16 September 2016 Nanoscale Si3N4 tuning fork cavity optomechanical sensors with high fmQm product
Author Affiliations +
There exists a tradeoff between the mechanical resonant frequency (fm) and the mechanical quality factor (Qm) of a nanomechanical transducer, which resulted in a tradeoff between the band width and sensitivity. Here, we present monolithic silicon nitride (Si3N4) cavity optomechanical transducer, in which high fm and Qm are achieved simultaneously. A nanoscale tuning fork mechanical resonator is near-field coupled with a microdisk optical resonator, allowing the displacement of mechanical resonator to be optically read out. Compared with a single beam with same length, width, and thickness, the tuning fork simultaneously increases fm and Qm by up to 1.4 and 12 times, respectively. A design enabled, on-chip stress tuning method is also demonstrated. By engineering the clamp design, we increased the stress in the tuning fork by 3 times that of the Si3N4 film. A fundamental mechanical in-plane squeezing mode with fm ≈ 29 MHz and Qm ≈ 2.2×105 is experimentally achieved in a high-stress tuning fork device, corresponding to a fmQm product of 6.35×1012 Hz. The tuning fork cavity optomechanical sensors may find applications where both temporal resolution and sensitivity are important such as atomic force microscopy.
© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Rui Zhang, Rui Zhang, Yundong Ren, Yundong Ren, Kartik Srinivasan, Kartik Srinivasan, Vladimir Aksyuk, Vladimir Aksyuk, Marcelo Davanço, Marcelo Davanço, Yuxiang Liu, Yuxiang Liu, "Nanoscale Si3N4 tuning fork cavity optomechanical sensors with high fmQm product", Proc. SPIE 9922, Optical Trapping and Optical Micromanipulation XIII, 99222X (16 September 2016); doi: 10.1117/12.2239197; https://doi.org/10.1117/12.2239197


Back to Top