| pubmed-article:21613673 | pubmed:abstractText | We report a theoretical study of second-harmonic generation (SHG) from the collagen fibrils which have a tilt angle ? between their axes with the plane of the polarization angle ? of the linearly polarized focused light. The effects of ? as well as ? on SHG emission have been investigated. Our results show that the total strength of SHG electrical field (E(2?)) and power (P(2?)) reach their maximal values as ? locates at a certain angle, here it is around 27° under all demonstrated ?. When ? < 27°, E(2?) and P(2?) gradually increase to their maximal value, while when ? > 27°, they quickly drops. Specially, E(2?) and P(2?) are almost undetectable when ? ? 45°. Also, ? influences the distribution pattern of E(2?), P(2?) and their parallel (E(2?,p), P(2?,p)) and perpendicular (E(2?,s), P(2?,s)) components, such as the number of emission lobes and shape. ? has unevenly impact on E(2?) and P(2?), the far deviation of ? from x axis induce much great decrease of E(2?) and P(2?). ? = 45° has special influence on the distribution pattern of E(2?,s), E(2?), P(2?,s) as well as P(2?) compared to those of ? = 0° and 90°. | lld:pubmed |
