Integrated optical sensors for the chemical domain

Abstract

During the last decade there has been a rapidly growing interest in integrated optical (IO) sensors, especially because many of them principally allow for sensitive, real-time, label-free on-site measurements of the concentration of (bio-) chemical species. This review aims at giving an overview of the most relevant developments in this area. After a general introduction into the field of IO sensors for the chemical domain, relevant aspects of integrated optics and chemical sensing are presented in short. A large variety of IO sensing platforms are introduced and discussed: interferometers, resonators, coupling-based devices such as grating couplers and surface plasmon resonance based sensors and finally a new class of sensors based on chemically induced field profile changes. Strong and weak points of principle and of configurations based on these principles are indicated and the main performance data of the IO sensing platforms, especially the obtained resolution, are indicated. Best resolutions of the chemically induced refractive indices on the order of magnitude 10−6–10−8 RIU can be obtained, corresponding to a resolution of 10−3–10−5 nm in the chemically induced growth of layer thickness of chemo-optical transducer materials. Depending on the analyte and the type of transduction layer chemical concentrations down to some ppb or some pg ml−1 can be determined. Several IO sensing systems are commercially available. Extension of individual sensors to sensor arrays is treated and finally an outlook for the future is given.

Sensitivity of Chirowaveguides to Circular Birefringence by First Order Perturbation Theory

“…The first term is generally maximized by using a combination of materials leading to high contrast in refractive index (∆n ∼ 0.3) and by working with thin guiding layers (thicknesses of a few hundreds of nm) [11]. The eccentricity, on the other hand, takes significant values in chirowaveguides with high rotary power, small index contrast and thick cores [4].…”

“…The idea is to combine the compactness and flexibility of evanescent planar wave sensors [11] with the unique ability of chirowaveguides to support the propagation of circularly polarized waves. Basic optical waveguide sensor devices are fabricated from a thin film of high refractive index, the core, coated on a substrate of lower index.…”

“…Various papers [11,13] have been published on how to accomplish this task for achiral waveguides. The goal of this work is to decide whether or not chirowaveguides may be used as circular birefringence sensors.…”

Spectropolarimetric analyses of optical single mode SU8 waveguide layers

“…Thanks to researches and the development of integrated optics devices for optical applications in the telecommunications, relatively cheap sources and detectors of optical radiation that can be used in the design of planar optical sensors [1,2]. These sensors are immune to electromagnetic interferences, including the danger of electric shock and electrically initiated explosion.…”

Modification of inkjet printer for polymer sensitive layer preparation on silicon-based gas sensors

“…1 Gas sensors based on microelectromechanical systems (MEMS) and silicon-based optical waveguide technologies have become a key focus in the study of gas sensors. 2,3 In the process of developing such sensors, polymer-sensitive layers in specific shapes need to be prepared in designated areas of silicon wafer. Furthermore, in order to detect different chemical compositions, a variety of sensitive materials should be deposited to constitute a sensor array.…”