Photoluminescence is a form of luminescence - an emission of light from a material caused by the absorption of energy - whereby light energy is absorbed, causing the material to emit at a different wavelength.
Lasers for Fluorescence and Photoluminescence
Photoluminescence is a general term covering the two light emitting mechanisms of fluorescence and phosphorescence. In the most rigorous sense, fluorescence is the emission of light from an electron excited into one of its singlet states within the material - commonly a very fast emission following excitation - whereas phosphorescence is the emission of light from the triplet state - causing a slower and more delayed emission of light.
These terms are often not used in this specific way and generally fluorescence can be thought of as a fast process of light emission following excitation, often on the nanosecond scale or below, in comparison to the slower phosphorescence, often considered on the microsecond scale or above.
While much photoluminescence is possible with broadband sources, high spectral and spatial precision is required for a wide number of applications, such as confocal microscopy, crystalline defect inspection or dynamic mixtures of fluorochromes and fluorophores.
Many applications make use of fluorescence in conjunction with other measurements, such as Raman, where the ability to use the same excitation source for both techniques’ eases integration and analysis of data. A typical example would be solar cell manufacturing and research, where highly structured surfaces are analysed using both techniques – fluorescence to examine inherent properties such as carrier lifetime or efficiency, and Raman Microscopy to determine feature homogeneity, for instance.
UniKLasers design and manufacture single frequency continuous wave laser sources with unrivalled wavelength stability and narrow linewidths - designed for integration over a range of wavelengths within a small footprint. We currently offer single frequency lasers in the red and green areas of the visible spectrum with our Solo 640 Series and Duetto 532 Series respectively, along with our infrared Solo 1064 Series and ultraviolet Duetto 349 Series.