ACOUSTO-OPTO-MECHANICAL SYSTEMS in PIEZOELECTRIC ALUMINUM NITRIDE NANOFILMS FOR RADIO FREQUENCY PHOTONICS

本研究的目的是使用片上声学和光子学来生产小型化元件，为低功率无线电接收器的合成提供非常有竞争力的方法。该方法包括开发由压电氮化铝（AlN）薄膜制成的设备，其中声光（通过弹性波调制光信号）和光机械（通过辐射压力调制机械振动）效应在受限的纳米级谐振结构中被利用。所提出的射频（RF）-光子接收器依赖于AlN压电微机械滤波器来选择输入的RF信号（机电效应）和调制光子信号（声光效应）。它还利用自持光机械振荡器的固有非线性（光机械效应）将信号下变频到基带。该建议的智力价值在于解决工程上的挑战，限制实现紧凑的RF光子接收器的基础上利用AlN薄膜中的机电，声光和光机械效应。 科学，弹性光学效应在薄氮化铝薄膜和噪声机制在纳米光机械设备将被理解。 除了直接影响无线通信之外，拟议的声光机械平台将通过实现可用于医疗应用的可见光和深紫外组件，使更广泛的光子学领域受益。同时，通过声光调制器获得的高机械位移灵敏度可以转移到惯性和压力传感器，以提高其分辨率。更广泛地说，这些研究活动所产生的知识将为低功耗分布式通信链路的合成奠定基础，并将使新一代传感器网络成为可能。

The objective of this research is to use on-chip acoustics and photonics to produce miniaturized components that offer a very competitive approach for the synthesis of low power radio receivers. The approach consists in developing devices made out of piezoelectric aluminum nitride (AlN) thin films, in which acousto-optic (modulation of optical signals via elastic waves) and opto-mechanical (modulation of mechanical vibrations via radiation pressure) effects are exploited in confined nanoscale resonant structures. The proposed radio frequency (RF)-photonic receiver relies on an AlN piezoelectric micromechanical filter to select the incoming RF signal (electromechanical effect) and modulate the photonic signal (acousto-optic effect). It also uses the intrinsic non-linearity of the self-sustained opto-mechanical oscillator (opto-mechanical effect) to down convert the signal to baseband. The intellectual merit of this proposal consists in addressing the engineering challenges that limit the realization of compact RF-photonics receivers based on exploiting electromechanical, acousto-optic and opto-mechanical effects in AlN films. Scientifically, elasto-optic effects in thin AlN films and noise mechanisms in nanoscale opto-mechanical devices will be understood. Beyond directly impacting wireless communications, the proposed acousto-opto-mechanical platform will benefit the broader field of photonics by enabling visible and deep ultraviolet components that could be employed for medical applications. Simultaneously, the high mechanical displacement sensitivity attained via acousto-optic modulators can be transferred to inertial and pressure sensors to enhance their resolution. More broadly, the knowledge generated by these research activities will set the pathway for the synthesis of low power distributed communication links and will enable new generations of sensor networks.