LF Series – Line Focus-Lenses
The LF series of lenses was first designed to enable production of square holes in cigarette filter tips.
The lenses produce a line focus by means of the introduction of a cylindrical lens element into what
is otherwise a ‘TF’ style 2 element assembly. (See Section 20.1). In one direction, the thickness of
the line, the performance is diffraction-limited; orthogonally, the length of the line is determined by
the cylindrical lens.
All models are based on use with a CO2 laser whose beam has a 2.0 milliradian far-field divergence.
Determination of the line size for other beam parameters requires calculation by ULO Optics. The
lenses are intended for use at 10.6μm wavelength.
Clear aperture : 25.4mm.
Lens material : Lasergrade ZnSe (3 elements).
Coatings: : All surfaces have low absorption anti-reflection coatings.
Sealing: : The lenses are assembled using indium wire for moderate gas
pressures up to 6 bar.
Cell material: : Aluminium HE30.
Finish: : Black anodised.
Cell size: : M11-type cell (See Fig 26.41)