Polymer Waveguide-Based Optical Sensors—Interest in Bio, Gas, Temperature, and Mechanical Sensing Applications

Abstract

In the realization of photonic integrated devices, materials such as polymers are crucial. Polymers have shown compatibility with several patterning techniques, are generally affordable, and may be functionalized to obtain desired optical, electrical, or mechanical characteristics. Polymer waveguides are a viable platform for optical connectivity since they are easily adaptable to on-chip and on-board integration and promise low propagation losses <1 dB/cm. Furthermore, polymer waveguides can be made to be extremely flexible, able to withstand bending, twisting, and even stretching. Optical sensing is an interesting field of research that is gaining popularity in polymer photonics. Due to its huge potential for use in several industries, polymer waveguide-based sensors have attracted a lot of attention. Due to their resilience to electromagnetic fields, optical sensors operate better in difficult situations, such as those found in electrical power generating and conversion facilities. In this review, the most widely used polymer materials are discussed for integrated photonics. Moreover, four significant sensing applications of polymer-waveguide based sensors which include biosensing, gas sensing, temperature sensing and mechanical sensing have been debated.

A Review of Photonic Sensors Based on Ring Resonator Structures: Three Widely Used Platforms and Implications of Sensing Applications

“…These WGs can be used for measuring changes in the RI of a surrounding medium. By detecting the shift in the guided light’s propagation characteristics, polymer WGs enable label-free sensing of analytes in liquids or gases [ 17 ]. This can be useful for applications such as chemical sensing, environmental monitoring, or detecting biomarkers in biological samples.…”

“…Some possible applications for polymer WG mechanical sensors include environmental monitoring, biomedical sensing, and structural health monitoring [ 108 , 109 ]. Polymer WG-based mechanical sensors come in a variety of designs, such as cantilever-based sensors, μ-RR sensors, and Mach–Zehnder interferometer (MZI) sensors [ 17 ]. A polymer multimode interference (MMI) coupler-based optomechanical pressure sensor with a high sensitivity of 8.2 ppm/Pa has been developed [ 98 ].…”

“…Many polymers have excellent transparency in the visible spectrum, allowing light to pass through with minimal absorption or scattering. This property is crucial for optical devices as it enables efficient transmission of light without significant loss [ 17 ]. Polymers can be engineered to have high flexibility, making them suitable for applications where bending or shaping is required.…”

Design and Realization of Polymeric Waveguide/Microring Structures for Telecommunication Domain

“…In order to couple light in and out of these resonant microstructures, an efficient way is to couple them with a standard waveguide. Integrated microring resonators and waveguides have been fabricated and tested on various materials, such as silicon, semiconductor, and polymer materials [ 10 , 11 ]. In particular, polymer materials have been proven to be a potential candidate to produce low-cost devices with a wide range of applications thanks to their advantages, such as availability, flexibility, and uncomplicated fabrication processes [ 9 , 12 ].…”

Chemresistive Detection of NO2 of ppb Level in Humid Air at 350 K Using Azo-Spaced Polycroconamide

“…Over the past few decades, extensive research has been conducted on NO 2 gas sensors. Various monitoring techniques have been developed, including electrochemical, optical, , surface acoustic wave, , calorimetric, microelectromechanical system, , and chemresistive , methods. While each sensing technology has its own advantages and disadvantages, cost and portability are two major factors to consider when using gas sensors in practical applications.…”