This interference pattern consists of a periodic series of fringes representing intensity minima and maxima.
With multi wave interference (by inserting a diffuser into the optical path) aperiodic patterns with defined spatial frequency spectrum can be originated.
The spatial coherence guarantees a uniform wavefront prior to beam splitting.
Coherent light must be split into two or more beams prior to being recombined in order to achieve interference.
Typical methods for beam splitting are Lloyd´s mirrors, prisms and diffraction gratings.
The momentum of an atom is even larger than for electrons or photons, allowing even smaller wavelengths, per the de Broglie relation.
The benefit of using interference lithography is the quick generation of dense features over a wide area without loss of focus.
Seamless diffraction gratings on areas of more than one square meter have been originated by interference lithography.
[3] Hence, it is commonly used for the origination of master structures for subsequent micro or nano replication processes[4] (e.g. nanoimprint lithography) or for testing photoresist processes for lithography techniques based on new wavelengths (e.g., EUV or 193 nm immersion).
In addition, interfering laser beams of high-power pulsed lasers provides the opportunity of applying a direct treatment of the material's surface (including metals, ceramics and polymers) based on photothermal and/or photochemical mechanisms.
Due to the above-mentioned characteristics, this method has been called in this case "Direct Laser Interference Patterning" (DLIP).
[5][6][7] Using DLIP, the substrates can be structured directly in one-step obtaining a periodic array on large areas in a few seconds.
Such patterned surfaces can be used for different applications including tribology (wear and friction reduction), photovoltaics (increased photocurrent),[8] or biotechnology.