Supplementary document for Two-dimensional guided-mode resonance gratings with an etch-stop layer and high tolerance to fabrication errors - 5855838.pdf

Supplement

Supplementary document for Grayscale-patterned integrated multilayer-metal-dielectric microcavities for on-chip multi/hyperspectral imaging in the extended visible bandwidth - 6253787.pdf

Supplemental document

Ionic Solvent-Assisted MAPbBr₃ Perovskite Film for Two-Photon Pumped Single-Mode Laser

Miniaturized coherent light sources on the nanoscale are highly desired for on-chip photonics integration. However, when approaching the diffraction limit, the sub-wavelength-scale all-dielectric lasers are difficult to realize due to the trade-off between lasing performance and physical size. Especially for a thin-film laser, usually an externally complex cavity is required to provide the necessary optical feedback. Herein, we successfully shrink the MAPbBr3 perovskite thin-film laser to sub-wavelength scale (300 nm) with simplified cavity design using only an ultraviolet glue layer and a quartz glass. The morphology quality and the gain properties of the film are enhanced by introducing ionic liquid. Consequently, the stable and low-threshold single-mode laser with a highly linear polarization degree of 78.6% and a narrow line width of 0.35 nm is achieved under two-photon excitation. The excellent single-mode laser with sub-wavelength scale and ultrasimplified structure could provide a facile and versatile platform for future integrated optoelectronic devices

Supplementary document for Design of arbitrary energy distribution beam splitters base on metagratings with multilayer by a hybrid evolutionary particle swarm algorithm - 6685021.pdf

revised versio

Supplementary document for Broadband depolarized perfect Littrow diffraction with multilayer freeform metagratings - 6380604.pdf

Supplementary Figures and Note

Thermally Evaporated MAPbBr₃ Perovskite Random Laser with Improved Speckle-Free Laser Imaging

Metal halide perovskites (MHPs) are very promising materials for lasing applications due to their remarkable optical gain properties. Currently, most perovskite-based lasers are fabricated using lab-scale solution processing methods. The thermal evaporation (TE) method could be a promising alternative technology for scale-up fabrication with significantly improved reproducibility. Unfortunately, the fast and uncontrollable crystal growth process in thermal evaporation leads to defective films, and hence their laser performance usually falls behind their solution-processed counterparts. Here, we demonstrate high-performance random lasers and explore their speckle-free imaging application from perovskite thin films fabricated by an improved tri-source thermal co-evaporation approach assisted by a multifunctional Lewis base additive, triphenylphosphine oxide (TPPO). The optical gain of TPPO-passivated MAPbBr3 perovskite films is as high as ∼5 times that of the pristine one, and the corresponding gain lifetime is almost doubled after TPPO passivation. Due to the small grain size and compact confinement-induced strong multiple scattering, a random laser with threshold reduced by half and a high polarization degree of 78.4% is realized in thermally evaporated MAPbBr3:TPPO perovskite films. These findings would provide a possible route to scale up the manufacturing of high-performance perovskite materials and devices and open new perspectives for integrated speckle-free laser imaging systems

Random Lasing from Thermally Evaporated Quasi-Two-Dimensional Perovskite Film for Speckle-free Imaging

Quasi-two-dimensional (quasi-2D) perovskites are promising as a gain medium for laser applications owing to their inherent multiple quantum wells and remarkable stability. Meanwhile, thermal evaporation deposition is a promising complementary approach to further advance the commercialization of perovskite-based lasers. However, investigations into thermally evaporated perovskite lasers are scarce, and their performance is significantly inferior to that of their solution-processed counterparts. Herein, we demonstrate a high-quality thermally evaporated quasi-2D perovskite film with excellent gain properties via a tri-source co-evaporation strategy. The carrier dynamics and gain nature of the perovskite film are revealed with a long gain lifetime of 66.5 ps. The net modal gain is up to 1071 cm–1, which is afforded by rapid carrier accumulation (<0.25 ps) and facile buildup of population inversion. As a result, random lasing from the quasi-2D perovskite film with a low threshold of 10.39 μJ/cm2 is achieved. Furthermore, under the illumination of random lasing, clear speckle-free imaging with an impressively low speckle contrast of C ∼ 0 is demonstrated. This work highlights the possibility of using thermally evaporated perovskites for the development of high-performance random lasers and integrated speckle-free imaging systems

Gate-Tuning Hybrid Polaritons in Twisted α‑MoO₃/Graphene Heterostructures

Modulating anisotropic phonon polaritons (PhPs) can open new avenues in infrared nanophotonics. Promising PhP dispersion engineering through polariton hybridization has been demonstrated by coupling gated graphene to single-layer α-MoO3. However, the mechanism underlying the gate-dependent modulation of hybridization has remained elusive. Here, using IR nanospectroscopic imaging, we demonstrate active modulation of the optical response function, quantified in measurements of gate dependence of wavelength, amplitude, and dissipation rate of the hybrid plasmon–phonon polaritons (HPPPs) in both single-layer and twisted bilayer α-MoO3/graphene heterostructures. Intriguingly, while graphene doping leads to a monotonic increase in HPPP wavelength, amplitude and dissipation rate show transition from an initially anticorrelated decrease to a correlated increase. We attribute this behavior to the intricate interplay of gate-dependent components of the HPPP complex momentum. Our results provide the foundation for active polariton control of integrated α-MoO3 nanophotonics devices