SORL's COAR Series Laser Beam Expanders employ an Off-Axis, Afocal Dall-Kirkham design to provide accurate, unobstructed and achromatic expansion of any collimated input source. Similarly, they can be used in reverse to provide beam compression.
We offer model variations with expansion ratios from 2 to 100 power and output beam diameters to 250mm. To view Model specifications, click Catalog Beam Expander Models, or click Custom Beam Expander Worksheet for information on specifying a custom model.
Catalog Beam Expander Models
Custom Beam Expanders COAR Worksheet
Every COAR features an ultra-low thermal expansion ceramic primary mirror, and ceramic/metal secondary mirror. External focusing control of the secondary mirror and tilt adjust of the primary allow controlled focusing of either the input or output beams and fine tuning of the wavefront profile. The convex secondary eliminates internal focusing, a common concern in high power applications. All optical components are coated to provide 96% average system transmission.
Air Cooled, Variable Focus (VF)
Our standard, Air-Cooled, Variable Focus line provides a 1 lambda system wavefront (tested at lambda = .6328 microns), and is designed to provide diffraction limited performance at all wavelengths beyond 3 microns. Ceramic optics, with high efficiency optical coatings, are designed to withstand a maximum of 50 watts/CM2 CW Laser energy density at 10.6 microns.
High Quality, Air Cooled Models (HQ)
For applications involving visible and near infra-red lasers in which high wavefront integrity is desired, SORL offers a high quality version of each model in our standard line. Here the primary mirror is figured to a lambda/10 surface accuracy (lambda=.63281 microns), and interferometrically aligned to a high quality secondary mirror to provide a lambda/5 system wavefront. Focusing and tilt adjust control are provided. Complete interferometric data is supplied with each unit.
Water-Cooled, Variable Focus (WVF)
Thermal considerations and laser damage are critical in applications requiring energy densities greater than 50 watts/cm2 CW at 10.6 um. SORL's standard quality Water-Cooled Expanders meet this requirement by replacing the ceramic secondary mirror of our Air-Cooled line with a Water-Cooled OFHC copper mirror. High thermal conductivity of copper allows medium power CO2 lasers to be operated without concern, the energy dissipating through the housing. For applicationswith energy densities greater than 200 watts/cm2 CW or extended operating conditions, the water-cooling further extends the units application. These units provide a 1 lambda wavefront (lambda = .6328 um), and focus/tilt adjustments.
Water Cooled, High Quality (WHQ)
For high powered applications requiring high wavefront integrity, a high quality lambda/5 system wavefront (tested at .6328 um) is offered in our Water-Cooled models. Interferograms are supplied with every unit.
Variable Magnification (VMAG)
By introducing additional secondary mirrors with the appropriate focal length, magnification of a given unit may be adjusted within a small range of its designed ratio. For example, a COAR 10 X 10 may be modified in this fashion to provide 5 and 15 power expansion ratios as well. A decrease in system wavefront accuracy will be observed when employing this option, but it is often a desirable feature when "fine-tuning" energy density of your beam. SORL will be happy to discuss your application, and provide additional, pre-mounted secondary mirrors to meet your requirement.
For applications employing unfiltered beams, a limited line of spatially filtered Off-Axis Reflective Expanders are provided. A concave secondary is used to produce an internal focus, and a pinhole is placed at this point to improve uniformity of the output beam. Four models are offered. Ceramic optics, precision mounting and micrometer adjustments are provided for fine-tune focusing.
SORL will be happy to quote to your application requirements.