is even more drastic in single-channel side-coupled microring resonator structures, although the generated entangled photons are not spatially separated, and it might be most interestin...

Compared to the conventional strip waveguide microring resonators, subwavelength grating (SWG) waveguide microring resonators have better sensitivity and lower detection limit due to the enhanced photon-analyte interaction. As sensors, especially biosensors, are usually used in absorptive ambient environment, it is very challenging to further improve the detection limit of the SWG ring resonato...

Silicon-on-insulator microring resonators have proven to be an excellent platform for label-free nanophotonic biosensors. The high index contrast of silicon-on-insulator allows for fabrication of micrometer-size sensors. However, it also limits the quality of the resonances by introducing an intrinsic mode-splitting. Backscattering of optical power at small waveguide variations lifts the degene...

In this letter, a passive microring-resonator-coupled semiconductor laser structure is proposed. The weakly coupled high-Q microring resonator provides a strong mode-selection filter and could considerably extend the effective cavity length of a conventional Fabry–Perot laser. The side-mode suppression ratio, the linewidth and the frequency chirp of this laser are dramatically improved comparin...

The add/drop wavelength filter is an essential component in the new-generation photonic network. Microring resonator filters using high index contrast (HIC) optical waveguides are recently attracting attention as add/drop filters owing to their compactness, functionality such as dispersion compensation, and ease of filter synthesis. In particular, the vertically coupled microring resonator (VCM...

Frequency mismatch in high-order microring-resonator filters is investigated. We demonstrate that this frequency mismatch is caused mainly by the intrafield distortion of scanning-electron-beam-lithography (SEBL) used in fabrication. The intrafield distortion of an SEBL system is measured, and a simple method is also proposed to correct this distortion. By applying this correction method, the a...

We experimentally demonstrate a spatially non-blocking five-port optical router, which is based on microring resonators tuned through the thermo-optic effect. The characteristics of the microring-resonator-based switching element are investigated to achieve balanced performances in its two output ports. The optical router is fabricated on the SOI platform using standard CMOS processing. The eff...

We demonstrate highly compact third-order silicon microring add-drop filters. The microring resonator has a small radius of 2.5 mum and a very large free spectral range of 32 nm at 1.55 mum. Experimental results show a low add-drop crosstalk of around -20 dB. Box-like channel dropping response is demonstrated, and it has a passband of ~ 1 nm (125 GHz), fast rolling-off (slope ~ 0.2 dB/GHz), hig...