Most of the commercially available dye lasers are either Fluorescein or Rhodamine laser dyes. Rhodamine dyes have efficient fluorescent characteristics, and can be detected using fluorometers.
Rhodamine 6G dye laser exhibits efficient laser action and lases at around 590 nm in the spectral region. It possesses excellent photostabilty, and hence it is widely used as a reference dye in order to evaluate the efficiencies of other dyes. The photostability of rhodamine 6G can be further improved by replacing its phenyl group with –CF3 group. Most of the rhodamine lasers exhibit efficient laser action in the 560 to 800 nm region.
Rhodamine 700, on the other hand, is another efficient laser dye that exhibits laser action between 700 and 800 nm in the spectral region. It has a 'double butterfly structure, which makes the amino groups more strong and planar.
||Flash lamp or other laser
||570 - 640 nm
Rhodamines are commonly used in photocoagulation therapy and ocular photodynamic owing to its large numbers of wavelengths of high output power.
Laser lithotripsy using rhodamine 6G dye laser is one of the safest and effective method that allows fragmentation of complex bile duct stones under radiological conditions.