Tuneable red,green,and blue single-mode lasing in heterogeneously coupled organic spherical microcavities

Tuneable microlasers that span the full visible spectrum,particularly red,green,and blue(RGB)colors,are of crucial importance for various optical devices.However,RGB microlasers usually operate in multimode because the mode selection strategy cannot be applied to the entire visible spectrum simultaneously,which has severely restricted their applications in on-chip optical processing and communication.Here,an approach for the generation of tuneable multicolor single-mode lasers in heterogeneously coupled microresonators composed of distinct spherical microcavities is proposed.With each microcavity serving as both a whispering-gallery-mode(WGM)resonator and a modulator for the other microcavities,a single-mode laser has been achieved.The colors of the single-mode lasers can be freely designed by changing the optical gain in coupled cavities owing to the flexibility of the organic materials.Benefiting from the excellent compatibility,distinct color-emissive microspheres can be integrated to form a heterogeneously coupled system,where tuneable RGB single-mode lasing is realized owing to the capability for optical coupling between multiple resonators.Our findings provide a comprehensive understanding of the lasing modulation that might lead to innovation in structure designs for photonic integration.

Full-color flexible laser displays based on random laser arrays

Flexible laser display is a critical component for an information output port in next-generation wearable devices.So far,the lack of appropriate display panels capable of providing sustained operation under rigorous mechanical conditions impedes the development of flexible laser displays with high reliability.Owing to the multiple scattering feedback mechanism,random lasers render high mechanical flexibility to withstand deformation,thus making them promising candidates for flexible display planes.However,the inability to obtain pixelated random laser arrays with highly ordered emissive geometries hinders the application of flexible laser displays in the wearable device.Here,for the first time,we demonstrate a mass fabrication strategy of full-color random laser arrays for flexible display panels.The feedback closed loops can be easily fulfilled in the pixels by multiple scatterings to generate durative random lasing.Due to the sustained operation of random laser,the display performance was well-maintained under mechanical deformations,and as a result,a flexible laser display panel was achieved.Our finding will provide a guidance for the development of flexible laser displays and laser illumination devices.

基于有机异质耦合微腔的双波长可切换单模激光

微纳激光器因在超灵敏化学、生物传感和光信息处理等领域具有广泛的应用前景而备受关注.由于增益饱和及空间烧孔效应造成的激光多模式会导致时序脉冲展宽和伪信号的产生,限制了激光器的应用,而单模激光可以有效解决这些问题.目前,研究者们提出的单模激光调制策略大多需要对结构进行精确加工,而能够在同一器件中实现动态可切换的多色单模激光输出仍是一个很大的挑战.本工作中,我们采用喷墨打印法制备了掺有不同增益介质的有机微腔,通过控制柔性基底的拉伸程度实现对异质耦合微腔耦合强度的控制,实现了波长可切换的双波长单模激光出射.这些结果加深了人们对异质耦合腔系统中激光调制机理的理解,并为构建可用于光学集成中的多功能小型化激光器提供了思路.

An Optically Reconfigurable Förster Resonance Energy Transfer Process for Broadband Switchable Organic Single-Mode Microlasers

Miniaturized lasers with multicolor output and high spectral purity are indispensable for various ultracompact photonic devices.Here,we propose an optically reconfigurable Förster resonance energy transfer(FRET)process to realize broadband switchable single-mode lasing based on in situ activation of acceptors.The stoichiometric ratio of the donor and acceptor in the ready-made microstructures could be modulated readily by precisely activating the acceptors through a photoisomerization process,leading to a reconstructed FRET process to achieve dynamically switchable lasing.Furthermore,dual-color switchable single-mode lasing was realized by selectively constructing the FRET process in an identical coupled microdisks system.These results advance a comprehensive understanding of excited-state dynamics in organic composite material systems,thereby providing new ideas for the rational design of miniaturized photonic materials and devices with desired performances.

Organic composite materials:Understanding and manipulating excited states toward higher light-emitting performance

Organic composite materials have been attracting extensive research interest for light-emitting applications.A wide variety of luminescent organic composite materials have been synthesized,which are of great significance for both the investigation of basic photophysics and the realization of high-performance photonic devices.Function-oriented syntheses of luminescent organic composite materials rely on the understanding and manipulating of molecular excited states.In this review,we focus on the discussion about the structure design and dynamics modulation of the electronic excited states in the organic composite materials.The excited-state structures and dynamics involve singlet/triplet levels,vibronic transition,charge transfer,and energy transfer,and so on,while the light-emitting behaviors include fluorescence,phosphorescence,persistent luminescence,electroluminescence,and lasing.We aim to give insight into the relationship between light-emitting properties and excited states of organic composite materials,which is beneficial for reaching higher tiers of design and applications of luminescent organic composite materials.