Optical parametric oscillator (OPO) lasers have long been utilized in sophisticated test and measurement applications such as mass spectrometry, photoacoustic imaging, and spectroscopy. Now, these “tunable” pulsed lasers are being utilized to facilitate a range of tests at different wavelengths to qualify and quantify the performance of optical components such as fiber optic strands, filters, lenses, and coated mirrors.
Why are OPO lasers the way to go?
• The more precise the tests, the higher the quality of the product – a factor manufacturers can turn into a competitive advantage. Lasers, in general, have long been utilized in the testing and measurement of optical materials. By design, most optical components reflect, filter, or transmit specific wavelengths or ranges of wavelength. Therefore, it is critical to perform tests of component materials and coatings to ensure products perform as expected.
• There can be significant advantages to using pulse-based lasers. Although continuous wavelength lasers are an inexpensive solution for testing optical materials, they don’t provide a broad range of high-resolution wavelengths, and the peak power they can generate is limited. OPO lasers are more versatile, high-resolution options that can be “tuned” to specific wavelengths across a wide spectrum.
“Because there is such a range of tests, there is an advantage if the laser can be tuned to any required wavelength so manufacturers can ensure optical products perform as expected,” says Dr. Mark Little, Technical and Scientific Marketing Consultant for OPOTEK, LLC, manufacturer of tunable lasers for research and diagnostics.
• Better damage testing to determine the limits of the optical material. Certain wavelengths can trigger photochemical reactions in optical materials, changing their molecular structure or chemical composition and making them less effective. Some materials can absorb specific wavelengths of light, leading to localized heating and potential thermal damage. When the intensity of the light exceeds the damage threshold of the material it can lead to melting, evaporation, cracking, or other forms of physical damage.
• Superior detection of solarization. Some manufacturers may want to perform continuous testing to ascertain if an optical material may change over time. One concern is solarization, or “photobleaching,” which can occur due to prolonged exposure to UV or other forms of radiation. Solarization causes a gradual increase in the absorption of light, leading to a decrease in fiber performance – a concern with fiber optic materials.
• OPO lasers can deliver megawatts of energy, versus milliwatts for continuous wave lasers. To determine if optical components or materials will be damaged at peak power levels, pulse based OPO lasers deliver concentrated bursts of energy in short durations measured in nanoseconds.
Given the potential variety of tests at various wavelengths, optical component manufacturers should consider the merits of pulse based OPO lasers. The flexibility and resolution provided are ideal for determining the absorption, transmission, and reflection characteristics of materials and coatings, as well as damage testing. In doing so, manufacturers ensure optical products perform as expected and, over time, for the ultimate competitive edge.
For more information, call 760-929-0770 or visit www.opotek.com.