Silicon-on-Insulator Microring Add-Drop Filters With Free Spectral Ranges Over 30 nm

Purdue Univ., West Lafayette;
Journal of Lightwave Technology (Impact Factor: 2.56). 02/2008; 26(2):228-236. DOI: 10.1109/JLT.2007.911098
Source: IEEE Xplore

ABSTRACT We demonstrate highly compact optical add-drop filters based on silicon-on-insulator microring resonators. The microring resonators have a small radius of 2.5 mu m and a very large free spectral range ~ 32 nm at the 1.55 mu m communication band. The propagation loss in such small micoring resonators was experimentally determined and shown to be extremely important in designing microring add-drop filters with low add-drop crosstalk, low drop loss, and maximally flat drop passband. For box-like channel dropping responses, second-order optical add-drop filters with two coupled microring resonators are designed and demonstrated, and the simulation matches well with the experiment. Devices were patterned with electron-beam lithography. Two fabrication procedures utilizing different polarity of resists were introduced and compared, and the process with negative resist resulted in much smaller sidewall roughness of waveguides, thus reducing the propagation loss in microring resonators.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Micro ring resonator (MRR) filters based on a silicon on insulator (SOI) nanowire waveguide are fabricated by electron beam photolithography (EBL) and inductive coupled plasma (ICP) etching technology. The cross-section size of the strip waveguides is 450 × 220 nm2, and the bending radius of the micro ring is around 5 μm. The test results from the tunable filter based on a single ring show that the free spectral range (FSR) is 16.8 nm and the extinction ratio (ER) around the wavelength 1550 nm is 18.1 dB. After thermal tuning, the filter's tuning bandwidth reaches 4.8 nm with a tuning efficiency of 0.12 nm/°C Meanwhile, we fabricated and studied multi-channel filters based on a single ring and a double ring. After measurement, we drew the following conclusions: during the signal transmission of multi-channel filters, crosstalk exists mainly among different transmission channels and are fairly distinct when there are signals input to add ports.
    Journal of Semiconductors 08/2011; 32(8):084007.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present both theoretically and experimentally the existence of defect modes in side-coupled and mutually coupled microresonator arrays. The qualitative difference between the two types of defect modes is investigated. The Q factor of both defect modes for varying defect sizes is characterized, and an enhancement of similar to 30x relative to individual loaded resonators is demonstrated. The defect modes are then compared with coupled resonator-induced transparency (CRIT), indicating that the defect modes based on side-coupled microresonator arrays are actually the extension of the CRIT resonance in two-resonator structures. (C) 2012 Optical Society of America
    Journal of the Optical Society of America B 04/2012; 29(4):738-747. · 2.21 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We fabricated and theoretically investigated an add-drop filter using an on-chip whispering gallery mode (WGM) microtoroid resonator with ultra-high quality factor (Q) side coupled to two taper fibers, forming the bus and drop waveguides. The new device design incorporates silica side walls close to the microresonators which not only enable placing the coupling fibers on the same plane with respect to the microtoroid resonator but also provides mechanical stability, leading to an add-drop filter with high drop efficiency and improved robustness to environmental perturbations. We show that this new device can be thermally tuned to drop desired wavelengths from the bus without significantly affecting the drop efficiency, which is around 57%
    Journal of Lightwave Technology 04/2013; 30(21). · 2.56 Impact Factor


1 Download
Available from