Near-infrared Region Research Articles

Octahedral Hexanuclear Rhenium Cluster Dimers Bridged by Pyrazine or 4,4'-Bipyridine with 23- and 24-Electron Configurations.

New pyrazine (pz)- and 4,4'-bipyridine (4,4'-bpy)-bridged octahedral hexanuclear rhenium(III) cluster dimers, [{Re6(μ3-S)8Cl5}2(μ-L)]6- (L = pz, [1]6-; L = 4,4'-bpy, [2]6-), with 2 × 24 d-electrons {Re6(24e)}2 were obtained in a single-step reaction via photoirradiation of [Re6(μ3-S)8Cl6]4- with L in a 2:1 ratio at room temperature. The {Re6(23e)}2 dimers, [{Re6(μ3-S)8Cl5}2(μ-L)]4- (L = pz, [1']4-; L = 4,4'-bpy, [2']4-), were synthesized through two-electron oxidation of [1]6- and [2]6-, respectively. The single-crystal X-ray structures of [1]6- and [1']4- were determined, revealing structural distortion of the Re6 core of [1']4- due to the Jahn-Teller effect. The cyclic voltammograms of [1]6- and [2]6- showed two steps of one-electron redox processes attributable to Re6(23e)Re6(24e)/{Re6(24e)}2 and {Re6(23e)}2/Re6(23e)Re6(24e), respectively. The separation between the two redox potentials is small (0.056 V for [1]6- and 0.039 V for [2]6-). The magnetic susceptibilities of [1']4- and [2']4- were almost temperature-independent, with values of 2.98 and 2.85 μB, respectively, indicating paramagnetism. These results suggest weak electronic interaction between two cluster units bridged by pz or 4,4'-bpy in the intercluster mixed valence state. The compounds [1]6- and [2]6- show photoluminescence in the near-infrared region at 296 K in the solid state.

Toward Ultra-High Sensitivity Optical Thermometers and Bright Yellow LEDs Based on Phonon-Assisted Energy Transfer in Rare Earth-Doped La2ZnTiO6 Double Perovskite.

Double perovskites, a class of ceramic oxides with unique crystal structures and diverse physical properties, show promise for various technological applications including solar cells, photodetectors, and light-emitting diodes (LEDs). Despite limited research on rare earth-doped double perovskites, leveraging their ultrahigh luminous efficiency to achieve bright yellow LED emission and addressing energy transfer challenges between Yb3+ and Nd3+ ions in double perovskite La2ZnTiO6 with moderate phonon energy are explored in this work. Through phonon-assisted energy transfer, an ultrasensitive optical thermometer covering a wide temperature range is developed by utilizing the different temperature responses of Er3+ emission in the visible light region and Nd3+ emission in the near-infrared region based on the luminescence intensity ratio (LIR). All the results demonstrate that the rare earth (Yb-Er, Yb-Nd, and Yb-Nd-Er)-doped La2ZnTiO6 phosphors can be effectively utilized for ultrabright LED illumination and ultrahigh sensitivity self-calibrated temperature sensing. This research underscores the significance of phonon-assisted energy transfer in improving material properties and provides valuable insights for the advancement of multifunctional materials.

Synthesis and photophysical properties of symmetrical tetraaryltetranaphtho[2,3]porphyrin derivatives

The discovery of new photosensitizers with strong absorption near-infrared region, obvious fluorescence emission, and high reactive oxygen generation ability has attracted great attention as optical agents in life science and material industry. Herein a series of meso-tetraaryltetranaphtho[2,3]porphyrins (Ar 4TNPs) with different substitutions were designed and synthesized. They had strong absorptions at ∼730 nm and fluorescence emission at ∼760 nm after excitation with ∼503 nm light. All compounds possessed excellent reactive oxygen species (ROS) generation ability. The singlet oxygen generation rate of compound 10m (meso-5,10,15,20-tetra[2-(2-hydroxyethoxy)ethylbenzoate]tetrana-phthoporphyrin) is 0.1898 s−1 with a Φ△ value of 0.73, which is significantly higher than that of verteporfin. Therefore, Ar4TNPs have great potential as an effective optical material, bio-tracker, and photodynamic drug candidate.

