These fiber collimators are a specially modified version of the series 60FC fiber collimators. They additionally have a radially arranged bore hole for flushing purposes.
The possibility of flushing these fiber collimators makes them suitable for UV applications. (Reference: Marciniak et al., arXiv:1704.05879)
Optics for the UV
Unlike the standard series 60FC fiber collimators this series is offered with fused silica lenses which are suitable for wavelengths starting from 250 nm. Since these are plano convex lenses, they are diffraction-limited for fibers with an NAe2 < 0.04 only. All lenses are AR-coated.
Adjustment of focus
Such as with the standard series 60FC fiber collimators, the distance between fiber end-face and collimating optics is adjusted by means of an eccentric key. The lens does not rotate when adjusting the focus. The final focus setting is locked by means of two radially arranged clamping screws.
Optimum lens performance
The angled polish of connectors of type APC is considered by a pre-angled mechanical coupling axis that compensates the beam deflection and you can use the lens centrically. This minimizes aberrations simply resulting from a non-ideal beam path through the lens.
The fiber collimator can be equipped with FC PC or FC APC receptacles. the fiber receptacle has an additional grub screw to increase pointing stability.
The fiber collimators are available in nickel silver.
There are special adapter rings with outer diameter Ø 25 mm e.g. for use with standard kinematic mirror mount or with system mount Ø 19.5 mm with a bore hole matching the bore hole of the fiber collimator. A thread allows for connecting a flush nozzle.