Combined SHG/THG Imaging

Szu Yu Chen, Chi Kuang Sun

Research output: Chapter in Book/Report/Conference proceedingChapterpeer-review


Currently, two-photon uorescence (2PF) microscopy is the most common technique used in combination with second harmonic generation (SHG) microscopy. Making use of the various endogenous uorophores found in bio-tissues, 2PF microscopy can provide more cellular, morphological, and molecular information regarding these tissues in addition to the SHG-revealed information; moreover, it can also help localize the SHG signals and identify the contrast sources of these signals. However, since 2PF microscopy is a uorescence-based technique, issues of photodamage and photobleaching due to multiphoton absorption are always of concern in the imaging process. To avoid such uorescence-induced concerns, third harmonic generation (THG) microscopy, a third-order nonlinear optical microscopy, could be used instead of 2PF microscopy. THG microscopy is well known to have interface sensitivity and can be used as a general-purpose type of microscopy to provide structural information of the tissues. Based on the characteristics of virtual-level transition and energy conservation, which are the same as in SHG microscopy, with a combination of SHG with THG, the problems of uorescence-induced photodamage and photobleaching could be avoided so as to reduce the invasiveness. Meanwhile, owing to its higher-order nonlinearity, a higher spatial resolution can be achieved with THG microscopy. In this chapter, combined SHG/THG microscopy will be introduced, including the principles, system setup, and the biomedical applications accomplished.

Original languageEnglish
Title of host publicationSecond Harmonic Generation Imaging
PublisherCRC Press
Number of pages42
ISBN (Electronic)9781439849156
ISBN (Print)9781439849149
StatePublished - 1 Jan 2016


Dive into the research topics of 'Combined SHG/THG Imaging'. Together they form a unique fingerprint.

Cite this