Double-Slot Hybrid Plasmonic Ring Resonator Used for Optical Sensors and Modulators

Photonics

Xu Sun¹  Daoxin Dai²  Lars Thylén¹ 

[1] School of Information and Communication Technology, KTH Royal Institute of Technology, 164 40, Kista, Sweden; E-Mails:;JORCEP, Joint Research Center of Photonics of the Royal Institute of Technology (Sweden) and Zhejiang University (China), Hangzhou, 310058, China; E-Mail:

关键词: integrated optics;    waveguides;    plasmonic;   

DOI  :  10.3390/photonics2041116

来源: mdpi

【 摘 要 】

An ultra-high sensitivity double-slot hybrid plasmonic (DSHP) ring resonator, used for optical sensors and modulators, is developed. Due to high index contrast, as well as plasmonic enhancement, a considerable part of the optical energy is concentrated in the narrow slots between Si and plasmonic materials (silver is used in this paper), which leads to high sensitivity to the infiltrating materials. By partial opening of the outer plasmonic circular sheet of the DSHP ring, a conventional side-coupled silicon on insulator (SOI) bus waveguide can be used. Experimental results demonstrate ultra-high sensitivity (687.5 nm/RIU) of the developed DSHP ring resonator, which is about five-times higher than for the conventional Si ring with the same geometry. Further discussions show that a very low detection limit (5.37 × 10⁻⁶ RIU) can be achieved after loaded Q factor modifications. In addition, the plasmonic metal structures offer also the way to process optical and electronic signals along the same hybrid plasmonic circuits with small capacitance (~0.275 fF) and large electric field, which leads to possible applications in compact high-efficiency electro-optic modulators, where no extra electrodes for electronic signals are required.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.