Three-dimensional (3D) laser lithography, also referred to as two-photon polymerization, is an advanced method of generating intricate, three-dimensional microstructures with extremely fine resolution. Using high energy pulses on the femtosecond domain, IMRA’s femtosecond fiber lasers can exploit nonlinear interaction processes, such as two-photon polymerization, to lithographically generate complex structures with sub-microscale dimensions.
Through tight focusing, the intensity of a laser beam can be restricted to the laser spot which may be as small as a single wavelength (~1 µm). 3D laser lithography exploits the high selectivity of IMRA lasers to initiative localized two-photon polymerization in photosensitive materials, or photoresists. This specific light absorption initiates the bonding and hardening of illuminated regions. By scanning the focal spot, prescribed 3D structures can be printed with unprecedented resolution.