Possibilities of Multiphoton Microscopy in Semiconductor Nanomaterials Research

Multiphoton microscopy is the method using nonlinear optical effect which is two-photon absorption. It occurs when two identical photons are absorbed simultaneously. The photon energy should be around two times smaller than the photon energy for one-photon absorption. Thus, the excitation irradiation wavelength for multiphoton microscopy should be twice that for conventional confocal microscopy. Nowadays, multiphoton microscopy is widely used for biological research, but it is possible to apply this for non-biological materials studying, particularly, for solid-state materials and structures. Low-wavelength laser irradiation deep penetration, focusing and optical signal analysis possibility provides essential new challenges solving of hierarchical "smart" nanoparticles synthesis for target drug delivery, theranostics etc. In this paper we give an answer of some most popular questions about multiphoton microscopy. Nature and aspects of the multiphoton microscopy method were described. Advantages of this method in comparison with confocal microscopy method were shown. Multiphoton microscopy gives the best image contrast and the less photodamage and photobleaching of biological samples, and provides an opportunity of three-dimensional imaging of the biomaterials as well as the solid-state materials. Additionally, capabilities of this method for solid-state materials research were demonstrated by the porous silicon samples example. Also, multiphoton microscopy images of biological objects were shown.