This was in the latest SPIE news letter.
Tunable blue-output laser diode sources offer new performance-cost opportunities for spectroscopy applications. Previously, researchers wanting to perform experiments in atomic physics and chemistry have had limited options in achieving a tunable CW blue-light source. Usually, they resort to one of three possibilities--a frequency-doubled dye laser, a Ti:sapphire laser, or, more recently, frequency-doubled semiconductor lasers.
Frequency-doubled dye and Ti:sapphire systems are bulky and require an expensive high-power pump-laser source. Besides cost and size, these systems have additional problems with output power levels and stability. They require nonlinear crystals for frequency doubling, which are inefficient unless an intracavity approach is used--but this often leads to complicated solutions suitable only for highly trained people. While they can generate several hundred milliwatts of tunable blue laser light, these systems typically cost more than $100,000.
As an alternative approach for limited power requirements, TuiOptics already offers much smaller CW frequency-doubling systems based on near-infrared laser diode sources with selected nonlinear crystals for frequency conversion of the output to the green and blue. A tunable output of 15 mW at 490 nm or 5 mW at 430 nm, for example, can be achieved with these systems. The new blue-violet ECLD systems will, however, be priced about 75% less than these frequency-doubled laser diode systems.
In addition to the price advantage, the new blue-violet ECLD platforms offer the best amplitude stability of any laser source at this wavelength, including fixed-frequency gas lasers. The near-term prospect of higher output power and wider wavelength coverage also makes for a bright future for the ECLD platform. With the availability of the first violet-blue laser diodes, many exciting new products are just around the corner. First to market, however, will be more affordable, higher-performance spectroscopic systems.
Colin - Thu, Jun 07, 01 12:20:46 AM
This might help.
external cavity semiconductor laser (ECLD) 64.170.192.178