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Stimulated emission depletion (STED) microscopy has become a powerful imaging and localized excitation method, breaking the diffraction barrier for improved spatial resolution in cellular imaging, lithography, etc. Because of specimen-induced aberrations and scattering distortion, it is a great challenge for STED to maintain consistent lateral resolution deep inside specimens. Here we report on deep imaging STED microscopy using a Gaussian beam for excitation and a hollow Bessel beam for depletion (GB-STED). The proposed scheme shows an improved imaging depth of up to about 155 μm in a solid agarose sample, 115 μm in polydimethylsiloxane, and 100 μm in a phantom of gray matter in brain tissue with consistent super resolution, while standard STED microscopy shows a significantly reduced lateral resolution at the same imaging depth. The results indicate the excellent imaging penetration capability of GB-STED, paving the way for deep tissue super-resolution imaging and three-dimensional precise laser fabrication.

We report on a fast three dimension refractive index imaging of INS-1 cells based on optical holographic tomography. The imaging speed is boosted by simultaneously controlling the rotation of light and raw imaging logging. A fast and robust algorithm is used to mapping the data in frequency domain.

We report a collinear-chiral-SFG microscope for mapping chirality by utilizing longitudinally polarized optical field generated from vectorial beam, diffraction limited spatial resolution is demonstrated which conventional non-collinear chiral SFG imaging could not reach.

We demonstrate a strong enhancement of second harmonic generation based on a three-layered super absorbing metasurface consisting of a dielectric spacer layer sandwiched by an array of random metallic nanoparticles and a metal ground plate.

We report a Gauss-Bessel STED microscope for super-resolution deep imaging. Improved lateral resolution at 95μm-depth in agarose phantom of brain tissue is about 110nm, which is nearly 2-fold improvement on resolution comparing to conventional STED imaging.

We report on a holographic coherent anti-Stokes Raman scattering imaging by using polarization discrimination for nonresonant background suppression. With reduced polarization scrambling effect under weakly focused excitation, nonresonant background-free coherent Raman imaging is demonstrated. A fast chemically selective imaging is achieved in a three-dimensional volume of 70 μm ×70 μm ×100 μm in 2 s.

We report a STED microscope by using Bessel beam. Improved lateral resolution of deep-imaging at 84μm-depth was observed as 150nm, with comparison to a standard STED imaging resolution of 275nm measured at the same depth.

We develop a nonlinear beam propagation method for signal generation in inhomogeneous medium for wide-field nonlinear wave mixing microscope. Experimental results performed in wide-field coherent anti-Stokes Raman imaging have shown good agreement with the developed theory.

We propose and implement a wide-field vibrational phase contrast detection to obtain imaging of imaginary components of third-order nonlinear susceptibility in a coherent anti-Stokes Raman scattering (CARS) microscope with full suppression of the non-resonant background. This technique is based on the unique ability of recovering the phase of the generated CARS signal based on holographic recording. By capturing the phase distributions of the generated CARS field from the sample and from the environment under resonant illumination, we demonstrate the retrieval of imaginary components in the CARS microscope and achieve background free coherent Raman imaging.