On the basis of the Li vacancy model of intrinsic defects in LiNb03 crystal, the defect structure formed in LiNbO3:Mg varying with the Mg content are proposed. The Liz0 and NbzOs contents, the Li/Nb ratio in the crystal, and the density of the crystal are calculated by using the defect structure. The calculated values are in good agreement with the reported experimental results.

A method to determine the focal length of a thermal lens and pumping laser beam waist in the gain medium in laser-diode-pumped solid-state lasers is presented. This method, using resonator transform circle theory, is both simple and reliable. The measured focal length of the thermal lens is used to calculate the beam waist of pumping laser inside the gain medium. The effect of the thermal lens on the output power is also measured and analyzed.

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Articles you may be interested inIntense 1.54 μ m fluorescence of Er 3 + / Yb 3 + codoped phosphate glass and the three-photon phenomenon of near infrared upconversion luminescence 4.25 dB gain in a hybrid silicate/phosphate glasses optical amplifier made by wafer bonding and ion-exchange techniques Appl. Phys. Lett. 85, 5176 (2004); 10.1063/1.1829141 Infrared and visible luminescence properties of Er 3+ and Yb 3+ ions codoped Ca 3 Al 2 Ge 3 O 12 glass under 978 nm diode laser excitation

This work aims to develop a novel multimode (photothermal/colorimetric/fluorescent) nanozyme-linked immunosorbent assay (NLISA) based on the in situ generation of Prussian blue nanoparticles (PBNPs) on the surface of magnetic nanoparticles (MNPs). Being considered the most toxic among the mycotoxins, aflatoxin B1 (AFB1) was chosen as the proof-of-concept target. In this strategy, MNPs, on which an AFB1 aptamer was previously assembled via streptavidin-biotin linkage, are anchored to 96-well plates by AFB1 and antibody. In the presence of HCl and K4Fe­(CN)6, PBNPs formed in situ on the MNP surface, thereby achieving photothermal and colorimetric signal readout due to their photothermal effect and intrinsic peroxidase-like activity. Based on fluorescence quenching by MNPs, Cy5 fluorescence was recovered by the in situ generation of PBNPs to facilitate ultrasensitive fluorescence detection. Photothermal and colorimetric signals allow portable/visual point-of-care testing, and fluorescent signals enable accurate determination with a detection limit of 0.54 fg/mL, which is 6333 and 28 times lower than those of photothermal and colorimetric analyses, respectively. We expect that this proposed multimode NLISA can not only reduce the false-positive/negative rates through the multisignal crossdetection in AFB1 monitoring but also provide a universal way of sophisticated instrumentation-free, easy-to-use, cost-effective, and highly sensitive detection of other food hazards.