Opto Sigma

• Air-spaced design
• Standard focal lengths from 20 to 150mm
• High damage, narrowband, high performance Anti-Reflection coatings
• Barrel mounted for ease of use
• Optional protective windows available
• Matched focal lengths for YAG and HeNe wavelengths

These YAG lenses range in focal length from 20 to 150mm. They consist of either two or three air-spaced glass elements mounted in a metal cell. The lenses all have a 30mm clear aperture but they are recommended for use with beams not exceeding one inch in diameter. Two different designs are used - the 20, 30, 40, and 50mm focal length lenses have three elements, but the 60, 80, 100, and 150mm lenses use simpler two element designs. These lenses are Anti-Reflection coated with a high damage Narrowband Multilayer Anti-Reflection coating optimized to give less than 0.5% reflectance per surface at 1064nm.

These lenses are chromatically corrected so that a HeNe guide beam or a visible range video monitor beam will be in focus at the same position as the YAG beam.

Spot size or beam waist is inversely proportional to the numerical aperture at the effective beam diameter. The spot size given in the table is for a full aperture beam. Let us know your imaging requirements and we will be pleased to advise you on the appropriate lens for your application.

Since these lenses are often used with high power lasers we offer optional protective windows which can be attached to the focusing side of the lens. In the event of inadvertent back reflection of high energy beams into the lens it is likely that the window will absorb the incident energy and shatter preventing further damage to the lens itself. Protective windows are offered uncoated in packages of ten pieces. For optimum performance we advise that the protective windows be Anti-Reflection coated with our A46 V Coat at 1064nm.