Glossary of Spectroscopy Terms - StellarNet, Inc.

What is the Spectrometer’s Baseline Offset?

Nov 10, 2017 | Detectors, Electronics, Glossary of Spectroscopy Terms

The baseline offset is the number of counts generated by the detector when there is no light. Several sources of noise are always present, so it is impossible to have no counts. The main components of baseline offset are electronic offset, dark current, and readout...

Spectral Properties of Er3+/Tm3+ Co-Doped ZBLAN Glasses and Fibers

Oct 3, 2017 | Application, Optical Metrology, Optics, Physics

X Liao, X Jiang, Q Yang, L Wang, D Chen – Materials, 2017 Abstract A series of Er3+/Tm3+ co-doped fluoride (ZBLAN) glasses and fibers was prepared and their fluorescence spectra was measured under excitation at 793 nm and 980 nm. Correlation between the...

Micro-sized tunable liquid crystal optical filters

Oct 3, 2017 | Application, Optical Metrology, Optics, Physics

C Stoltzfus, R Barbour, D Atherton, Z Barber – arXiv preprint arXiv:1705.00983, 2017 Abstract Liquid Crystal Arrayed Microcavities (LCAM) is a new technology for ultra-narrow optical filtering (FWHM ~ 0.1 nm) that uses pico-liter volume Fabry-Perot type optical...

What is a Reference Spectrum?

May 25, 2017 | Glossary of Spectroscopy Terms, Software

This is a term used in the SpectraWiz software. For absorbance and transmittance, it is the initial intensity of the reference light and is used to calculate the two quantities. It is up to the user to determine the appropriate reference to use. Check out the General...

What is a Fiber Optic Cable’s Bend Radius?

May 25, 2017 | Glossary of Spectroscopy Terms, Sampling

Fibers can be damaged if they are bent too far. The bend radius is the the radius of the smallest circle a fiber can be bent into before it sustains damage. A smaller number means that a fiber can bend more sharply. The bend radius is proportional to fiber diameter,...

What is a Numerical Aperture?

May 25, 2017 | Glossary of Spectroscopy Terms, Properties of Light

Numerical aperture is a measure of how many angles of acceptance an optic can accept. It is described by the following equation: where NA is the numerical aperture, n is the refractive index, and is the cone angle. Assuming the optic is in air (n=1), the numerical...