Fast interferometric second harmonic generation microscopy

Abstract

We report the implementation of fast Interferometric Second Harmonic Generation (I-SHG) microscopy to study the polarity of non-centrosymmetric structures in biological tissues. Using a sample quartz plate, we calibrate the spatially varying phase shift introduced by the laser scanning system. Compensating this phase shift allows us to retrieve the correct phase distribution in periodically poled lithium niobate, used as a model sample. Finally, we used fast interferometric second harmonic generation microscopy to acquire phase images in tendon. Our results show that the method exposed here, using a laser scanning system, allows to recover the polarity of collagen fibrils, similarly to standard I-SHG (using a sample scanning system), but with an imaging time about 40 times shorter.

Collagen chirality and three‐dimensional orientation studied with polarimetric second‐harmonic generation microscopy

“…Further, it was shown that the number of fibrils with different polarity in the tissue is equal . This behavior was also observed with interferometric SHG microscopy of collagenous tissues . Hence, we favor the third explanation.…”

Probing microtubules polarity in mitotic spindles in situ using Interferometric Second Harmonic Generation Microscopy

“…42). In short, the excitation source was a mode-locked Ti:Sapph laser (810 nm wavelength, 80 MHz repetition rate, ~150 fs pulses width, Tsunami, Spectra Physics) pumped by a 12 W Millenia Pro laser (Spectra Physics).…”

Elimination of imaging artifacts in second harmonic generation microscopy using interferometry

“…For a complete description of the I-SHG method and SHG set-up we refer to [23]. Importantly, an air immersion objective (UplanSApo 20X, NA 0.75, Olympus, Japan)) was used for excitation and the SHG emission was then collected with a 0.8NA objective (LUMPlanFLN, 40X, Olympus) to ensure that the numerical aperture is sufficiently high to collect the whole radiation pattern.…”

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