Xuchen Shan

• Doctor of Philosophy
• Assistant Professor at Beihang University

Optical tweezers are widely used in materials assembly¹, characterization², biomechanical force sensing3,4 and the in vivo manipulation of cells⁵ and organs⁶. The trapping force has primarily been generated through the refractive index mismatch between a trapped object and its surrounding medium. This poses a fundamental challenge for the optical t...

Point spread function (PSF) engineering by an emitter's response can code higher‐spatial‐frequency information of an image for microscopy to achieve super‐resolution. However, complexed excitation optics or repetitive scans are needed, which explains the issues of low speed, poor stability, and operational complexity associated with the current las...

Multiphoton fluorescence microscopy (MPM), using near infrared excitation light, provides increased penetration depth, decreased detection background, and reduced phototoxicity. Using stimulated emission depletion (STED) approach, MPM can bypass the diffraction limitation, but it requires both spatial alignment and temporal synchronization of high...

Interferometric Scattering Microscopy Rayleigh scattering of the nanoparticles can be engineered by doping lanthanide ions, which is based on the enhanced polarizability of the nanoparticles when the excitation wavelength matches the ion resonance frequency of the lanthanide ions. More details can be found in article number 2203354 by Baolei Liu, C...

Super‐resolution fluorescence microscopy is of great interest in life science studies for visualizing subcellular structures at the nanometer scale. Among various kinds of super‐resolution approaches, image scanning microscopy (ISM) offers a doubled resolution enhancement in a simple and straightforward manner, based on the commonly used confocal m...

Precise force measurement is critical to probe biological events and physics processes, spanning from molecular motor’s motion to the Casimir effect, as well as the detection of gravitational waves. Yet, despite extensive technological developments, the three-dimensional nanoscale measurement of weak forces in aqueous solutions still faces major ch...

Ultraviolet (UV) imaging enables a diverse array of applications, such as material composition analysis, biological fluorescence imaging, and detecting defects in semiconductor manufacturing. However, scientific-grade UV cameras with high quantum efficiency are expensive and include complex thermoelectric cooling systems. Here, we demonstrate a UV...

Lensless diffuser camera is a novel and flexible approach to capture object’s images. Here, we propose a compact spectral and polarization diffuser camera (SPDC) enabled by a diffuser and a complementary metal oxide semiconductor (COMS) sensor. We demonstrated SPDC to reconstruct images with spectral and polarization by simulations. It can be highl...

Super-resolution microscopy provides a high spatial resolution that is beyond the diffraction barrier and can visualize nano-sized structures and interactions in biological and material study. In recent years, lanthanide-doped upconversion nanoparticles (UCNPs) that can upconvert the near-infrared (NIR) excitation photons to visible emission photon...

Optical multiplexing for nanoscale object recognition is of great significance within the intricate domains of biology, medicine, anti‐counterfeiting and microscopic imaging. Traditionally, the multiplexing dimensions of nanoscopy are limited to emission intensity, colour, lifetime, and polarization. Here we propose a novel dimension, optical nonli...

To minimize and control the transmission of infectious diseases, a sensitive, accurate, rapid, and robust assay strategy for application on-site screening is critical. Here, we report single-molecule RNA capture-assisted digital RT-LAMP (SCADL) for point-of-care testing of infectious diseases. Target RNA was captured and enriched by specific captur...

Ultraviolet (UV) imaging enables a diverse array of applications, such as material composition analysis, biological fluorescence imaging, and detecting defects in semiconductor manufacturing. However, scientific-grade UV cameras with high quantum efficiency are expensive and include a complex thermoelectric cooling system. Here, we demonstrate a UV...

Manufacturing sharp features is one of the most desired requirements for lithography. Here, we demonstrate a dual-path self-aligned polarization interference lithography (Dp-SAP IL) for fabricating periodic nanostructures, featuring high-steepness and high-uniformization. Meanwhile, it can manufacture quasicrystals with adjustable rotation symmetry...

In this paper, we present a dual-mode adaptive singular value decomposition ghost imaging (A-SVD GI), which can be easily switched between the modes of imaging and edge detection. It can adaptively localize the foreground pixels via a threshold selection method. Then only the foreground region is illuminated by the singular value decomposition (SVD...

In this paper, we present a dual-mode adaptive singular value decomposition ghost imaging (A-SVD GI), which can be easily switched between the modes of imaging and edge detection. It can adaptively localize the foreground pixels via a threshold selection method. Then only the foreground region is illuminated by the singular value decomposition (SVD...

