Sill Optics will display its fully colour corrected F-theta scan lens for ultra-short pulse lasers. For lasers with pulses shorter than one picosecond, the laser creates a noticeable spectral bandwidth that will degrade the spot performance. For example, an 800fs Gaussian shaped pulse has a spectral width of about 2nm and a 250fs pulse has a width of almost 7nm. This will aberrate the spot in F-theta lenses which are designed to only focus one wavelength.
The two new scan lenses from Sill Optics use multiple glass types in their design enabling all the wavelengths in a pulse to be focussed at the work surface. The lenses have focal lengths of 100mm, are telecentric, have scan areas of 35 x 35mm and will accept a maximum 10mm 1/e2 input beam.