On the possible origin of bulk third harmonic generation in skin cells
Journal
Applied Physics Letters
Journal Volume
99
Journal Issue
11
Date Issued
2011
Author(s)
Abstract
We studied third harmonic generation (THG) of melanin solution with concentrations similar to melanocytes in human skin. In contrast to conventional observation of THG at interface, bulk THG was detected inside the solution due to the formation of melanin hydrocolloids. A linear relationship between melanin concentration and THG intensity was found, suggesting THG originated from high-order hyper-Rayleigh scattering. By fitting this linear relationship, third-order hyperpolarizability of melanin hydrocolloids was determined to be three orders larger than that of water. Our result will be useful for interpretation of THG signals in skin and other tissues containing colloidal particles.
SDGs
Type
journal article