title: High-frequency ultrasound sensors using polymer microring resonators.
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.
authors.affiliation: Department of Electrical Engineering and Computer Science at the University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Chung-Yen
authors.initials: CY
authors.lastname: Chao
authors.forename: Shai
authors.initials: S
authors.lastname: Ashkenazi
authors.forename: Sheng-Wen
authors.initials: SW
authors.lastname: Huang
authors.forename: Matthew
authors.initials: M
authors.lastname: O'Donnell
authors.forename: L Jay
authors.initials: LJ
authors.lastname: Guo
mesh_terms: D000465:Algorithms; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation*; D011108:Polymers; D011846:Radio Waves; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods; D014732:Vibration
chemical_list: D011108:Polymers