Partial reflectors are used in laser cavities or outside the laser to split the beam. In the former case, the coatings will specified for normal incidence and for the latter, the coating is usually for use at 45 degrees angle of incidence. When used at non-normal incidence, the polarisation also needs to be considered, S , P or R (same as AV). The most common beam splitter coating is a 50% for splitting the beam into two equal power beams.
Dimensional tolerances for standard lenses, windows and mirrors are as follows:
Diameter: +0/-0.1 mm for most diameters, +0/-0.05 mm for 1.5″ lenses
Centre thickness: +/-0.1 mm
Edge thickness variation: most lenses within 0.03 mm and some within 0.05 mm
Focal length: +/-0.5%. Some long focal singlet scanning lenses can be 1 to 2% due to highly meniscus shape
Surface form: typically less than 1 visible fringe on a 38 mm diameter test area
Surface roughness: within 20 Å rms
Tighter tolerances are possible on custom optics. Sometimes they are interrelated if very tight, e.g. the achievable flatness on a window can depend on the thickness (rigidity).
ULO Optics is an ISO certified company and quality is at the heart of everything we do. With a host of industrial affiliations you can rely on ULO to deliver.
Beam Expanders for 1μm lasers
ULO Optics are excited to introduce our new range of beamexpanders. Designed for low power (500w) lasers such as Nd:YAG and Yb doped fibre lasers operating near the 1μm wavelength. The beamexpanders are of Galillean design and use Multi-spectral Zinc Sulphide for the optics which has an absorption at 1μm of 0.0005cm−1 (Similar to ZnSe at 10.6μm).
Diversification into 1 micron optics
ULO Collaborate on the LaserSnake2 project, developing laser cutting optics for safe, remote cutting in air and in water, focused on nuclear decommissioning.
ULO Optics develops CO2 Brewster plate beamcombiner
In our new beamcombiner – C-BC-2, pairs of enhanced Brewster Windows are used to attenuate a linearly polarised CO2 laser beam. The Brewster plate acts like a polarising beamsplitter. The difference in reflectance also allows two perpendicular polarised beams to be combined into a single beam.