Related Experiment Video
Updated: Jul 7, 2026

Terahertz Microfluidic Sensing Using a Parallel-plate Waveguide Sensor
Published on: August 30, 2012
Near-Infrared Refractometry of Liquids by Means of Waveguide ?erenkov Second-Harmonic Generation
Abstract:
A new, to our knowledge, method for measuring the refractive index of liquids in the near infrared by means of waveguide ?erenkov second-harmonic generation is presented. It makes use of a nonlinear planar waveguide whereby the liquid sample is put into place as the cover. By measurement of the output angle of the ?erenkov radiation mode (in the visible) the liquid sample refractive index (in the near infrared) is determined. Experiments were performed by means of a proton-exchanged LiNbO(3) waveguide as the sensor and a set of liquids with known refractive index. The values obtained are in good agreement with the expected ones, and the average accuracy is on the third decimal place.
Related Concept Videos
IR Spectrometers
Raman Spectroscopy Instrumentation: Overview
The monochromatic laser source, typically using visible or near-infrared radiation, generates a highly focused beam of light. This light interacts with the molecules of the sample, scattering some of the light. Liquid and gaseous samples are usually tested in ordinary glass capillaries, while solids can be analyzed as powders packed in capillaries or as potassium...
UV–Vis Spectrometers

