Open AccessHighly-efficient thermally-tuned resonant optical filters
Author(s) -
J. E. Cunningham,
Ivan Shubin,
Xuezhe Zheng,
Thierry Pinguet,
Attila Mekis,
Ying Luo,
Hiren Thacker,
Guoliang Li,
Jin Yao,
Kannan Raj,
Ashok V. Krishnamoorthy
Publication year - 2010
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.019055
Subject(s) - materials science , resonator , microheater , optoelectronics , cmos , surface micromachining , silicon on insulator , optical ring resonators , optics , silicon , physics , fabrication , medicine , alternative medicine , pathology
We demonstrate spectral tunability for microphotonic add-drop filters manufactured as ring resonators in a commercial 130 nm SOI CMOS technology. The filters are provisioned with integrated heaters built in CMOS for thermal tuning. Their thermal impedance has been dramatically increased by the selective removal of the SOI handler substrate under the device footprint using a bulk silicon micromachining process. An overall ~20x increase in the tuning efficiency has been demonstrated with a 100 µm radius ring as compared to a pre-micromachined device. A total of 3.9 mW of applied tuning power shifts the filter resonant peak across one free spectral node of the device. The Q-factor of the resonator remains unchanged after the co-integration process and hence this device geometry proves to be fully CMOS compatible. Additionally, after the cointegration process our result of 2π shift with 3.9 mW power is among the best tuning performances for this class of devices. Finally, we examine scaling the tuning efficiency versus device footprint to develop a different performance criterion for an easier comparison to evaluate thermal tuning. Our criterion is defined as the unit of power to shift the device resonance by a full 2π phase shift.