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Xiaoqin Shen, PhD

PhD: National University of Singapore 2013

MSc: University of Science and Technology of China 2008

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Microcavity Nonlinear Photonics and Organic Photonics: Organic nonlinear photonics on the basis of high quality microcavities for compact and energy-efficient nonlinear photonics and optics applications, such as ultra-low threshold microlaser, frequency combs microgenerator, on-chip optical circuits, on-chip quantum processing, etc.

Organic Opical Materials: Fluorescent molecules, Nonlinear Optical Materials, electron defficient material, photo-responsive materials, etc.

Nanomedicine, Optical Bio-imaging and Bio-sensing: New optical probes for bio-sensing, bio-imaging, noninvasive cancer therapy, imaging-guided therapy, etc.

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Current Projects:

1. Organic hybrid ultra-high quality microcavities for nonlinear photonics. Coherent frequency generators are an enabling platform in basic science and applied technology. We reported a new strategy to fabricate near-infrared frequency combs based on combining high-Q microcavities with monomolecular layers of highly nonlinear small molecules. The functionalized microcavities demonstrate high-efficiency parametric oscillation in the near-IR and generate primary frequency combs with 0.88-mW thresholds, improving optical parametric oscillation generation over nonfunctionalized devices by 1000x. This organic-inorganic approach enables otherwise unattainable performance and will inspire the next generation of integrated photonic device platforms.(Science Advances, 2018)

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2. Organic nonlinear optical materials

3. Nonlinear optical molecular probes for neuron and tissue imaging

 

Past Projects:

1. Fluorescence resonance energy transfer (FRET) based novel nano-photosensitizers for two-photon photodynamic therapy. Using femtosecond laser spectroscopy and microscopy, we systematically studied the photophysical properties and energy transfer processes conjuagated polymer based nanoparticles (CPNPS). We, for the first time, discovered that the conjugated polymers as efficient two-photon light harvesting matrix can effectively enhance singlet oxygen generation ability of the CPNPS by an enhancement factor of 1000x, via a series of energy transfer processes. The CPNPS were further demonstrated for cancer cell-targeting two-photon imaging and laser therapy. (Eur. J. Chem., 2015; Nanoscale, 2011; Langmiur, 2011)

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2.  Fluorescent Conjugated Polymers for Simultaneous Two-Photon (nonlinear optical) Imaging and Photodynamic Therapy. Using ultrafast laser spectroscopy, we studied the two-photon photophysical and photochemical properties of a series of new conjugated polymers. We found that by introducing a pair of cyano group to the polymer backbone, the two-photon absorption properties, fluoresence quantum yield and two-photon singlet oxygen generation abilities are all enhanced! The polymers were demonstrated as promising nano-agents for imaging-guided two-photon cancer therapy. (Adv. Opt. Mater., 2013; macromolecules, 2011)

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3. Switchable two-photon Cell Membrance probe. Two-photon molecular probes were designed to be able to detect transmembrance enzymetic activitives. After triggered by UV light,the "smart" probe specifically locating on cell membrance can turn on its functionality to light up targeted enzymes. It enable cell biologist to image and study cellular enzymetic activies. (Angew. Chem. Int., 2012)

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4. Photo-active organic materials and polymer single crystal. Chemical struture and molecular cystalline packing both play critical role in new materials development. We designed and synthesized a series of novel S-indance and bis-indene aromatric molecules and explored their unique optical, electrical and crystalline properties. Single crystal-to-single crytal light-triggered topologial polymerization was disovered in the new developed photo-active materials. (Science, 2014; J. Mater. Chem. C, 2016)

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5. Nonlinear optical dendrimers and novel photo-responsive nanomaterials.(Macromolecules, 2008; J. Am. Soc. Chem., 2010)

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