Ultrashort laser pulse doubling by metal-halide perovskite multiple quantum wells

Abstract

Multiple ultrashort laser pulses are widely used in optical spectroscopy, optoelectronic manipulation, optical imaging and optical signal processing etc. The laser pulse multiplication, so far, is solely realized by using the optical setups or devices to modify the output laser pulse from the optical gain medium. The employment of these external techniques is because the gain medium itself is incapable of modifying or multiplying the generated laser pulse. Herein, with single femtosecond laser pulse excitation, we achieve the double-pulsed stimulated emission with pulse duration of around 40 ps and pulse interval of around 70 ps from metalhalide perovskite multiple quantum wells. These unique stimulated emissions originate from one fast vertical and the other slow lateral high-efficiency carrier funneling from lowdimensional to high-dimensional quantum wells. Furthermore, such gain medium surprisingly possesses nearly Auger-free stimulated emission. These insights enable us a fresh approach to multiple the ultrashort laser pulse by gain medium.

Geometry-Programmable Perovskite Microlaser Patterns for Two-Dimensional Optical Encryption

“…In comparison with broadband fluorescence or phosphoresce emission, lasing emission signals with narrow line width have been recognized as novel cryptographic primitives for security applications regarding its easily distinguishable readout. ,, At the same time, lasing action is a self-modulation process in an optical resonator, − which offers us a great opportunity to achieve tunable laser output by cavity geometry design instead of external stimuli, holding great potential for robust and high security-level data recording and protection. Compared with traditional inorganic semiconductors, metal lead halide perovskites, that is, MAPbX 3 (MA = methylammonium and X = Cl, Br, I), are emerging as an important class of lasing materials − due to their outstanding optical gain and remarkable solution processability, which enable us to tailor the geometry of perovskite microstructures and further laser output in a controllable way, thus demonstrating great confidential encryption abilities. − To this end, processing of perovskite materials into large-scale arrays with regular-shaped elements is highly demanded for the creation of 2D lasing patterns. Until now, many well-defined perovskite microstructure arrays have been prepared with variable geometries, − which enable them to serve as high-quality resonators for lasing emissions.…”

Cascade Electron Transfer Induces Slow Hot Carrier Relaxation in CsPbBr3 Asymmetric Quantum Wells

“…Lead halide perovskite (LHP) semiconductors have emerged as potential materials for future-generation optoelectronics, − such as photovoltaics, , photocatalysis, X-ray scintillation, , and detection devices . The performance of these devices can be further improved by harvesting the excess energy of the hot carriers before these carriers are converted into heat during the cooling process .…”

Defect Behaviors in Perovskite Light-Emitting Diodes

“…Lead halide perovskites have garnered significant research interest within the past decade. , Since the organic–inorganic hybrid perovskite was first applied to solar cells, interest in its optoelectronic properties has gradually extended to other research areas such as photovoltaics, − light-emitting diodes (LEDs), , lasers, , and photodetectors. , Perovskite is generally considered to be a “defect tolerant” material, but extensive research has shown that the enhancement in the performance of materials and devices is inseparable from the regulation of defects. − …”