A broad category of nonlinear 3D fabrication
Multiphoton lithography uses an intense, localized optical field to drive a material response whose probability rises nonlinearly with light intensity.
The phrase is useful because it describes a family rather than insisting that every exposure follows one identical microscopic route. The material response may be polymerization, crosslinking, bond cleavage, photoacid generation, or another persistent modification. The common idea is that nonlinear excitation confines useful processing around the illuminated region.
Two-photon lithography is a subset, not a competing name
Two-photon lithography specifies a two-photon excitation picture. Multiphoton lithography leaves the excitation order broader. Direct laser writing specifies the spatial writing method and can also include linear absorption or non-polymer material modification.
Nonlinearity changes the exposed volume
For an idealized n-photon process, the excitation source scales approximately with the local intensity raised to the power n. Regions below the peak shrink disproportionately as the order increases. A subsequent material threshold can confine the persistent modification further still.
s ∝ Is ∝ I²s ∝ IⁿThis compact scaling is an intuition, not a complete material model. Saturation, depletion, sequential states, diffusion, inhibition, and thermal effects can all change the observed response.
The fabrication chain remains recognizably similar
Most scanning implementations still require a digital geometry, a trajectory, a focused ultrafast field, a photosensitive material, and a post-exposure step. Parallel or projection strategies can modify how exposure is delivered, but they do not remove the need to connect optical excitation to a persistent material change.
MPL, MPP and MP3DL foreground different parts of the same family
Broad patterning term.
Specifies polymer-forming chemistry.
Explicitly identifies true three-dimensional fabrication.
Broad application language across materials.
This lab currently models the two-photon branch
The interactive laboratory uses a two-photon source proportional to squared local intensity. It does not expose an adjustable photon order or claim to represent every multiphoton mechanism. The wider vocabulary belongs in the field guide; the narrower mechanism belongs in the model contract.
See where this model sits →Sources for the broader field
- 01Multiphoton 3D lithographySkliutas et al. · Nature Reviews Methods Primers · 2025↗
- 02Multiphoton fabricationLaFratta et al. · Angewandte Chemie International Edition · 2007↗
- 03Three-dimensional microfabrication with two-photon-absorbed photopolymerizationMaruo, Nakamura & Kawata · Optics Letters · 1997↗