Making a layer can be a problem if 100 nm resolution is required. Two-photon photopolymerization (2PP) makes sub-100 μm size parts having sub-100 nm resolution for medical, optical, and acoustical applications. With the help of a micro-mold created by 2PP, a complex structure of 2 μm resolution can be made by infiltration. L-beam consisted of femtosecond pulse is required to excite photopolymer and solidify it. In order to excite, two photons within an interval of 10−15 s are required. One photon excites the molecule to an intermediate virtual state, while another photon excites it from the intermediate state to the final state. If another photon is not available before the molecule loses its intermediate state and comes back to the ground state, the molecule will not be able to reach a higher excited state.