In this paper, we present a dual-mode adaptive singular value decomposition ghost imaging (A-SVD GI), which can be easily switched between the modes of imaging and edge detection. It can adaptively localize the foreground pixels via a threshold selection method. Then only the foreground region is illuminated by the singular value decomposition (SVD...

Nanoscale weak force sensing in aqueous solution is of great interest to researchers from broad areas, including physics and biology. Here we developed a video tracking-based optical tweezers calibration method that enables the detection of the trap stiffness for low refractive index nanoparticles. We found that under resonance conditions, doping l...

Precise force measurement is critical to probing biological events and physics processes, spanning from molecular motor’s motion to the Casimir effect ¹ and the detection of gravitational wave ² . Yet, despite extensive technology developments, the 3D nanoscale measurement of weak forces in aqueous solutions poses a significant challenge. Technique...

Single-beam super-resolution microscopy, also known as superlinear microscopy, exploits the nonlinear response of fluorescent probes in confocal microscopy. The technique requires no complex purpose-built system, light field modulation, or beam shaping. Here, we present a strategy to enhance this technique's spatial resolution by modulating excitat...

Light scattering from nanoparticles is significant in nanoscale imaging, photon confinement. and biosensing. However, engineering the scattering spectrum, traditionally by modifying the geometric feature of particles, requires synthesis and fabrication with nanometre accuracy. Here it is reported that doping lanthanide ions can engineer the scatter...

Single-beam super-resolution microscopy, also known as superlinear microscopy, exploits the nonlinear response of fluorescent probes in confocal microscopy. The technique requires no complex purpose-built system, light field modulation, or beam shaping. Here, we present a strategy to enhance spatial resolution of superlinear microscopy by modulatin...

The diverse photoresponses from different energy levels in lanthanide‐doped nanoparticles enables simultaneous generation of multiple point‐spread functions with one doughnut‐shaped excitation beam. In article number 2008847, Fan Wang, Dayong Jin, and co‐workers explore a new imaging modality to extend the capabilities of the engineered point‐sprea...

Point spread function (PSF) engineering by emitter's response can code higher spatial frequency information of an image for microscopy to achieve super-resolution. However, complexed excitation optics or repetitive scans are needed, which explains the issues of low speed, poor stability and operational complexity associated with the current laser s...

To simplify the reconstruction algorithms in ghost imaging, we present a feedback-based approach to reduce reconstruction times. We introduce a genetic algorithm to optimize the illumination patterns in real-time to match with the object's shape.

Correction for ‘Video-rate upconversion display from optimized lanthanide ion doped upconversion nanoparticles’ by Laixu Gao et al. , Nanoscale , 2020, DOI: 10.1039/d0nr03076g.

We developed a video-rate upconverting display system with much enhanced brightness. The integral emission intensity of the single Volumetric displays that create bright image points within a transparent bulk is one of the most attracting technologies in everyday life. Lanthanide ions doped upconversion nanoparticles (UCNPs) is an promising lumines...

Video-rate super-resolution imaging through biological tissue can visualize and track biomolecule interplays and transportations inside cellular organisms. Structured illumination microscopy allows for wide-field super resolution observation of biological samples but is limited by the strong extinction of light by biological tissues, which restrict...

Video-rate super-resolution imaging through biological tissue can visualize and track biomolecule interplays and transportations inside cellular organisms. Structured illumination microscopy allows for wide-field super resolution observation of biological samples but is limited by the strong absorption and scattering of light by biological tissues,...

In article number 1905572, Fan Wang and co‐workers develop near‐infrared Bessel‐beam emission saturation nanoscopy to simultaneously tackle the problems in light absorption and scattering for biological tissues, enabling the tracking of single nanoparticles inside a multicellular tumor spheroid in the depth over 55 µm with an imaging resolution of...

Cancer spheroids have structural, functional, and physiological similarities to the tumor, and have become a low‐cost in vitro model to study the physiological responses of single cells and therapeutic efficacy of drugs. However, the tiny spheroid, made of a cluster of high‐density cells, is highly scattering and absorptive, which prevents light mi...

Bright and photo-stable luminescent nanoparticles held great potential for bioimaging, long-term molecular tracking. Rare-earth-doped upconversion nanoparticles (UCNPs) have been recently discovered with unique properties for Stimulated Emission Depletion (STED) super-resolution microscopy imaging. However, this system strictly requires optical ali...