Nanowire Ring Embedded in a Flexible Substrate for Local Strain Detection.

Shengkun Li,Xin Li,Yuejin Zhao,Yue Qin

doi:10.3390/ma13020347

Abstract

Optical sensing has attracted more and more attention in recent years with the advance in planar waveguide fabrication processes. The photon, as a carrier of information in sensing areas, could have a better performance than electrons. We propose a novel end-to-end ring cavity to fabricate sensitive units of a strain sensor. We then propose a method of combining a flexible substrate with an end-to-end semiconductor nanowire ring cavity to fabricate novel strain sensors. We used a tuning resonant wavelength detected by a homebuilt excitation and detection system to measure applied strain. The resonant wavelength of the strain gauge was red-shift and linear tuned with increasing strain. The gauge factor was about 50, calculated through experiments and theory, and Q was 1938, with structural parameters L = 70 µm and d = 1 µm. The high sensitivity makes it possible to measure micro deformation more accurately. End-to-end coupling active nanowire waveguides eliminate the shortcomings of side by side coupling structures, which have the phasing shift with no minor optical density loss. This resonator in flexible substrates could be used not only as on-chip strain sensors for micro or nano deformation detecting but also as tunable light sources for photonic integrated circuits.

Highlights

Strain detection plays an important role in modern society, including for industrial fabrication, safety detection, scientific research, and human movement detection [1,2,3]
Micro/nano waveguides are a novel candidate for precious measurement due to the strong evanescent light field, which could interact with surrounding media [6]
The classic method of using photoluminescence of a semiconductor with a not wide bandgap was employed to absorb a photon, the excited carriers were relaxed through phonon emission, and the electron and hole recombined with the emission process into a photon

Summary

Introduction

Strain detection plays an important role in modern society, including for industrial fabrication, safety detection, scientific research, and human movement detection [1,2,3]. With a diameter of nano or micro structuration, reduce the dimensions of sensing structure and present higher sensitivity, lower power consumption, and a faster response [5]. Semiconductor one-dimensional structures such as nanowires have interesting and unique optical properties. They provide sub-wavelength optical phenomena, a large tolerance for mechanical deformation, and as well as the advantages of feasible composition methods, uniform strength, and a glaze surface. They have been researched and applied in electronics sensing and photonics [7].

Methods

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Discussion

Conclusion