What are Photoluminescence Lasers?
Photoluminescence lasers are typically laser diodes or DPSS lasers, emitting short wavelengths in the UV or Blue spectral regions, utilized for measuring a semiconductor’s bandgap, for example.
So, what is Photoluminescence?
Photoluminescence (also photoluminescence spectroscopy or fluorescence spectroscopy in chemistry) is a generalized term for exciting light emission from a material utilizing a short-wavelength light source as the excitation source. While this term applies to many different optical applications, the more common usage is for measuring a semiconductor’s bandgap. This process, commonly used in testing laser diodes and light-emitting diodes (LEDs), utilizes short-wavelength (typically blue or ultraviolet) photoluminescence lasers to excite the electrons from the valence band to the conduction band. Then when they relax back down the valence band, they emit light whose energy is equal to that of the band gap. By measuring this emission, LEDs and laser diodes can then be sorted and binned according to their emission properties. On this page, you will find a list of all of the photoluminescence lasers we offer, including UV and visible diode and DPSS lasers.
The classification of different photoluminescence processes is determined by various parameters like the photon’s excitation energy with respect to emission. When photons with a specific wavelength are absorbed, causing the rapid re-emission of identical photons, we call this process resonant excitation or resonance fluorescence.
For gases or solutions, this process does involve electrons. However, there are no significant internal energy transitions between absorption and emission involving molecular features of the chemical substance.
Secondary emission can be more complicated for electronic band structures in crystalline inorganic semiconductors because events may contain both coherent and incoherent contributions. Coherent contributions include resonant Rayleigh scattering, where a fixed phase relationship with the driving light field is maintained (i.e., energetically elastic processes where no losses are involved). In contrast, incoherent contributions involve inelastic modes where some energy channels into an auxiliary loss mode.