Photoinitiators used in two-photon polymerization.
| PIs | Design strategies | Core structures | λ max (nm) | σ 2PA (GM) | Ref. |
|---|---|---|---|---|---|
| Water-insoluble TPIs | Symmetric charge transfer | Bis(styryl) benzene | 810 | 3670 | 59 |
| Bis(styryl) benzene | 775 | 1250 | 60 | ||
| Anthracene | 750 | 466 | 61 | ||
| Water-soluble TPIs | Supramolecular self-assembly | Anthraquinone, cyclodextrins | 780 | 200 | 50 |
| Anthraquinone, PF127 | 780 | 200 | 63 | ||
| BMVPC-CB7 | 567 | 2999 | 64 | ||
| Water-soluble dyes | Xanthene | Rose bengal-based | 800 | 10 | 67 and 68 |
| Eosin Y | 800 | 10 | |||
| Erythrosin | 800 | 10 | |||
| Benzylidene cyclanone | T1 | 820 | 567 | 71 | |
| T2 | 808 | ||||
| T3 | 231 |