Birefringent tuners (Lyot filters) for wavelength tuning of lasers are made of crystal quartz or MgF₂ and their optical axis can be parallel to the surface plane or at customized angle. Standard thicknesses ranging from 0.5 mm to 10 mm and diameter of 25.4 mm (1 inch) are available from stock. Transmission ranges: 200 nm … 2700 nm for crystal quartz and 150 nm … 6000 nm made of MgF₂. ALPHALAS offers both uncoated and AR-coated birefringent tuners. These can be used at Brewster angle Lyot filter configuration (no Fresnel reflection losses), or in a customer-specific design.