Optical capillary-based interferometric sensor for detection of gas refractive index

Modal interferometric refractive index sensing in microstructured exposed core fibres

Optical fibre-based sensors measuring refractive index shift in bodily fluids and tissues are versatile and accurate probes of physiological processes. Here, we suggest a refractive index sensor based on a microstructured exposed-core fibre (ECF). By considering a high refractive index coating of the exposed core, our modelling demonstrates the splitting of the guided mode into a surface sensing mode and a mode that is isolated from the surface. With the isolated mode acting as a reference arm, this two-mode one-fibre solution provides for robust interferometric sensing with a sensitivity of u…

VIS和IR波长下折射率的干涉微尺度测量

Interferometric microscale measurement of refractive index at VIS and IR wavelengths

本文利用透反射光谱与SEM测量煅烧光刻胶SZ2080微盘的干涉条纹，在可见光与红外波段测得其折射率约为2.2，并讨论了微光学结构表征中的不确定性。

Using Cerenkov radiation for measuring the refractive index in thick samples by interferometric cathodoluminescence

Cathodoluminescence (CL) has evolved into a standard analytical technique in (scanning) transmission electron microscopy. CL utilizes light excited due to the interactions between the electron-beam and the sample. In the present study we focus on Cerenkov radiation. We make use of the fact that the electron transparent specimen acts as a Fabry-Pérot interferometer for coherently emitted radiation. From the wavelength dependent interference pattern of thickness dependent measurements we calculate the refractive index of the studied material. We describe the limits of this approach and compare i…

Automatic unit for measuring refractive index of air based on Ciddor equation and its verification using direct interferometric measurement method

In scanning probe microscopy laser interferometers are usually used for measuring the position of the probe tip with a metrological traceability. As the most of the AFM setups are designed to work under standard atmospheric conditions the changes of the refractive index of air have an influence to measured values of the length with 1.0e-4 relatively. In order to achieve better accuracies the refractive index of air has to be monitored continuously and its instantaneous value has to be used for compensating the lengths measured by all of the interferometric axes. In the presented work we develo…

白光光谱干涉法测量吸收介质中的折射率

Refractive index measurements in absorbing media with white light spectral interferometry

本文利用白光光谱干涉法测量吸收性液体在400-1000纳米范围的折射率，通过两步过程（不同厚度样品）克服吸收影响，实现全光谱折射率测量。

Linearized and Compensated Interferometric System for High-Velocity Traceable Length Calibration on a Metre Scale

We report on a traceable calibration system for a 3500mm-long console that carries a measurement system for inspecting the diameter of a circular reactor chassis. The system uses two single-pass laser interferometers with homodyne fringe detection for measurement in two degrees of freedom. The hybrid FPGA-microcontroller control module carries out the fringe detection together with the application-specific scale linearization approach and the compensation of environmental influences such as thermal elongation and the refractive index of air fluctuations. We demonstrated the system feasibility …