Surface Acoustic Waves-Localized Plasmon Interaction in Pillared Phononic Crystals

Periodic elastic structures, called phononic crystals, show interesting frequency domain characteristics that can greatly influence the performance of acoustic and ultrasonic devices for several applications. Phononic crystals are acoustic counterparts of the extensively-investigated photonic crystals that are made by varying material properties periodically. Here we demonstrate the existence of phononic band-gaps for surface acoustic waves (SAWs) in a half-space of two dimensional phononic crystals consisting of hexagonal (honeycomb) arrangement of air cylinders in a crystalline Silicon background with low filling fraction. A theoretical calculation of band structure for bulk wave using finite element method is also achieved and shows that there is no complete phononic band gap in the case of the low filling fraction. Fabrication of the holes in Silicon is done by optical lithography and deep Silicon dry etching. In the experimental characterization, we have used slanted finger interdigitated transducers deposited on a thin layer of Zinc oxide (sputtered on top of the phononic crystal structure to excite elastic surface waves in Silicon) to cover a wide range of frequencies. We believe this to be the first reported demonstration of phononic band-gap for SAWs in a hexagonal lattice phononic crystal at such a high frequency.

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Refraction of surface acoustic waves through 2D phononic crystals

Journal of Physics Conference Series ◽

10.1088/1742-6596/214/1/012048 ◽

2010 ◽

Vol 214 ◽

pp. 012048 ◽

Cited By ~ 2

Author(s):

J Pierre ◽

B Bonello ◽

O Boyko ◽

L Belliard

Keyword(s):

Acoustic Waves ◽

Surface Acoustic Waves ◽

Phononic Crystals

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Design and Fabrication of 2D Phononic Crystals in Surface Acoustic Wave Micro Devices

Microelectromechanical Systems ◽

10.1115/imece2005-82692 ◽

2005 ◽

Author(s):

Kebin Gu ◽

Chien-Liu Chang ◽

Jyh-Cherng Shieh

Keyword(s):

Silicon Substrate ◽

Acoustic Waves ◽

Surface Acoustic Waves ◽

Phononic Crystals ◽

Two Dimensional ◽

Central Frequency ◽

Potential Applications ◽

Specific Incident ◽

Lift Off ◽

Propagation Of Elastic Waves

In this paper, we present the design and fabrication of innovative phononic crystals integrated with two sets of interdigital (IDT) electrodes for frequency band selection of surface acoustic waves (SAW). The potential applications of this device include performance improvement of SAW micro-sensors, front-end components in RF circuitries, and directional receptions of high frequency acoustic waves. Analogous to the band-gap generated by photonic crystals, the phononic crystals, two dimensional repetitive structures composed of two different elastic materials, can prohibit the propagation of elastic waves with either specific incident angles or certain bandwidth. In this paper, the prohibited bandwidth has been verified by fabricating the phononic crystals between a micromachined SAW resonator and a receiver. Both the resonator and receiver are composed of IDT electrodes deposited and patterned on a thin piezoelectric layer. To confine the prohibited bandwidth on the order of hundred MHz, the diameter of the circular pores in phononic crystals is designed to be 6 micron and the aspect ratio of each pore is 3:1. To maximize the power transduction from IDT electrodes to SAW, the spacing between two inter-digits is one-fourth the wavelength of SAW. Specifically, the spacing ranges from 3.4 microns to 9.0 microns, depending on the central frequency. Both surface and bulk micromachining are employed and integrated to fabricate the crystals as well as SAW resonator and receiver altogether. Firstly, a 1.5-micron zinc oxide, which provides well-defined central frequency, is sputtered and patterned onto silicon substrate. Second, the IDT electrodes are evaporated and patterned by lift-off technique. Then the exposed silicon substrate is etched using DRIE to generate two dimensional phononic crystals. To tune the prohibited SAW bandwidth, the crystal pores are filled with copper or nickel by electroless plating. The insertion loss of the fabricated devices is characterized and is found to agree with simulation results.

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Enhanced phonon-plasmon interaction in film-coupled dimer nanoridges mediated by surface acoustic waves.

Optics Express ◽

10.1364/oe.444430 ◽

2021 ◽

Author(s):

Adnane Noual ◽

Rock Akiki ◽

Gaetan Leveque ◽

Yan Pennec ◽

Bahram Djafari Rouhani

Keyword(s):

Acoustic Waves ◽

Surface Acoustic Waves ◽

Plasmon Interaction

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Surface Acoustic Wave Band Gaps and Phononic Structures on Thin Solid Plates

Noise Control and Acoustics ◽

10.1115/imece2005-81029 ◽

2005 ◽

Author(s):

Xinya Zhang ◽

Ted Jackson ◽

Emmanuel Lafound ◽

Pierre Deymier ◽

Jerome Vasseur

Keyword(s):

Acoustic Wave ◽

Surface Acoustic Wave ◽

Acoustic Waves ◽

Phononic Crystal ◽

Surface Acoustic Waves ◽

Phononic Crystals ◽

Band Gaps ◽

Laser Ultrasonics ◽

Thin Plates ◽

Wave Band

Novel phononic crystal structures on thin plates for material science applications in ultrasonic range (~ MHz) are described. Phononic crystals are created by a periodic arrangement of two or more materials displaying a strong contrast in their elastic properties and density. Because of the artificial periodic elastic structures of phononic crystals, there can exist frequency ranges in which waves cannot propagate, giving rise to phononic band gaps which are analogous to photonic band gaps for electromagnetic waves in the well-documented photonic crystals. In the past decades, the phononic structures and acoustic band gaps based on bulk materials have been researched in length. However few investigations have been performed on phononic structures on thin plates to form surface acoustic wave band gaps. In this presentation, we report a new approach: patterning two dimensional membranes to form phononic crystals, searching for specific acoustic transport properties and surface acoustic waves band gaps through a series of deliberate designs and experimental characterizations. The proposed phononic crystals are numerically simulated through a three-dimensional plane wave expansion (PWE) method and experimentally characterized by a laser ultrasonics instrument that has been developed in our laboratory.

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