Luminescence is the decay from the excited state to the ground state

Luminescence is the emission of a photon with the decay of an electron from an excited state to the ground state.  Different decay paths describe different types of luminescence.  For example, fluorescence occurs with the decay from the singlet S1 to the S0 ground state directly and is generally on the nanosecond time scale.  Phosphorescence occurs when the decay is from a triplet state to the S0 ground state and generally takes much longer. 

The excitation to the excited state occurs by absorption of energy.  The most common energy source is a light source.  However, chemical reactions (chemiluminescence), electricity (electroluminescence) and more can all act as means to achieve the excited energy state.

Luminescence spectrometers are designed to collect and measure the emitted photons.  The microspectrometer can be configured as a luminescence spectrometer which is combined with a microscope.  They are designed to measure  luminescent spectra of microscopic samples or microscopic areas of larger objects.  There are two basic types: the fully integrated microspectrophotometer that has been built and optimized for luminescent microspectroscopy and the spectrophotometer unit designed to attach to an open photoport of an optical microscope.   The beauty of microspectrometers is that they can also be configured to measure the transmission and reflectance spectra of microscopic sample areas in addition to luminescence.  And with special software, they are capable of colorimetry as well.

A CRAIC Technologies™ microspectrometer is a purpose-built system that allows you to analyze UV-visible-NIR range luminescent emissions non-destructively and with no sample contact.  Capable of analyzing even sub-micron areas, they are also capable of high resolution digital imaging.  Designed for ease-of-use, they are durable instruments designed for microscale spectroscopy.

To learn more about microspectroscopy and microspectrometers, select one of the following links: 

What is a Microspectrometer?

Microspectrometer Design

Uses of Microspectrometers

20/30 PV™ Microspectrophotometers