Aspheres

The term asphere means "non-spherical". It is used for all rotationally symmetrical and non-rotationally symmetrical optics. Possibilities for specifying aspherical surfaces are described in DIN ISO 10110-12.

Using ultra precision CNC machinery, LAYERTEC manages to process surfaces zonally so that the tool works on one point at a time. The possible surface forms and tolerances are only limited by the precision of the machine and the measurement equipment.

Fig.1:

a)Aspheric Surface

b)Off-Axis parabolic mirror

LAYERTEC offers a variety of aspherical optics within the specification limits listed in the table below:

Table 1:*valid for measurements with optical profilometer taking into account spatial structures in the 0.65 – 5 µm range.

Parameter	Dimension	Tolerances
Total Diameter	25 – 560 mm	< 0.1 mm
Inspection Range	< 550 mm
Total Thickness	< 100 mm	< 0.1 mm
Sagittal height	< 50 mm
Centering Error		< 50 µm
Tilting Error		< 30"
Surface form tolerance (PV)		< λ/4 (< λ/10 on request)
Roughness*		< 4 Å (< 2 Å on request)