Microscale diamond protection for a ZnO coated fiber optic sensor

Monika Kosowska,Daria Majchrowicz,Małgorzata Szczerska,Michał Rycewicz,Yafit Fleger,Mingzhou Chen,Mikhael Bechelany,Dror Fixler,Paulina Listewnik,Kishan Dholakia

doi:10.1038/s41598-020-76253-5

Abstract

Fiber optic sensors are widely used in environmental, biological and chemical sensing. Due to the demanding environmental conditions in which they can be used, there is a risk of damaging the sensor measurement head placed in the measuring field. Sensors using nanolayers deposited upon the fiber structure are particularly vulnerable to damage. A thin film placed on the surface of the fiber end-face can be prone to mechanical damage or deteriorate due to unwanted chemical reactions with the surrounding agent. In this paper, we investigated a sensor structure formed with a Zinc Oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) on the tip of a single-mode fiber. A nanocrystalline diamond sheet (NDS) attached over the ZnO is described. The diamond structure was synthesized in a Microwave Plasma Assisted Chemical Vapor Deposition System. The deposition processes of the nanomaterials, the procedure of attaching NDS to the fiber end-face covered with ZnO, and the results of optical measurements are presented.

Highlights

Fiber optic sensors are widely used in environmental, biological and chemical sensing
We investigate an undoped nanocrystalline diamond sheet attached to the Zinc Oxide (ZnO)-coated fiber-optic sensor head
This section contains the experimental measurements, which were performed to evaluate the influence of nanocrystalline diamond sheet attached over Atomic Layer Deposition (ALD) ZnO coating

Summary

Introduction

Fiber optic sensors are widely used in environmental, biological and chemical sensing. As new technologies become available, the structures of fiber-optic sensors are growing more elaborate, with integrated thin films, nanoparticles, microstructured fibers, which aim to offer increased sensing abilities One such group are thin film-based sensors that use nanolayers deposited on the fiber surface[10,11,12]. These are used to design and create structures that can be applied on the measuring heads of fiber-optic sensors, for example thin (tens of nanometers) dielectric layers made of materials characterized by high refractive index, e.g. ZnO (n = 2.1 at 500 nm)[13,14]. A set of such outstanding properties resulted in lots of applications of diamond in numerous fields of science, biomedicine and technology[18,19,20,21]

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