Temporal focusing-based multiphoton excitation fluorescence images with background noise cancellation via Hilbert-Huang transform

Abstract

Temporal focusing multiphoton excitation microscopy has wide field-of-view and optical sectioning. By using digital micromirror device, it provides patterned illumination. However, without filling the back aperture of objective lens, the axial confinement is limited to micron-meters, leading the out-of-focus fluorophores excited and image blurred. In this study, Hilbert-Huang transform is proposed to reduce the background noise. The empirical mode decomposition is first applied to disassemble the image into intrinsic mode functions and then reconstruct by Hilbert transform after diminishing background residues. The axial confinement can be enhanced from 2.79 mu m to 0.73 mu m with structure frequency in 1.06 mu m(-1).