title: Optically excited nanoscale ultrasonic transducers.
abstract: In order to work at higher ultrasonic frequencies, for instance, to increase the resolution, it is necessary to fabricate smaller and higher frequency transducers. This paper presents an ultrasonic transducer capable of being made at a very small size and operated at GHz frequencies. The transducers are activated and read optically using pulsed lasers and without physical contact between the instrumentation and the transducer. This removes some of the practical impediments of traditional piezoelectric architectures (such as wiring) and allows the devices to be placed immediately on or within samples, reducing the significant effect of attenuation which is very strong at frequencies above 1 GHz. The transducers presented in this paper exploit simultaneous optical and mechanical resonances to couple the optical input into ultrasonic waves and vice versa. This paper discusses the mechanical and optical design of the devices at a modest scale (a few μm) and explores the scaling of the transducers toward the sub-micron scale. Results are presented that show how the transducers response changes depending on its local environment and how the resonant frequency shifts when the transducer is loaded by a printed protein sample.
authors.affiliation: Electrical Systems and Optics Research Division, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Smith
authors.affiliation: Electrical Systems and Optics Research Division, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom.
authors.forename: Fernando Perez
authors.initials: FP
authors.lastname: Cota
authors.affiliation: Electrical Systems and Optics Research Division, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom.
authors.forename: Leonel
authors.initials: L
authors.lastname: Marques
authors.affiliation: Electrical Systems and Optics Research Division, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom.
authors.forename: Xuesheng
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Electric and Electronic Engineering, Faculty of Architecture and Engineering, European University of Lefke, Gemikonagi, Mersin 10, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Arca
authors.affiliation: Electrical Systems and Optics Research Division, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom.
authors.forename: Kevin
authors.initials: K
authors.lastname: Webb
authors.affiliation: School of Pharmacy, University of Nottingham, United Kingdom.
authors.forename: Jonathon
authors.initials: J
authors.lastname: Aylott
authors.affiliation: Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong.
authors.forename: Micheal G
authors.initials: MG
authors.lastname: Somekh
authors.affiliation: Electrical Systems and Optics Research Division, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom.
authors.forename: Matt
authors.initials: M
authors.lastname: Clark
mesh_terms: D004867:Equipment Design; D007834:Lasers; D008962:Models, Theoretical; D036103:Nanotechnology / Q000295:instrumentation*; D061088:Photoacoustic Techniques / Q000295:instrumentation*; D012710:Serum Albumin, Bovine / Q000032:analysis; D059629:Signal-To-Noise Ratio; D014159:Transducers; D014465:Ultrasonics / Q000295:instrumentation*
chemical_list: D012710:Serum Albumin, Bovine