Pyrromethenes belong to the family of highly efficient laser dyes that exhibits effective laser action and effective laser action owing to their weak triplet-triplet absorption and planar structure. The spectral region for emission and lasing properties of pyrromethanes is between 550 and 650 nm.
The pyrromethene dye lasers have efficient tunability and less maintenance than a conventional liquid dye laser. The laser is tunable in the green–yellow visible region of the spectrum. The photostability and thermo-mechanical stability of pyrromethene dye laser have enabled development of various solid matrices such as sol-gel, epoxies, glasses, xerogels and modified PMMA.
The key properties of pyrromethane dye laser include:
- High fluorescence quantum yield
- Large molar absorption co-efficiency
- Low rate constant of intersystem
- High lasing efficiency
- Good photostability.
Among the pyrromethene family of dye lasers, pyrromethene 567 (PM567) dye laser is of high importance has good absorption rate at the green region of wavelengths, and hence it is well-suited for efficient pumping with high-repetition rate pump lasers.
||Flash lamp or other laser
||550 - 650 nm
The unique operational flexibility of pyrromethene dye lasers has resulted in several applications in the field of science and technology. Their ability to provide tunable, narrow band-width radiation has enabled them to be used in high-resolution atomic and molecular spectroscopy.
Other applications of pyrromethene dye laser include the following:
- Isotope separation
- Cancer photodynamic therapy
Sources and Further Reading