Performance of a compact, hybrid optical evanescent-wave sensor for chemical and biological applications

Abstract

We describe a hybrid evanescent-wave sensor component that we fabricated by using an integrated optical interferometer with a specially adapted photodetector array. The design of the interferometer is based on the use of tapered waveguides to obtain two intersecting collimated beams. Phase shifts can be measured with an angular precision of better than 10(-3) rad, which corresponds to a superstrate index change inferior of 10(-6) with our structure. The interest in the device as a chemical sensor is experimentally demonstrated. The same optical component could be used in a variety of other sensor applications, e.g., biological and immunological sensors.

Chemical Gas Sensor Application of Open-Pore Mesoporous Thin Films Based on Integrated Optical Polarimetric Interferometry

“…The use of bulk light beams to directly interact with the porous sensing layers makes these existing sensors excluded from the family of integrated optical chemical sensors. Chemical sensors based on integrated optical technology are of considerable current interest, which generally employ an evanescent wave as probe to interact with the sensing layer, thereby sometimes called evanescent-wave sensors . In general, evanescent-wave sensors are very sensitive because they allow for extending the path of interaction between the evanescent wave and the sensing layer up to several centimeters long.…”

“…In general, evanescent-wave sensors are very sensitive because they allow for extending the path of interaction between the evanescent wave and the sensing layer up to several centimeters long. Conventional evanescent-wave sensors with dense and low-refractive-index thin films as the chemical-sensing layers are limited to surface detection. , In contrast, mesoporous thin films serving as the chemical-sensing layers enable the evanescent-wave sensors to detect molecular interaction occurring at both the outer and inner surfaces of the film. It is thereby anticipated that mesoporous thin-film-based evanescent-wave sensors are much more sensitive than conventional counterparts.…”

Spectroelectrochemical Sensing Based on Multimode Selectivity Simultaneously Achievable in a Single Device. 9. Incorporation of Planar Waveguide Technology

“…The potential advantages of waveguides − over MIR devices are several: (1) increased sensitivity and better detection limits due to higher density of reflections; (2) greater versatility in choice of optical designs, including more sophisticated configurations, such as Mach Zehnder interferometers; and (3) the ability to micromachine sensors in complex platforms. The uses of waveguides for chemical sensing have been amply reported in the literature. , Previously reported types of planar waveguide chemical sensors include channel − and slab (or planar) − designs and Mach Zehnder interferometers. − …”

Glass integrated optics: state of the art and position toward other technologies

“…Since the early beginning of glass integrated optics, a huge amount of studies have been carried out by several laboratories amoung the world. This work has led to the demonstration of several devices such as AWG 3 , wavelength multiplexers 4,5 , chemical and biological sensors 6,7 , optical amplifiers 8 and lasers 9 . Glass integrated optic presents a broad application range varying from astronomy and fluidic to telecommunications, which make this technology among the most popular.…”