Reconfigurable locally resonant surface acoustic demultiplexing behavior in ZnO-based phononic crystal

Abstract

We present the design and numerical investigation of a reconfigurable and miniature locally resonant surface acoustic wave demultiplexer based on a ZnO pillar phononic crystal, for the first time. Hollow cylinder line defects are used as waveguides, due to their good structural controllability over the local resonant waveguiding frequency and bandwidth. Two local resonant surface acoustic waveguides are designed and simulated as the output channels of the demultiplexer, and the shear-horizontal wave transmission spectra are calculated for each channel individually. The designed radio frequency demultiplexing output channels support frequencies of 4.14 GHz and 4.28 GHz, with respective bandwidths of 40 MHz and 60 MHz, while their spatial separation is just about 800 nm. In order to achieve a reconfigurable output characteristic, the effect of acoustoelectric interaction in piezoelectric semiconductors is numerically simulated in this study. The acoustoelectric interaction causes an additional stiffness in ZnO that can be released by adding extra charge carriers, i.e., increasing conductivity, thus changing the effective elasticity of the ZnO structures and the guiding frequencies of the output channels. Two output frequencies show red shifts of about 100 MHz and 150 MHz by extremely increasing the conductivity of ZnO structures from 0.01 S/m to 100 S/m.

Vertical Surface Phononic Mach-Zehnder Interferometer

“…Surface acoustic wave (SAW) devices were introduced in 1965 to replace the bulky electromagnetic elements (mm-m) in radar application with their micron-sized elastic counterparts through the idea of using slow elastic phonons instead of high speed photons [1]. Since then, SAWs have been an interesting research field for a variety of devices and applications, including disparate types of sensors [2][3][4], on-chip RF filters [5], microfluidics [6], quantum technology [7], acoustoelectric and acousto-optic phenomena [8][9][10], and nonreciprocity [11][12][13]. Phononic crystals (PnC) allow the controlling the propagation characteristics of acoustic and elastic waves by manipulating dispersion in applications such as filters [14], demultiplexers [9,15,16], sensors [17,18], heat transfer [19,20], energy harvesting [20,21], and resonators [22].…”

“…Since then, SAWs have been an interesting research field for a variety of devices and applications, including disparate types of sensors [2][3][4], on-chip RF filters [5], microfluidics [6], quantum technology [7], acoustoelectric and acousto-optic phenomena [8][9][10], and nonreciprocity [11][12][13]. Phononic crystals (PnC) allow the controlling the propagation characteristics of acoustic and elastic waves by manipulating dispersion in applications such as filters [14], demultiplexers [9,15,16], sensors [17,18], heat transfer [19,20], energy harvesting [20,21], and resonators [22]. The PnCs for controlling surface elastic waves can be fabricated by holes or pillars on the surface of a substrate.…”

Ultra-sensitive gas sensor based fano resonance modes in periodic and fibonacci quasi-periodic Pt/PtS2 structures

“…In PhC periodic structures, the Fano resonance phenomenon has been studied; also it has been used in PhC structure acoustic waveguide techniques 37 . The Fano resonance used in several phononics applications includes PhC resonators 38 , waveguiding 39 , and radiation detectors 40 . Meanwhile, the Fano resonance-based periodic and quasi-periodic PhC gas sensor structures, in which a very shark resonance transmitted modes with novel sensitivity, quality factors, and figure of merit did not cover before.…”

Study on Band Gap Characteristics of Boat-Shaped Phononic Crystal

“…In recent years, theoretical and applied exploration of PCs has attracted extensive research interest due to the unique function of the band gap and has proposed a wealth of applications. Especially, it has a good application prospect in damping and noise reduction and elastic wave control, including but not li-mited to sound absorbers [2] [3], vibration isolators [4], acoustic cloaks [5] [6], filters [7], and waveguides [8]. It is generally believed that there are two mechanisms for generating band gaps in phononic crystals, namely Bragg scattering [9] and local resonance [10].…”