Laser Damage Testing
A potentially invaluable resource to your operation
Optics damage is a major cause of laser failure. Knowing that your laser optics can withstand expected fluence levels is a key to long-term system reliability. Quantel USA pioneered laser damage testing of optical components and remains the premier test site facility in the nation. Damage threshold, durability certification, optical density and other exposure test services are available at key laser wavelengths (266 nm, 355 nm, 488 nm, 514 nm, 532 nm, 694 nm, 755 nm, 1064 nm, 1.54 µm, 10.6 µm, 1.57 µm, 2.09 µm, 2.94 µm).
“Damage” is usually defined as any permanent laser-induced change which is observable at high magnification with a differential interference contrast of dark field microscope. It may be defined differently if the application requires. “Threshold” is defined to be the lowest fluency sufficient to induce damage at any test site. To determine the damage threshold, a number of sample sites are irradiated at different fluences.
Quantel USA offers the damage frequency method of testing as well as the least fluence failure method.
This test is used to verify optic durability to a drawing or other procurement specification. Several test sites (usually chosen on a uniform grid and sampling a representative surface area) are exposed to laser radiation at one specified combination of fluence, repetition rate, pulse duration, spot size and minimum number of pulses per site. The sample is observed as before with the on-line 20x microscope and damage at any site constitutes “failure” in this test. This test is usually done on optics intended for use in laser hardware and seldom on witness samples.
Transmission vs. Fluence
Some optics, such as optical power limiters, have a nonlinear transmission response with exposed fluence level. This test generates the plot describing this optic characteristic. Such specialized exposure tests are performed to customer requirements. Test procedures are on a case-by-case basis.
This test measures the ratio of incident to transmitted fluence (or irradiance) under customer specified exposure conditions. BSLT has facilities to perform such testing under realistic temperature and humidity conditions as well.
As an example, the lifetime test is an extended version of the certification test when durability must be demonstrated over a prolonged operating period. The sample is exposed for the specified length of time or number of pulses. Photomicrographs of the test site before and after exposure are compared to identify and characterize changes. Other examples of specialty testing include simultaneous exposure at two wavelengths, long pulse Nd:YAG and glass bulk darkening threshold.
For more information on our testing options or to obtain a price quotation,
download our Damage Test Descriptions
or contact us:
Phone: (+1) 406 586 0131
Fax: (+ 1) 406 586 2924
Our damage testing staff will be happy to assist you.