Abstract
Polymer microring resonators are demonstrated as high-frequency, ultrasound detectors. An optical microring resonator consists of a ring waveguide closely coupled to a straight bus waveguide, serving as light input and output. Acoustic waves irradiating the ring induce strain, deforming the waveguide dimensions and changing the refractive index of the waveguide via the elasto-optic effect. These effects modify the effective refractive index of the guided mode inside the waveguide. The sharp wavelength dependence of the microring resonance can enhance the optical response to acoustic strain. Such polymer microring resonators are experimentally demonstrated in detecting broadband ultrasound pulses from a 50 MHz transducer. Measured frequency response shows that these devices have potential in high-frequency, ultrasound detection. Design guidelines for polymer microring resonators forming an ultrasound detector array are discussed.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 957-964 |
| Number of pages | 8 |
| Journal | IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control |
| Volume | 54 |
| Issue number | 5 |
| DOIs | |
| State | Published - May 2007 |
Bibliographical note
Funding Information:Manuscript received June 22, 2006; accepted December 12, 2006. This work was supported by the NIH under Grant R21 EB004933-01. C. Y. Chao and L. J. Guo are with the Department of Electrical Engineering and Computer Science at the University of Michigan, Ann Arbor, MI 48109. S. Ashkenazi, S.-W. Huang, and M. O’Donnell are with the Department of Biomedical Engineering at the University of Michigan, Ann Arbor, MI 48109 (e-mail: shaia@umich.edu). Digital Object Identifier 10.1109/TUFFC.2007.341