Waveguide random laser based on a disordered ZnSe-nanosheets arrangement

Abstract

A waveguide scheme is constructed by coating the matrix of randomly distributed ZnSe nanosheet structures with a layer of dye-doped polymer, which provides strong feedback or gain channels for the emission from the dye molecules and enables successful running of a random laser with FWHM of ~0.65 nm. The strong scattering by the nanostructures and the strong confinement provided by the active waveguide layer are the key essentials for the narrow-band and low-threshold operation of this random laser. The random laser scheme reveals an obvious two-threshold behavior, which is corresponding to the thresholds of TM and TE modes. The feedback mechanisms for laser action are investigated by power Fourier transforming of the spectra. This kind of active waveguide not only provides high quality confinement of the radiation for efficient amplification, but also enables possible directional output of this kind of random laser.

Directional and Polarized Lasing Action on Pb‐free FASnI3 Integrated in Flexible Optical Waveguides

“…For example, theoretical studies predict that this factor is limited to β = 0.1 in a generic random laser [51] or β = 0.04 in a random laser based on MIE resonances. [52] Similar values have been obtained experimentally in a suspension of TiO 2 nanoparticles inside a dye solution, β = 0.07, [53] in a Nd:LuVO4 crystal powder, β = 0.18, [54] and MAPbBr 3 perovskite film deposited on PET, β = 0.14. [55] These low values of β are usually correlated with high RL thresholds (≈mJ cm −2 ).…”

“…Again, it is worth mentioning that the directionality provided by the WG represents a cheap and elegant way to increase the signal-to-noise ratio and provide a direct outcoupling of laser light from the WG without expensive technology or complicated pump systems. [52][53][54][55][56][57] Moreover, the outcoupled RL light from the WG is polarized parallel to the TE polarization, which is observed for the first time in perovskite thin films, to the best of our knowledge, but previously observed in ZnO thin films, [58] in liquid crystals [59] or plasmonic systems. [60]…”

All-optical guided-wave random laser in nematic liquid crystals

“…In this work we control the RL emission of a planar dye-doped NLC sample exploiting all-optical reorientation to launch a soliton at a wavelength well removed from the guest-host absorption resonance. We demonstrate that, in analogy to other guiding geometries [37], the light-induced waveguide associated to a soliton can confine the emitted photons in the extraordinary polarization [33,38], enhancing the overall lasing efficiency. This approach to random lasing, combining a resonant light-matter interaction between the pump and the guest-host with a non-resonant one supporting beam self-confinement via reorientation, can be exploited for a novel generation of controllable cavity-less lasers.…”

Optical fiber facet-based random lasers

“…从刚性拓展到柔性 [38][39][40] . 泵浦方式涉及光泵浦和电泵 浦 [40][41][42][43][44][45][46] , 其中光泵浦随机激光器被广泛用于研究或揭 示随机激光产生过程中的基本物理效应或物理机制, 激发形式从单光子激发拓展到多光子激发 [47][48][49][50] ; 增益 介质涉及小分子染料 [51,52] 、半导体材料 [5,53,54] 、发光 聚合物 [55][56][57] 、量子点 [21,[58][59][60] 、钙钛矿材料 [61][62][63][64][65] 和上转 换材料等 [66][67][68][69] ; 散射结构从电介质扩展到金属纳米颗 粒 [70][71][72][73][74][75][76] , 还涉及液晶 [77][78][79][80][81] 和生物组织等 [24,[82][83][84]…”