Thin Lens and Thermal Lens

Thin lenses are model lenses that focus or defocus the beam, but have zero thickness. In most cases practical, physical lenses can be modelled as thin lenses with a good results. The apparent thickness of thin lens icons drawn on the Canvas is for display only.

Within a refractive element, only thermal lenses can be inserted. The thermal lens is centred within the element.

To insert a lens or thermal lens, select menu Edit | Insert | Insert Lens or click the Insert Lens button on the toolbar.

Focal Length (mm)

Specifies the focal length of the lens, in units of mm (10^-3 m). If the focal length is 0, the laser mode passes through the lens unaffected. A positive focal length focuses the beam, negative causes the beam to diverge.

If the Astigmatic option is checked, then separate values can be entered for the lens optic’s focal length in the sagittal and tangential planes.

Astigmatic

Checking the Astigmatic box allows separate sagittal and tangential values to be entered for the Lens or Thermal Lens optic’s Focal Length property.