Coherent coupling of localized surface plasmons and surface plasmons in borophene-based metamaterial

The strong coherent coupling in different electromagnetic modes can control the light-matter interaction more conveniently. Here, we theoretically researched the hybridization between the borophene surface plasmon (BSP) mode and the borophene localized surface plasmon (BLSP) mode in borophene grating structure. This coupling effect leads to the emergence of multiple hybrid modes. The absorption spectra of the system are investigated through finite difference time domain (FDTD) simulation and coupled oscillator model (COM). Results show that the coherent coupling of BSP and BLSP can be achieved by adjusting the carrier density of the borophene gratings. A Rabi splitting effect with frequency of 21.6 THz can be observed. Furthermore, we investigated the effects of geometric structural parameters, incident angle, and relaxation time on the correlated coupling spectra. Our work may deepen the understanding of light–matter interactions and provide a reference for borophene-based active photonic devices in the near-infrared region.

Boosted luminescence of chiral nanophosphors with circularly polarized luminescence

Achieving strong circularly polarized luminescence (CPL) responses in chiral inorganic materials is a challenge. Our study reports a synthesis of bismuth bromide oxybate-based inorganic nanomaterials that have been modified with chiral sugar alcohols (D/L-BYE) co-doped with Er3+ and Yb3+. Chiral molecules are used as inducers to preferentially grow the materials towards specific chirality. The Er3+, Yb3+ co-doped chiral sugar alcohol modified BiOBr has stronger luminescence intensity of up-conversion and the near-infrared second region (NIR II) under the excitation of 980 nm. It has been demonstrated that the enhancement of near-infrared and visible luminescence is attributable to electromagnetic field-induced acceleration of radiative excursion and Mie scattering effects. The study proposes a novel approach to simultaneously enhance the up/down conversion luminescence of chiral inorganic nanomaterials doped with rare earth ions. Meanwhile, this material exhibits strong circularly polarized luminescence properties in the visible range, which has great application potential in chiral optics and other fields.

Near-infrared light-promoted engineering oxygen vacancy of Fe3Ov-Mo/P nanozyme for sensitive detection of glyphosate

The rapid and sensitive detection of glyphosate herbicide in agricultural products is urgent need. Herein, we develop a photosensitive Fe3Ov-Mo/P nanozyme with defect-rich rough surface by the co-precipitation method. In particular, the Fe3Ov-Mo/P nanozyme with high-percentage oxygen vacancy (OV) defects and rough surface exhibited superior peroxidase (POD)-like activity and kinetics. More intriguingly, Fe3Ov-Mo/P nanozyme with strong optical absorption in near-infrared (NIR) region showed excellent light-promoted POD-like activity. It was found that the defect-rich rough surface is conducive to the adsorption of glyphosate to inhibit the POD-like activity of Fe3Ov-Mo/P. Under near-infrared laser irradiation, the inhibitory effect of glyphosate on the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by Fe3Ov-Mo/P was increased by 2.64 times. A colorimetric platform was developed for the detection of glyphosate with a low detection limit of 0.032 mg L-1 and good selectivity. The method was used to determine the residual glyphosate in coffee, and the recovery efficiency was between 91.20–104.00 %. This work that combines the advantage of defect engineering and NIR provides a strategy for developing high-active nanozyme in pesticide assay.

Saturable absorption properties of mixed lead-tin halide perovskites and their application in near-infrared ultrafast lasers

Mixed lead–tin halide perovskites, as highly sensitive materials in the near-infrared region, hold significant potential for optoelectronic device applications. Here, mixed lead–tin halide perovskite saturable absorbers (SAs) have been developed by coupling with the side-polished surfaces of the single-mode fibers and excellent saturable absorption effects of the mixed lead–tin halide perovskite SAs have been demonstrated in the near-infrared region. By constructing the in-gap site assisted carrier transfer mode, the saturation absorption process of the mixed lead–tin halide perovskite SAs can be well explained, in which defects as in-gap sites can help the photon-generated carriers transfer into the conduction band and promote the Pauli-blocking-induced absorption bleaching in the SA. Moreover, ytterbium-doped fiber lasers based on perovskite SAs have been fabricated, and mode-locked operations at 1040 nm are achieved using the mixed lead–tin halide perovskite SA, generating ultra-short pulses with a pulse width of 683 fs, 3 dB bandwidth of 4.88 nm, signal-to-noise ratio exceeding 49.74 dB, and a repetition rate of 3.74 MHz. Our findings demonstrate that the mixed lead–tin halide perovskite SAs have excellent optical modulation capability and promising applications in the field of ultrafast photonics.

