Fabrication and measurement of optical waveguide sensor based on localized surface plasmon resonance

Assessment of the Influence of Protective Polymer Coating on Panda Fiber Performance Based on the Results of Multivariant Numerical Simulation

This article considers the deformation behavior of Panda optical fiber using different models of material behavior for the tasks of predicting residual stresses after drawing when cooling from 2000 °C to room temperature (23 °C) and indenting the fiber into an aluminum half-space at different parameters. These studies were conducted for single- and double-layer protective coatings (PCs), at different values of external load and thickness of single-layer PC. This paper determined the fields of residual stresses in the fiber formed during the drawing process. They are taken into account in modeling the fiber performance in the further process of this research. This article investigated two variants of PC behavior. The influence of behavior models and the number of covering layers on the deformation of the "fiber-half-space" system was analyzed. This paper establishes qualitative and quantitative regularities of the influence of the external load magnitude and relaxation properties of PCs on the deformation and optical characteristics of Panda optical fiber.

Dynamic correction of optical aberrations for height-independent selective laser induced etching processing strategies

Optical aberrations are a critical issue for tight focusing and high precision manufacturing with ultrashort pulsed laser radiation in transparent media. Controlling the wave front of ultrashort laser pulses enable the correction of low order phase front distortion and significantly enhances the simplification of laser-based manufacturing of 3D-parts in glass. The influence of system-inherent, dominating aberrations such as spherical and astigmatic aberrations affect the focal area, the beam caustic and therefore the focus intensity distribution. We correct these aberrations by means of a spatial light modulator (SLM) for various processing depths in glass thickness of up to 12 mm. This flexible aberration correction significantly simplifies the process control and scanning strategies for the selective laser induced etching process. The influence on the selectivity is investigated by comparing the three different focus conditions of the intrinsic microscope objective aberration corrected, the aberrated and the SLM aberration corrected beam profile. The previously necessary pulse energy adjustment for different z positions in the glass volume is compensated via SLM aberration correction in the end. Furthermore, the spatial extend of the modified and etched area is investigated. In consequence, a simplified scan strategy and depth-independent processing parameters can be achieved for the selective laser induced etching process.

Slab waveguide-based particle plasmon resonance optofluidic biosensor for rapid and label-free detection

We demonstrate a cost-effective, rapid, and sensitive slab waveguide-based particle plasmon resonance biosensor with enhanced optical near field through the localized surface plasmon resonance effect for practical clinical applications.

High-Aspect-Ratio SU-8-Based Optofluidic Device for Ammonia Detection in Cell Culture Media

Miniaturization of sensing technology has led to the development of multifunctional micro total analysis systems (μTAS) that benefit from microfluidic technology. Optical sensing is one of the most commonly used sensing approaches integrated into μTAS devices and features high sensitivity and low detection limits. Different materials have been used for the fabrication of μTAS devices, each having their advantages and disadvantages. Herein, a high-aspect-ratio optofluidic waveguide fabricated from SU-8 is presented for the first time. The suitable optical properties and chemical inertness of SU-8 provide a durable device made by a flexible and cost-efficient fabrication process. The optofluidic device was used for colorimetric ammonia (NH₃) sensing with a dynamic range of 3-70 μM, a detection limit of 2.5 μM, a response time of 8 min, and close to 10 times better analytical performance compared to using a standard microplate reader. The μTAS device was capable of monitoring NH₃ accumulating in the cell culture media of prostatic epithelial cell (BPH-1) culture.