Related Experiment Video
Updated: Jun 12, 2026

Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing
Published on: March 22, 2019
Upconversion use for viewing and recording infrared images
Abstract:
The upconversion of 1.54-microm radiation to shorter wavelengths has been studied in CaF(2) crystals doped with Er(3+) ions. Experimental measurements of the intensity dependence and temporal behavior of the upconverted radiation give results in good qualitative agreement with a simple model of a cooperative luminescence process. Measurements with a silicon diode matrix array (DMA) of the spatial distribution of the luminescence from screens of CaF(2) doped with Er(3+), which were irradiated with an Er laser, showed that the resolution is not limited by the cooperative luminescent process but is determined by the granularity and/or thickness of the screens. Good results on 1.54-microm beam profiles were obtained with a computer-based image recording system incorporating the screen-DMA combination. A linear dependence on intensity without saturation of the DMA was achieved by interposing neutral density filters between the screen and the DMA.
Related Concept Videos
Infrared (IR) Spectroscopy: Overview
Different compounds display unique properties due to their...
IR Spectrometers
IR Spectrum
Transmittance is defined as the ratio of the radiant power passing through a sample to that from the radiation's source. Multiplying the transmittance by 100 gives the percent transmittance (%T), which varies between 100% (no absorption) and 0% (complete...
IR Frequency Region: X–H Stretching
Phase Contrast and Differential Interference Contrast Microscopy
In-phase-contrast microscopes, interference between light directly passing through a cell and light refracted by cellular components is used to create high-contrast, high-resolution images without staining. It is the oldest and simplest type of microscope that creates an image by altering the wavelengths of light rays passing through the specimen. Altered wavelength paths are created using an annular stop in the condenser. The annular stop produces a hollow cone of...
Attenuated Total Reflectance (ATR) Infrared Spectroscopy: Overview
The ATR process begins by directing a beam...