High performance ambipolar response photodetectors based on ReS2/PdSe2 van der Waals heterostructures

Anomalous negative photoresponse in a photodetector where the current is reduced under light illumination holds great potential in the application of next-generation novel and multifunctional optoelectronic devices. Until now, the figure of merits for negative photodetectors, such as responsivity and response speed, still exhibit unsatisfactory performance when compared to their positive counterparts. In this work, an unique gate voltage-dependent ambipolar-response photodetector based on the ReS2/PdSe2 heterostructure with excellent characteristics are prepared and investigated systematically. The evolution for concentration of hole in PdSe2 by gate voltage and the trap states existed at the surface and interface play a dominant role in the transition of negative to positive response. The negative photoresponse performances in terms of responsivity, external quantum efficiency (EQE), and response speed under 638 nm light illumination, are as high as about 532 A/W, 105%, and as fast as 7.9/8.7 µs, respectively. Meanwhile, the corresponding values of the positive response also reach to ∼10.5 A/W, ∼2069 %, and ∼30 µs, respectively, demonstrating the superiority of this heterostructure at ambipolar response. In addition, a similar phenomenon is also observed at the near-infrared region (980 nm). The discovery of these results signifies a pronounced breakthrough in the field of ambipolar photodetectors, thereby paving the way for future advancements in optoelectronic applications.

Synthesis of Chlorophylls-Doped Guanine Crystals with High Reflection and Depolarization for Green Camouflage Coating.

Hyperspectral imaging technology can record the spatial and spectral information of the targets and significantly enhance the levels of military reconnaissance and target detection. It has scientific importance to mimic "homochromatic and homospectral" camouflage materials that have hyperspectral similarity with the green vegetation, one of the most common natural backgrounds. It is a big challenge to exquisitely simulate the spectral of green vegetation in visible and near-infrared windows because of the slight differences between the artificial green dyes and vegetation, the instability of chlorophylls, and the easy loss of hydroxide bands due to the loss of water from the camouflage materials. Herein, a novel kind of biomimetic material of green vegetation was designed through the incorporation of chlorophylls into the crystal lattices of single-crystalline anhydrous guanine microplates for the first time. The synthesized chlorophylls-doped anhydrous guanine crystals exhibit high reflectance intensity and depolarization effect, thus can be applied as biomimetic camouflage materials that mimic green vegetation with high reflectivity and low polarization in the visible and near-infrared regions. The factors influencing the formation of dye-doped organic crystals under mild conditions were thoroughly investigated and the characterizations using electron microscopies and fluorescence confocal laser scanning microscopy clearly confirm the occlusion of chlorophylls into the crystal lattices of guanine crystals. The thermal stability experiments clearly indicate that the chlorophylls-doped guanine crystals possess long-term stability at high temperature. This study provides a new strategy for the synthesis of multifunctional materials comprised of organic crystals.

Pd octahedra nanocubes mediated photo-fenton catalytic performance for sustainable degradation of methylene blue

This research utilized a typical solvothermal approach, by employing Na2PdCl4 as the synthetic precursor, L-ascorbic acid (AA) as the reductant agent, and polyvinylpyrrolidone (PVP) as the practical surfactant, palladium (Pd) octahedra was finally effectively synthesized by the hydrothermal and solvothermal methods. Subsequently, characterizations of Pd octahedra were conducted by using TEM, XPS, XRD, and other analytical methods. Whereafter, Pd octahedra displayed a consistent shape and size, featuring a distinctive tip-shaped structure, which conferred upon them outstanding optical absorption properties within the near-infrared (NIR) region. Consequently, under NIR laser exposure, Pd octahedra could elevate local reaction temperature via in-situ photothermal conversion, thereby stimulating the formation of active sites of Fenton catalysts. The Photo-Fenton catalytic activity of Pd octahedra was investigated by using methylene blue (MB) as a model pollutant. The degradation efficiency of MB reached 94.8 % within 35 min under 808 nm laser irradiation, and the removal rate of MB by Pd octahedra could still reach more than 90 % after five cycles of use. All the results manifest that Pd octahedra exhibit excellent purification performance for MB dyestuff wastewater.

