Special issue-Optical limiting material and optical limiter
2019, 48(11): 1103001.
doi: 10.3788/IRLA201948.1103001
High-performance optical limiting (OL) is of great importance in laser protection application. Although the research of OL lasts for decades, most existing material can not possess all the desired merits such as low threshold, high linear transmittance, especially broadband and ultrafast respondence. Here, the multi-functional OL in conjugated twistacene was reported through experiments and theory. Results show that broadband OL with fast switching speed can be achieved from 480 nm-700 nm based on effective three-photon absorption. Moreover, low OL thresholds (0.15 J/cm2) and extremely high linear transmittance (92% at 532 nm) are simultaneously observed. All these combined advantages in one material shows tremendous potential in ultrafast laser protection for human eye and photonic devices.
2019, 48(11): 1103002.
doi: 10.3788/IRLA201948.1103002
As a new type of two-dimensional nanomaterial, metal carbide/nitride nanosheets (MXene) exhibits high specific surface area and electrical conductivity, and the composition, layers and thickness of that were flexibly controllable. Mxene materials have great potential applications in energy storage, catalysis, sensing and optics. The nonlinear optical effect and response mechanism of one kind of MXene material, namely Ti3C2TX nanosheets dispersion liquid were studied. It was found that the Ti3C2TX nanosheets dispersion liquid exhibited excellent optical limiting properties for nanosecond pulse laser with 532 nm and 1 064 nm wavelength, and the limiting thresholds were estimated to be 0.14 J/cm2 and 0.12 J/cm2, respectively. By measuring the dependence of nonlinear optical scattering signals on incident light power density, it was found that the optical limiting response of the material mainly originated from the nonlinear scattering effect. Compared with the traditional optical limiting material of C60, the material has the advantages of low optical limiting threshold and wide response wavelength range.
2019, 48(11): 1103003.
doi: 10.3788/IRLA201948.1103003
The Si-Pb binary composite gel glass was successfully prepared by sol-gel method using tetraethyl orthosilicate and lead acetate as precursors to introduce graphene nanosheets (GNSs) into the binary inorganic gel network. The morphology, structure, linear optics and nonlinear optical limiting properties of GNSs/Si-Pb binary composite gel glass were investigated by scanning electron microscopy, Raman spectroscopy, UV-visible absorption spectroscopy and open Z-scan technique. The results show that the GNSs can be successfully doped into the Si-Pb binary gel glass by the hydrolysis polycondensation of the precursor, and the obtained composite gel glass exhibits good uniformity and high transparency. The nonlinear optical limiting properties of GNSs have been significantly improved after incorporated into composite gel glass. Furthermore, the optical limiting properties of composite gel glass can be optimized by adjusting the concentration of GNSs in the glass. The above results provide an experimental basis and theoretical basis for expanding the materialization and deviceization of GNSs in the field of nonlinear optics.
2019, 48(11): 1103004.
doi: 10.3788/IRLA201948.1103004
Antimonene was prepared through liquid phase exfoliation of bulk materials. The as-prepared sample was characterized by scanning electron microscope (SEM), ultraviolet-visible (UV-vis) absorption spectroscopy, and Raman scattering spectroscopy in details. Broad absorption from ultraviolet to visible region was observed in the UV-vis absorption spectra. Two typical peaks assigned to Sb were detected in Raman spectra. A flat typical structure corresponding to two-dimensional materials was observed in microscopic characterization. Then Z-scan technique was utilized to test the third-order nonlinear optical properties of the sample. The as-prepared antimonene exhibited saturation absorption when excited by a laser source with pulse width of 4 ns and wavelength of 532 nm. The nonlinear absorption coefficient was -7.8610-11 m/W. Upon electron irradiation, antimonene was successfully transformed into optical limiting materials, which exhibited reverse saturable absorption with a nonlinear absorption coefficient of 8.6910-11 m/W.
2019, 48(11): 1103005.
doi: 10.3788/IRLA201948.1103005
A series of novel twistace ne-decorated arenes including heterorings (2, 5, 8) were con-veniently synthesized promoted by palladium catalyst in one step and characterized. Compared with the model twistacene 1, all of them exhibited red-shifted absorption spectra with the maximum peaks centered at 462 nm for 2, 478 nm for 5, 468 nm for 8, and emission spectra spectra with the maximum bands at 476/506 nm for 2, 497/527 nm for 5, 497/520 nm for 8 respectively, which belonged to blue and green fluorescence region. The electrochemical properties were carried out through cyclic voltammetry method and molecule 8 displayed a smallest oxidation potential at 0.35 V among them, which resulted from the oxidation of the amine moiety. Their optical limiting properties were examined via femtosecond laser. The results suggest that all of them exhibit high transmittance and 5 possesses excellent optical limiting response.
