We present a mobile laser lithography station for 3D structuring by microscopic two-photon
polymerization. For structuring the Coherent Vitara UBB titanium:sapphire femtosecond
laser is used, which has a power output of 500mW and generates pulses with a central
wavelength of 810nm. The laser pulses have a tunable bandwidth from 50nm to 250nm.
The pulses are temporally compressed using chirped mirrors to a minimum duration of
less than 15fs at the sample. The laser power reaching the sample can be motionless
controlled by a combination of a liquid crystal retarder and a polarizer within milliseconds.
The sample is placed onto a microscope stage which has a movement range of 300μm in
the X, Y and Z direction with an accuracy of 2nm. Sample imaging is possible with
a microscope camera simultaneous to the structuring. The pulses are focused by a 40X
microscope objective (1.3NA) onto the sample. To operate the lithography station,
we developed a LabVIEW-based software which controls sample position, laser power
and objective height and as well as the microscope camera. Furthermore, CAD data can
be read and converted into sample position data. By combining all these components,
a fully automatic structuring of a sample with sub-micrometer precision is possible.