Influence of Spotted Lanternfly (Lycorma delicatula) on Multiple Maple (Acer spp.) Species Canopy Foliar Spectral and Chemical Profiles

Invasive species have historically disrupted environments by outcompeting, displacing, and extirpating native species, resulting in significant environmental and economic damage. Developing approaches to detect the presence of invasive species, favorable habitats for their establishment, and predicting their potential spread are underutilized management strategies to effectively protect the environment and the economy. Spotted lanternfly (SLF, Lycorma delicatula) is a phloem-feeding planthopper native to China that poses a severe threat to horticultural and forest products in the United States. Tools are being developed to contain the spread and damage caused by SLF; however, methods to rapidly detect novel infestations or low-density populations are lacking. Vegetation spectroscopy is an approach that can represent vegetation health through changes in the reflectance and absorption of radiation based on plant physiochemical status. Here, we hypothesize that SLF infestations change the spectral and chemical characteristics of tree canopies. To test this hypothesis, we used a full range spectroradiometer to sample canopy foliage of silver maple (Acer saccharinum) and red maple (Acer rubrum) trees in a common garden in Berks County, Pennsylvania that were exposed to varying levels of SLF infestation. Foliar spectral profiles separated between SLF infestation levels, and the magnitude of separation was greater for the zero-SLF control compared with higher infestation levels. We found the red-edge and portions of the NIR and SWIR regions were most strongly related to SLF infestation densities and that corresponding changes in vegetation indexes related to levels of chlorophyll were influenced by SLF infestations, although we found no change in foliar levels of chlorophyll. We found no influence of SLF densities on levels of primary metabolites (i.e., pigments, nonstructural carbohydrates, carbon, and nitrogen), but did find an increase in the phenolic compound ferulic acid in response to increasing SLF infestations; this response was only in red maple, suggesting a possible species-specific response related to SLF feeding. By identifying changes in spectral and chemical properties of canopy leaves in response to SLF infestation, we can link them together to potentially better understand how trees respond to SLF feeding pressure and more rapidly identify SLF infestations.

Nitrogen-doped bismuth ferrite nanozymes: Tailored electronic structure for organic pollutant degradation

The insufficient catalytic activity and non-recyclability of nanozymes are major obstacles for nanozyme-mediated water purification. Since electronic transfer is the basic essence of catalysis-mediated redox reactions, this research reveals that meticulous tuning of the electronic structure of magnetic bismuth ferrite (BiFeO3) through nitrogen doping, allows for excellent performance in organic pollutants degradation in water (including dyestuff and antibiotics), along with magnet separation-mediated recyclability. Mechanically speaking, nitrogen-doping rational optimize their peroxidase-like activity by increasing the electron density of the Fe-N active center, meanwhile, the tailored bandgap significantly enhances the full-spectrum absorption, especially in the near-infrared region (NIR). Consequently, a light-enhanced N-doped BiFeO3 nanozyme has been engineered to generate excessive reactive oxygen species (14.63-fold in total) for pollutants degradation with recyclable capacity, 94.27 % for Methylene Blue and over 60 % for multiple antibiotics. This study underscores the efficacy of fine-tuning the electronic structure in enhancing the catalytic performance of nanozymes for organic pollutants removing.

Optimum Solar Cell Power Conversion Efficiency-Based Patterned Planar Solar Surface Morphology with Various Solar Cell Absorber Structures

This paper simulated the optimum solar cell power conversion efficiency-based planar solar surface morphology with various solar cell absorber structures. The spectral light intensity, reflected, absorbed, and transmission coefficients versus wavelength band spectrum varied from 300[Formula: see text]nm to 1300[Formula: see text]nm through the visible to near-infrared regions. The optimum solar cell performance parameters or key parameters are studied with different solar cell structure designs based on different surface contact and back contact layers. Cumulative generation current, cumulative electron–hole pair generation rate and electron–hole pair generation rate are clarified versus substrate depth for various solar cell structure designs. The absorbed current in substrate is optimized for various solar cell structure designs. Maximum power voltage and current are also optimized for the proposed solar cell structure design. The effective solar cell power efficiency is also demonstrated based on the optimized maximum power current and maximum power voltage.

Cisplatin Encapsulated Plasmonic Blackbodies for NIR Light Activatable Chemo-Phototherapy and Reduction of 4-Nitrophenol.

Cisplatin (CDDP) is an FDA-approved chemotherapeutic drug used for treating various solid tumors. Despite of its effectiveness towards chemotherapy, it faces several challenges, such as multi-drug resistance (MDR) and significant damage to the normal tissues. To address these challenges, various nanoformulations were developed to improve the delivery and safety of CDDP. One of the limitation in these CDDP loaded nanoformulations is that the effective CDDP loading concentrations are very poor. Therefore, this leaves a grand challenge to develop an effective strategy to carry higher concentrations of CDDP molecules, and also simultaneously exhibit very unique properties. Herein, we have developed an one-pot synthesis of Cisplatin encapsulated Plasmonic blackbody (CiP), which offers a double play for near infrared (NIR) light activatable chemo-photothermal therapy in destructing cancer cells as well as mediate catalytic reduction of 4-nitrophenol (4-NP). The CiP nanoformulation exhibits superior light absorbing capabilities in the NIR region with an appreciable photothermal conversion efficiency of 41 %. Further, NIR light activatable combinatorial therapeutic approach of CiP was demonstrated against ovarian cancer cells and as a catalyst for the reduction of model pollutant 4-nitrophenol. Our findings highlight the potential of CiP as a versatile platform for light-activated combinatorial cancer therapy and environmental pollutant remediation.

