Side-coupled nanoscale photonic crystal structure with high-Q and high-stability for simultaneous refractive index and temperature sensing

ABSTRACT

In this paper, we propose a single-mode double-cavity photonic crystal (PhC) sensor for simultaneous detection of ambient refractive index (RI) and temperature. L3 cavity and L4 cavity are cascaded on both sides of the photonic crystal W1 waveguide. Two 0th-order modes generated by the two cavities with Q-factors over 16,330.80 and 8358.21 are used for sensing, which have a strong constraint on photons than the higher-order modes. By simulating the refractive index and temperature of the PhC structure, the sensing matrix can realize simultaneous sensing of two parameters. The maximum crosstalk of the two cavities is very low and can increase the accuracy of the detection. And the structure shows a good fabrication tolerance considering the deviation of the hole radius. The application of the PhC to dual-parameter sensing with high accuracy is proposed, which provides an idea for dual-parameter sensing.

KEYWORDS:

• Photonic crystal
• dual parameter
• optical sensing
• side-coupled cavity

Additional information

Funding

This research was supported by NSFC [grant numbers 61372038 and 61431003], Fund of Joint Laboratory for Undersea Optical Networks.