A compact readout platform for spectral-optical sensors

Abstract

Abstract. The continuous monitoring of industrial and environmental processes is becoming an increasingly important aspect with both economic and societal impact. So far, spectral-optical sensors with their outstanding properties in terms of sensitivity and reliability have not been considered as a potential solution because of the cost-intensive and bulky readout hardware. Here we present a card-size, inexpensive, and robust readout platform based on a wavelength-sensitive photodiode. In test and characterization experiments we achieved a wavelength shift resolution of better than 0.1 nm and a detection limit of 0.001 AU for ratiometric measurements. We furthermore discuss the capability and current limitations of our readout unit in context with interrogation experiments we performed with a photonic crystal-based fluid sensor. In sum we expect the presented readout platform to foster the exploitation of spectral-optical sensor technology for gas monitoring, chemical analytics, biosensing and many others fields.

Tungsten Oxide Photonic Crystals as Optical Transducer for Gas Sensing

“…However, in principle this signal is prone to be interfered by the intensity fluctuations of the incident light. As opposed to that, we have shown previously that even a simple setup utilizing two vertically stacked silicon photodiodes as detector allows one to determine the peak shift of a PhC film with high accuracy …”

“…However, in principle this signal is prone to As opposed to that, we have shown previously that even a simple setup utilizing two vertically stacked silicon photodiodes as detector allows one to determine the peak shift of a PhC film with high accuracy. 38 In addition, the observed response and regeneration times are shorter for the WO 3 PhC film compared to those of the nonordered WO 3 (Figure 11). This difference can be explained by the faster diffusion resulting from the more uniform wall thickness distribution and the lower content of thicker pore walls (i.e., higher surface to volume ratio) in the PhC sample (the wall stands for the materials between pores).…”

OS1.4 - A low-cost plasmonic sensing device for on-site detection of diclofenac molecules

“…To further minimize the optical unit and sensor size a compact and robust optical transmittance configuration was set up additionally, which relies on a novel photocurrent-based read-out approach [4]. Initial experiments with a focus on the applied surface functionalization to demonstrate the sensitivity of the holistic plasmonic sensor system for the detection of diclofenac molecules in the low µg/L range will be presented.…”

Determination of Specific Volume Fractions in Multicomponent Liquids Using Hydrogel-Functionalized Plasmonic Sensors

“…This enables very compact and simple, as well as low-cost sensor setups, which are suitable for onsite implementations. Moreover, it is possible to apply them in a compact readout platform using double photodiodes for very simple signal evaluation, further reducing the cost and complexity of the sensor setup [26], [27]. To selectively detect the concentration of a single substance using plasmonically active, refractive index-sensitive sensor systems, a chemical functionalization of the sensor surface is necessary.…”