For many applications in laser material processing it is necessary to focus a Gaussian laser beam to the smallest possible spot size. In addition focused profiles often should be homogeneous. Therefore, TOPAG developed the so called FBSR beam shapers which create round Top Hat profiles with diffraction limited spot sizes. FBS stands for Focus-Beam-Shapers or Fundamental-Beam-mode-Shaping.
The FBSR beam shaper can be combined with any objective or F-Theta lens. FBSR can be included at nearly any position into the beam path (even in front of or within a beam expander/telescope). The diameter of Top Hat in the focal plane will be 1.5 times larger than the diffraction limited Gaussian focus and is approximately given by 2*λ*f/d or λ/NA with the numerical aperture (NA) of the focused beam. FBSR elements need to be matched to the laser wavelength (λ) and the (input) beam diameter (d).
|Efficiency||> 95% of input energy within Top Hat profile|
|Transmission||> 99%, incl. AR/AR coating|
|Material||UV Fused Silica|
|Dimensions||dia. 25.4mm/thickness 3mm|
|Damage threshold||4J/cm² @ 532nm and 10ns|
|Select beam diameter d (@1/e2)||1.0, 1.5 … 10.0mm|
|Tolerance for input beam diameter||< ±10%|
|Select wavelength/AR coating (standard)||1064/1030nm, 532/515nm, 355/343nm|
Other sizes and wavelengths on request.
Model No: FBSR - beam diameter - wavelength
- Input beam should be single mode Gaussian beam (TEM00) with M² < 1.4.
- Free/clear aperture should be min. 2.2times larger than beam diameter (@1/e²) along total beam path
Recommended equipment: x-y-positioner for alignment of the beam shaper in x- and y-direction. Topag offers two different adjustment mounts, HSF01 and HSF02 (+ assembling of beam shaper and mount).