High-Verdet Constant and Low-Optical Loss Tb3+ Doped Magnetite Nanoparticles.

Magneto-optical (MO) polymer nanocomposites have emerged as alternatives to conventional MO crystals, particularly in nanophotonics applications, thanks to their better processing flexibility and superior Verdet constants. However, a higher Verdet constant commonly comes with excessive optical loss due to increased absorption and scattering, resulting in a constant or reduced figure-of-merit (FOM) defined as the Verdet constant over optical loss. By doping magnetite (Fe3O4) nanoparticles with Tb3+ ions, we report a new strategy to enhance the Verdet constant without increasing the optical loss. The Fe3O4:Tb3+ nanocomposite is one of a kind that simultaneously achieves a state-of-the-art Verdet constant of 5.6 × 105 °/T·m and a state-of-the-art FOM of 31°/T in the near-infrared region.

Ultra-low-cost and high-fidelity NIR-II confocal laser scanning microscope with Bessel beam excitation and SiPM detection.

Confocal laser scanning microscopy (CLSM) is one of the most important imaging tools in the biomedical field, and near-infrared-II (NIR-II, 900-1700nm) fluorescence imaging technology has also made fruitful research progress in deep imaging in recent years. The NIR-II based CLSM has problems such as an expensive detector and reduced image resolution caused by long wavelength excitation. Here, by simultaneously using a low-cost silicon photomultiplier (SiPM) as a detector and a Bessel beam as an excitation, we developed an ultra-low-cost and high-fidelity NIR-II confocal laser scanning microscope. The use of SiPM reduces the cost of the NIR-II fluorescence detection module in CLSM, while enabling the detection of ultra-broadband fluorescence signals spanning visible to NIR-II regions. The introduction of the Bessel beam compensates to some extent for the weakening of spatial resolution caused by the increase in the wavelength of light in the NIR region. Experimental results show that the use of the Bessel beam can improve the resolution by 12% when observing thin samples. With the increase of sample thickness, the imaging resolution of the Bessel beam at NIR-II wavelengths is better than that of the Gaussian beam at NIR-I wavelengths at the penetrable depth of the NIR-I light. At deeper depths, the imaging resolution and imaging depth of Bessel beam CLSM is superior to Gaussian beam CLSM at the same excitation power.

High‐Order Nonlinear Frequency Conversion in Transparent Conducting Oxide Thin Films

AbstractThe study of conductive oxides has gained momentum within the photonics community due to their unique linear and nonlinear optical properties. Despite recent experiments reporting on high harmonic generation from thin films, the optical/electronic behavior of these compounds at the nanoscale is still not fully understood due to the lack of a suitable theoretical model. In the present work, aluminum zinc oxide is excited near its epsilon‐near‐zero crossing point using incident femtosecond pulses having peak power densities in the 1 TW cm−2 range. A relatively efficient frequency up‐conversion including even and odd harmonics up to the seventh order is observed. A hydrodynamic‐Maxwell theoretical approach is adopted, capable of simultaneously taking into account linear and nonlinear dispersions, nonlocal effects, surface, magnetic, and bulk nonlinearities in a spectral region that spans over two and a half octaves from the UV to the NIR region. The study enables a deeper understanding of the fundamental material parameters regulating optical nonlinearities, providing important insights to engineer this class of materials for applications in sensing, ultra‐fast physics, and spectroscopy.

N,C,N-Pincers in Platinum Bimetallic Complexes: Influence of the Pincer and Bridging Ligands on the Metal-Metal Bond and the Photophysical Properties.

