Abstract
Lately, wearable applications featuring photonic on-chip sensors are on the rise. Among many ways of controlling and/or modulating, the acousto-optic technique is seen to be a popular technique. This paper undertakes the study of different multilayer structures that can be fabricated for realizing an acousto-optic device, the objective being to obtain a high acousto-optic figure of merit (AOFM). By varying the thicknesses of the layers of these materials, several properties are discussed. The study shows that the multilayer thin film structure-based devices can give a high value of electromechanical coupling coefficient (k2) and a high AOFM as compared to the bulk piezoelectric/optical materials. The study is conducted to find the optimal normalised thickness of the multilayer structures with a material possessing the best optical and piezoelectric properties for fabricating acousto-optic devices. Based on simulations and studies of SAW propagation characteristics such as the electromechanical coupling coefficient (k2) and phase velocity (v), the acousto-optic figure of merit is calculated. The maximum value of the acousto-optic figure of merit achieved is higher than the AOFM of all the individual materials used in these layer structures. The suggested SAW device has potential application in wearable and small footprint acousto-optic devices and gives better results than those made with bulk piezoelectric materials.
Highlights
In the last few decades, photonic on-chip sensors have gained significant attention amongst the various attractive photonic integrated circuits (PICs) applications [1,2,3,4]
We investigated three multilayered structures A (ZnO/SiO2/Si), B (LiNbO3/SiO2/Si), and C (AlN/SiO2/Si)
To validate our finite element method (FEM) simulation method used in the structures under study, we first began by simulating the aluminium nitride (AlN)/Diamond structure, which was previously described [58]
Summary
In the last few decades, photonic on-chip sensors have gained significant attention amongst the various attractive photonic integrated circuits (PICs) applications [1,2,3,4]. Spectrometers based on AOTF technology have several appealing design characteristics Among these advantages, the most prominent ones are high spectral resolution, less rf driving power, high durability, compact size, maintenancefree functioning, lightweight and quick data gathering [9]. The most prominent ones are high spectral resolution, less rf driving power, high durability, compact size, maintenancefree functioning, lightweight and quick data gathering [9] Another important feature of AOTFs is, that they can simultaneously and individually filter a wide range of optical wavelengths by operating the acoustic transducer at various corresponding frequencies. AOTF-based spectrometers possess the potential to be incorporated into such sensors [10] To design such a device the features and design parameters (acousto-optic) of an AOTF must be taken into consideration. As they play a vital role in the miniaturization of the device [11]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call