Piezoelectrically tuned silicon nitride ring resonator

Typical integrated optical phase tuners alter the effective index. In this paper, we explore tuning by geometric deformation. We show that tuning efficiency, V pi L, improves as the device size shrinks down to the optimal bend radius, contrary to conventional index-shift based approaches where V pi L remains constant. We demonstrate that this approach is capable of ultra-low power tuning across a full FSR in a low-confinement silicon nitride based ring resonator of 580 mu m radius. We demonstrate record performance with V-FSR = 16V, V pi L = 3 : 6 V dB, V pi L alpha = 1:1 V dB, tuning current below 10 nA, and unattenuated tuning response up to 1 MHz. We also present optimized designs for high confinement silicon nitride and silicon based platforms with radius down to 80 mu m and 45 mu m, respectively, with performance well beyond current state-of-the-art. Applications include narrow-linewidth tunable diode lasers for spectroscopy and non-linear optics, optical phased array beamforming networks for RF antennas and LIDAR, and optical filters for WDM telecommunication links. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement