SearcharxivSearch

arXiv · 2507.10129

Nonlinear Spectral Fusion Super-Resolution Fluorescence Microscopy based on Progressively Saturated Upconversion Nanoparticles

Abstract

Single-beam scanning microscopy (SBSM) is one of the most robust strategies for commercial optical systems. Although structured illumination combined with Fourier-domain spatial spectrum fusion can enhance SBSM resolution beyond the diffraction limit, a sophisticated detection system is still required to optimize both effective resolution and signal-to-noise ratio.Here, we report that the diverse nonlinear responses of upconversion nanoparticles can unlock a new mode of Computational Progressively Emission Saturated Nanoscopy (CPSN), which employs a single doughnut-shaped excitation beam assisted by deep learning to simplify conventional microscopy. By modulating the excitation power, the smooth transition of the point spread function (PSF) from doughnut-shaped to Gaussian can be achieved, allowing for accessing different spatial frequency components of the sample. Then, in order to enhance time resolution, the doughnut-shaped beam at low power and the saturated Gaussian-like image were predicted by the doughnut-shaped beam at low saturation threshold based on the power dependence curve. Furthermore, a deep recursive residual network (DRRN) is employed to fusion these progressively complementary spatial frequency information into a final super-resolved image that encompasses the full frequency wwinformation. This approach can achieve high-quality super-resolution imaging with a spatial resolution of 33 nm, corresponding to 1/29th of the excitation wavelength, 55 dB of SNR ratio contracted to 7 dB in Gaussian imaging and applicable to any wavelength. The unique combination of nonlinear saturation and deep learning computational reconstruction could open a new avenue for simplifying the optical system and enhancing imaging quality in single-beam super-resolution nanoscopy.

Explore related subjects

Keep this discovery

BibTeXRIS

Yongtao Liu, Tianxiao Wu, Xiao Zhou, Fan Wang. 2025-07-14. Nonlinear Spectral Fusion Super-Resolution Fluorescence Microscopy based on Progressively Saturated Upconversion Nanoparticles. https://arxiv.org/abs/2507.10129

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Two-step high-accuracy microwave frequency measurement and time-frequency analysis based on optical frequency combs

Broadband microwave frequency measurement and time-frequency analysis are crucial for applications such as electronic warfare. However, when it comes to ultra wideband signal analysis, traditional electronic methods have high analysis accuracy, but intrinsic electronic bottlenecks limit their real-time analysis. Here, we propose and experimentally demonstrate a two-step microwave frequency measurement and time-frequency analysis method based on optical frequency combs. The system first performs coarse frequency localization over the 0-40 GHz range using stimulated-Brillouin-scattering-assisted frequency-to-time mapping (FTTM) and dual-comb channelized reception. The dual-comb is then reapplied for downconverting the signal under test, followed by digital signal processing to achieve high-accuracy unambiguous frequency extraction. Experimental results show that the system achieves mean single-tone frequency measurement errors of less than 10 kHz over 0-40 GHz. We further experimentally measure multi-tone, linearly frequency-modulated, and V-shaped frequency-modulated signals, demonstrating the proposed method's capability for analyzing complex signals.

physics.optics

A Two-Mirror Faceted Projection System for EUV Lithography

We propose an all-reflective two-mirror projection system for extreme ultraviolet (EUV) lithography operating at exposure wavelengths of $13.5$~nm (Mo/Si) and $11.2$~nm (Ru/Be), delivering a fourfold ($4\times$) demagnification of the periodic mask pattern at a numerical aperture approaching unity ($\mathrm{NA}_{\max} \approx 0.993$). In contrast to conventional EUV projection objectives that incorporate 6--10 aspheric mirrors with an overall optical throughput of less than $15\%$, the proposed design redirects each accepted discrete spatial diffraction order scattered by the mask onto the wafer via a dedicated pair of planar mirror facets. The number of reflections is strictly fixed at two for all accepted orders, retaining $50$--$60\%$ of the power leaving the mask in each accepted order. We derive a spatial geometry providing rigorous optical path length equalization across all diffraction orders, thereby removing order-dependent propagation phase shifts. Individually optimized 30-bilayer Bragg multilayer coatings are designed for each facet using the transfer matrix method combined with global evolutionary optimization algorithms. The architecture is generalized to a three-dimensional vector formulation with a two-dimensionally periodic mask. Utilizing inverse lithography technology, Fourier parameterization, and a differentiable electromagnetic modal waveguide solver, we solve the synthesis problem for binary absorber masks (La absorber on a Ru/Be/Sr multilayer mirror). We demonstrate simulated aerial images of sub-10-nm features on the wafer (isolated peaks with a full width at half maximum (FWHM) of approximately $5.4$~nm and line pairs with a critical dimension of $6$~nm) and find that the two peaks remain resolved for the tested wafer defocus values from $0$ to $5$~nm along the $z$-axis.

physics.optics

Antimony for broadband nanophotonics across the ultraviolet, visible and infrared

Semimetal elemental antimony (Sb) nanostructures show great potential for applications where nanophotonic properties play a key role, such as phase-change optical memories, non-linear optical elements, photothermal therapy agents, photodetectors and photocatalysts. However, designing advanced Sb-based photonic devices critically requires an accurate and reliable knowledge of the optical response of bulk and nanoscale Sb. Herein, we report for the first time a fully consistent and accurately measured dielectric function for Sb nanoscale films in a wide spectral range from the ultraviolet to the far infrared (4 - 0.04 eV, i.e. ~ 0.3 - 30 $\mu$m), surpassing previous reports that explored a limited spectral range. It is found that the Sb spectral response is driven exclusively by giant interband transitions in the visible up to mid infrared (4 - 0.4 eV, i.e. ~ 0.3 - 3 $\mu$m), and that their contribution dominates over that of free carriers down to 0.12 eV (i.e. ~ 10 $\mu$m). Such spectral response enables Sb nanostructures to display spectrally selective and tunable nanophotonic resonances. First, we showcase interband plasmonic resonances in the visible-to-near infrared for Sb nanogratings. Second, we report giant refractive index dielectric resonances in the mid infrared for nanostructured Sb/dielectric/metal resonant cavities. These findings open a pathway to optimized planar Sb nanoscale designs enabling a tailored light-matter interaction, which will be useful for integrated data, telecom, medical, optoelectronic and energy conversion devices operating in a broad spectral range.

physics.optics