Fig. 1. WGM lasing of chalcogenide materials with different resonant cavity structures. (a)(b) Schematic WGM modes and excitation spectra of MAPbI_xCl_3-x chalcogenide nanosheets^[30]; (c) lasing characteristics of MAPbBr₃ microcubes synthesized by solution method^[31]; (d)(e) lasing characteristics of single-crystalline CsPbX₃ nanosheets synthesized by gas-phase method^[32]; (f) lasing of CsPbBr₃ microcubes cavities synthesized by gas-phase method^[33]; (g)(h) lasing of gas-phase synthesized RbPbBr₃ microcube excitation properties and polarization spectra^[34]; (i) high-temperature upconversion CsPbBr₃ microcube lasing^[35]

Fig. 2. Resonant cavity lasing and laser display of chalcogenide microspheres. (a)(b) Schematic WGM laser mode and excitation spectra of CsPbX₃ microspheres synthesized by gas-phase method^[36]; (c)(d) schematic two-photon-pumped CsPbBr₃ microspheres and laser characteristics^[37]; (e) laser characteristics of RbPbBr₃ microspheres synthesized by gas-phase method^[38]; (f) fs-processed CsPbX₃ thin films used for laser display^[40]; (g)(h) twin-sphere CsPbBr₃ microsphere coupled excitation properties and polarization spectra^[39]

Fig. 3. Chalcogenide nanowire FP mode wavelength tunable lasing. (a)‒(c) Tuning of halogen ions in MAPbX₃ nanowires to achieve lasing out in the 500 nm to 770 nm band^[43]; (d)(e) tuning of halogen ions at the X position in CsPbX₃ micro-nanowires to achieve lasing in the 430 nm to 730 nm band^[44]; (f)(g) achieving lasing out in a single CsPbCl_3-3xBr_3x nanowire from 480 nm to 525 nm continuously tunable nanowire lasing^[45]

Fig. 4. WGM mode wavelength tunable laser for chalcogenide materials. (a) Adjusting the halogen ions in the CsPbX₃ microsphere cavity to realize the visible to infrared wavelength laser emission^[36]; (b) adjusting the ratio of Rb/Cs in the cavity indication of the Rb_xCs_1-xPbBr₃ microcubic block to realize the 470 nm to 535 nm wavelength laser^[34]; (c) adjusting the ratio of Rb/Cs to realize the emission wavelength tuning for the Rb_xCs_1-xPbBr₃ microsphere cavity^[38]; (d)(e) adjusting the edge length of CsPbBr₃ microcubes to realize their emission wavelength tuning, and the emission wavelength is linearly related to the edge length^[35]; (f)(g) diameter of CsPbBr₃ and RbPbBr₃ microspheres to tune their excitation wavelengths^[36,38]

Fig. 5. Optical PUFs based on FP microcavities. (a) Asymmetric liquid rupture results in random capillary bridge size^[52]; (b) size distributions of four emission modes conforming to the Gaussian distribution are established by extracting the laser emission and cavity length for nanolasers with random size^[52]; (c) nanowire array is grown randomly oriented by a one-step recrystallization method, and when the pumped laser is focused on the nanowire, the encryption key is obtained based on its laser output^[53]; (d) based on the number of laser modes of the nanowire array, the quaternary and binary keys are obtained respectively^[53]

Fig. 6. Optical PUFs based on WGM microcavities. (a) Fluorescence micrograph of microform for microhemisphere array and corresponding emission spectrum^[54]; (b) post-processing diagram of deformed microcavity array^[55]; (c) randomly deformed microcavity array realizes different quaternary and binary encoding keys by varying power and obtains encryption keys with high encoding capacity by combining them^[55]

Fig. 7.

Ultrafast encoder based on micro-nano structure. (a) Ultrafast responses in parallel and vertical linear polarization directions^[62]; (b) THz polarization code 1110 based on perovskite microsphere luminescence^[62]; (c) single- and double-layer coded pulse shapes^[62]; (d) THz double-layer encoding with code sequence 2120^[62]; (e) carrier dynamics for high/low speed coding^[63]; (f) relationship between energy consumption efficiency of different coding methods and encoding frequency^[63]

Fig. 8. Single-mode lasing properties of CQDs. (a) Illustration of a single CsPb(Br_0.5I_0.5)₃ CQDs/ZnO composite microcavity pumped by a 400 nm femto-second laser on a silicon substrate^[83]; (b) excitation power-dependent lasing from composite microcavity^[83]; (c) true-color photographs of QD ring laser at different excitation power^[82]; (d) four representative spectra in a ring laser^[82]; (e) power-dependent emission spectra of a typical CQDAM at 450 K^[86]; (f) photoluminescence (PL) intensities at the cavity resonance energy and the nonresonant energy varies with excitation density^[86]

Fig. 9. Laser performance of self-assembled superlattice microcavities. (a) Resonance optical modes of QDSM with different sizes^[89]; (b) power dependence of PL intensity in cavity mode^[89]; (c) pumping-density-dependent PL spectra from an individual QD superlattice microcavity at 10 K^[91]; (d) power-dependent emission spectra from the CsPbBr₃ QDs superlattice^[90]; (e) PL intensity and spectral FWHM in CsPbBr₂Cl QD superlattices as a function of pumping density^[92]; (f) multi-wavelength tunable lasing of typical sites on alloy superlattice^[93]

Fig. 10. Optical properties of superfluorescence. (a) Spectral and energy maps of CsPbBr₃ NCs and superlattices^[94]; (b) schematic of the formation of superfluorescence in the superlattice^[102]; (c) time-resolved PL decay curves of uncoupled and coupled quantum dots^[102]

Fig. 11. Ultrafast optical properties of cavity-enhanced superfluorescence. (a) Schematic diagram of cooperative (thermal) dipole systems in CESF and conventional laser optical cavities^[89]; (b) time-dynamical fluorescence spectra of different structures^[89]; (c) stripe camera images and fitted TRPL decay curves at pumping densities of 0.7 P_th, 1.1 P_th, and 2.3 P_th^[91]

Fig. 12. Quantum dot superlattices promote exciton delocalization and act as terahertz quantum switches. (a) Molecular dynamics simulation of nanocrystal binding in toluene and hexane^[109]; (b) schematic of theoretical simulations of anion exchange processes in the superlattice^[92]; (c) effect of ligands on the self-assembly interactions of quantum dots^[90]; (d) schematic diagram of CsPbBr₂Cl superlattices mitigating photoinduced phase segregation by attenuating exciton-phonon coupling compared to uncoupled quantum dots^[93]; (e) performance of THz quantum conversion devices based on superlattice microcavities^[89]

Fig. 13. Superfluorescence kinetics and room-temperature superfluorescence mechanism of cooperating excitons under controlled perturbation. (a) Time-resolved photoluminescence spectra of a perturbation introduced at different moments at 10 K^[116]; (b) explanation of the physical mechanism of echo-like radiation^[117]; (c) schematic diagram of a classical vibration isolation system^[118]