Femtosecond Direct Laserwriting / 3D Laserlithography

High energy radiation from a regenerative amplifier is focused into a transparent medium, e.g. fused silica. Multiphoton absorption in the focal region creates an high refractive localized index change, that can be used to fabricate different optical systems, such as photonic crystals, diffractive optical elements, waveguides, powersplitters, couplers, reflection gratings, etc.

 

Die physikalischen Effekte in optischen Materialien bei Beleuchtung mit Femtosekundenpulsen sind unterschiedlich. Es sind jedoch grundsätzlich drei Regime zu unterscheiden:

 

• High energy (> 1 muJ): Ablation, melting and microvoids (microchannels, surface structures)
• Medium energy (100 nJ - 1 muJ): Refractiv index changes in avalanche ionisation in glass (does, waveguides)
• Low energy (< 100 nJ): Two-photon polymerisation in photopolymers (photonic crystals, metamaterials)

 

Photonic crystal (lhs); diffraction grating (rhs).

waveguidearray (lhs); Bragg-grating in a waveguide (rhs).

micromixer in PMMA (lhs);

coupler in fused silica.

powersplitter in fused silica.

diffraction grating on a laser mirrorl (lhs); reflection  in SMF28 core (rhs).

Contact: Wolfgang Horn