Precursors PtCl{κ3-N,C,N-[py-C6HMe2-py]} (1), PtCl{κ3-N,C,N-[py-O-C6H3-O-py]} (2), Pt(OH){κ3-N,C,N-[py-C6HMe2-py]} (3), and Pt(OH){κ3-N,C,N-[py-O-C6H3-O-py]} (4) were used to prepare d8-platinum bimetallic complexes. Precursors 1 and 2 react with AgBF4 and 7-azaindole (Haz) to give [Pt{κ3-N,C,N-[py-C6HMe2-py]}{κ1-N-[Haz]}]BF4 (5) and [Pt{κ3-N,C,N-[py-O-C6H3-O-py]}{κ1-N-[Haz]}]BF4 (6) and 3 and 4 with indolo[2,3-b]indole (H2ii) to generate Pt{κ1-N-[Hii]}{κ3-N,C,N-[py-C6HMe2-py]} (7) and Pt{κ1-N-[Hii]}{κ3-N,C,N-[py-O-C6H3-O-py]} (8). Subsequent addition of 3 and 4 to 5-7 affords bimetallic derivatives [{Pt[κ3-N,C,N-(py-C6HMe2-py)]}2{μ-N,N-[az]}]BF4 (9), [{Pt[κ3-N,C,N-(py-O-C6H3-O-py)]}2{μ-N,N-[az]}]BF4 (10), and {Pt[κ3-N,C,N-(py-C6HMe2-py)]}2{μ-N,N-[ii]} (11). X-ray structures of 9-11 reveal separations between the metals in sequence 9 (3.0515(4) Å) < 10 (3.2689(9) Å) < 11 (3.2949(2) Å). DFT calculations support σ overlap of the dz2 orbitals of platinum atoms, for 9 and 10. Accordingly, their absorption spectra show a MMLCT transition. Complex 9 is a red emitter. The excited state has 3MMLCT characteristics and a Pt-Pt separation of 2.763 Å. Complex 11 is a dual emitter in the red and NIR regions, in solid. Both excited states have a 3LC/LMCT characteristic and platinum-platinum separations of 3.290 and 3.202 Å. Intermediate 5 is a green emitter that achieves quantum yields close to unity, when diluted in PMMA and 1,2-dichloroethane at low concentrations.

M-Pyripentaphyrins(1.0.0.0.0): BIII Complexes and β-β Directly Linked Dimers.

m-Pyripentaphyrins(1.0.0.0.0) were synthesized by Suzuki-Miyaura coupling of 3,5-bis(5-borylpyrrol-2-yl)-BODIPY with 2,6-dibromopyridine. Upon treatment with PhBCl2, pyripentaphyrin 1 provided mono- and bis-BIII complexes sequentially. The Mono-BIII complex shows a distorted tetrahedral coordinated BIII with a σ-phenyl ligand on the BIII and the bis-BIII complex shows an additional distorted tetrahedral coordinated BIII with a B-H bond. Bromination of the pyripentaphyrins with N-bromosuccinimide (NBS) resulted in regioselective formation of 8-bromopyripentaphyrins, which were dimerized to 8,8'-linked dimers by reductive coupling with Ni(cod)2. While all these pyripentaphyrins are nonaromatic, they exhibit characteristic broad absorption bands at long wavelength near the NIR region, indicating the presence of effective macrocyclic conjugation.

Coumarin-Based Photodegradable Hydrogels Enable Two-Photon Subtractive Biofabrication at 300 mm s-1.

Spatiotemporally controlled two-photon photodegradation of hydrogels has gained increasing attention for high-precision subtractive tissue engineering. However, conventional photolabile hydrogels often have poor efficiency upon two-photon excitation in the near-infrared (NIR) region and thus require high laser dosage that may compromise cell activity. As a result, high-speed two-photon hydrogel erosion in the presence of cells remains challenging. Here we introduce the design and synthesis of efficient coumarin-based photodegradable hydrogels to overcome these limitations. A set of photolabile coumarin-functionalized polyethylene glycol linkers are synthesized through a Passerini multicomponent reaction. After mixing these linkers with thiolated hyaluronic acid, semi-synthetic photodegradable hydrogels are formed in situ via Michael addition crosslinking. The efficiency of photodegradation in these hydrogels is significantly higher than that in nitrobenzyl counterparts upon two-photon irradiation at 780 nm. A complex microfluidic network mimicking the bone microarchitecture is successfully fabricated in preformed coumarin hydrogels at high speeds of up to 300 mm s-1 and low laser dosage down to 10 mW. Further, we demonstrate fast two-photon printing of hollow microchannels inside a hydrogel to spatiotemporally direct cell migration in 3D. Collectively, these hydrogels may open new avenues for fast laser-guided tissue fabrication at high spatial resolution.