Telecentric F-Theta Scan Lenses

In a standard F-theta lens, the incident beam will be normal to the surface only along the axis of the lens. When the laser beam is off axis, the beam strikes the surface at an angle so the spot will be elongated and if drilling or cutting, the wall angle will not be perpendicular to the top surface.

A telecentric F-theta lens is designed so the beam is normal to the surface anywhere in the scan field resulting in a round hole which is perpendicular in a drilling application or a wall which is perpendicular in a cutting application. Since the input beam is normal to the surface, the output lens diameter must be at least as large as the scan field.

The aperture stop distance is the suggested location where the scan mirrors should be placed symmetrically around the len in order to obtain optimal performance. In a one mirror system, this value is the position of the scan mirror. The calculation of the scan length and scan areas of our f-theta lenses are based on the geometrical design of typical scan systems with a certain mirror spacing. The values given assume a vignetting of less than 1%. If used with non-typical scan systems or with scan systems which have been designed for larger or smaller laser beams, different scan lengths and scan areas will result.

Lens Specifications

Scan Specifications

Newport Resource e-Catalogs *

• Newport Resource e-Catalog, page 816 (English)
• Newport Resource e-Catalog, page 816 (French)
• Newport Resource e-Catalog, page 816 (German)