Demonstration of a Tunable Microwave-Photonic Notch Filter Using Low-Loss Silicon Ring Resonators

• Published in: Journal of lightwave technology Vol. 27; no. 12; pp. 2105 - 2110
• Main Authors: Rasras, M.S., Kun-Yii Tu, Gill, D.M., Young-Kai Chen, White, A.E., Patel, S.S., Pomerene, A., Carothers, D., Beattie, J., Beals, M., Michel, J., Kimerling, L.C.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 15-06-2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Bandwidth; Channels; Circuit properties; Detection, estimation, filtering, equalization, prediction; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Foundries; Frequency; Fundamental areas of phenomenology (including applications); Information, signal and communications theory; Integrated optics; Laser optical systems: design and operation; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; microwave-photonics; Narrowband; Noise levels; notch filter; Notch filters; Notches; Nulling; Optical filters; Optical interferometry; Optical ring resonators; Optical tuning; optical waveguide components; Optics; Physics; Resonator filters; Resonators; Resonators, cavities, amplifiers, arrays, and rings; Signal and communications theory; Signal, noise; Silicon; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Tunable circuit; Multistage method; microwave-photonics; Optical waveguide components; Mach Zehnder interferometer; Transmission channel; Data transmission; ntegrated optics; Compact design; Microwave filter; Narrow band; All pass filter; Notch filter; Ring resonator; Complementary MOS technology; Tunable filter; Channel waveguide; Active filter; Reconfigurable architectures; Transmission loss; Microwave photonics; Multistage circuit; Pole zero method; Cascade connection
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2008.2007748

We present a fully tunable multistage narrowband optical pole-zero notch filter that is fabricated in a silicon complementary metal oxide semiconductor (CMOS) foundry. The filter allows for the reconfigurable and independent tuning of the center frequency, null depth, and bandwidth for one or more notches simultaneously. It is constructed using a Mach-Zehnder interferometer (MZI) with cascaded tunable all-pass filter (APF) ring resonators in its arms. Measured filter nulling response exhibits ultranarrow notch 3 dB BW of 0.6350 GHz, and nulling depth of 33 dB. This filter is compact and integrated in an area of 1.75 mm 2 . Using this device, a novel method to cancel undesired bands of 3 dB bandwidth of < 910 MHz in microwave-photonic systems is demonstrated. The ultranarrow filter response properties have been realized based on our developed low-propagation loss silicon channel waveguide and tunable ring-resonator designs. Experimentally, they yielded a loss of 0.25 dB/cm and 0.18 dB/round trip, respectively.