Effect of refractive index mismatch on forward-to-backward ratios in SHG imaging

authored by

Jarno N. Van Der Kolk, Stéphane Bancelin, Charalambos Kioulos, Antonino Calà Lesina, François Légaré, Lora Ramunno

Abstract

Nonlinear optical imaging in the epi-direction is used to image subresolution features. We find that a refractive index mismatch between the object to be imaged and the background medium can change the far-field intensity image. As an example, we study second harmonic generation (SHG) microscopy where the forward-to-backward (F/B) ratio is used to quantify subresolution features. We show both theoretically and experimentally that the inhomogeneous refractive index in collagen tendon tissue creates near-field effects, which can change the F/B ratio by ∼20%-25%, even though the effect is negligible for most of the individual fibrils in the tissue. This is caused by the sensitivity of the backward signal on phase matching conditions.

External Organisation(s)

University of Ottawa
INRS Universite d'avant-garde

Type

Article

Journal

Optics letters

Volume

43

Pages

5082-5085

No. of pages

4

ISSN

0146-9592

Publication date

15.10.2018

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Atomic and Molecular Physics, and Optics

Electronic version(s)

https://doi.org/10.1364/ol.43.005082 (Access: Closed)