MOF‐Based Organic Microlasers

Abstract

on. [8][9][10][11][12][13] However, most of these systems do not provide gain medium with high load concentrations (usually 0.005-0.05 m), [14,15] making it difficult to obtain low threshold laser outputs and limiting the laser output power, which is even more disadvantageous for multiphoton absorption (MPA) upconverting laser output. To take advantage of the spatial confinement of host materials, zeolites, nanoporous silica, and the like have been explored to incorporate dye mole cules and semiconducting polymers into the corresponding crystals and thin films to develop solid state lasing. [16,17] But possibly due to the natural chemical incompatibility of the inorganic host and the organic guest, the loading concentra tion of the gain medium is even lower (0.005-0.0005 m), or uneven distribution of the gain medium and poor solid morphology may occur.In recent years, a new type of ordered porous crystalline material, metalorganic frameworks (MOFs) has been devel oped as a powerful platform for functional molecules, [18][19][20][21] and its highly designable framework and pore/channel structure (including morphology and size, physical and chemical proper ties) can provide excellent spatial confinement effect for organic laser gain molecules. Such spatial confinement effect permits high concentration (>0.1 m) of gain material with minimized quenching effect. In addition, MOFs have some other advan tages. For example, first, MOFs are very easy to obtain single crystal morphology and certain morphology symmetries can be naturally and efficiently utilized as the laser resonant cavities without adding any other optical elements, which is very con ducive to achieving high quality microlasers. Second, the highly designable ordered framework and pore structure of MOFs can impart spatial (orientation, position, etc.) regulation and phys icochemical properties regulation of these laser functional mole cules, thereby enabling unique laser performance expression. Third, combining the pores/channels of MOFs, unsaturated metal sites, and functional sites of organic ligands for the enrich ment and recognition of different substances can lead to many novel and attractive applications, such as high sensitivity and/ or high selectivity laser sensing/detection and so on (Figure 1).In this review, we discuss the fundamental knowledge of lasing behavior from MOFs and their hybrid materials, and then summarize the latest advances in MOFbased organic micro lasers, highlighting the performance improvements and new features introduced by MOF systems. We discuss in detail the construction strategy and unique laser characteristics of existing MOFbased organic microlasers. Finally, we provide conclusions and prospects for future research directions in this field.Organic lasers have become an important research and application target for the development of optoelectronics and future photonics due to their ease of preparation and miniaturization, low threshold, and wideband tunability, as well as large optical and nonlinear optical cross sect...

Topological‐Distortion‐Driven Amorphous Spherical Metal‐Organic Frameworks for High‐Quality Single‐Mode Microlasers

“…Up to now, various MOFs microstructures, including 1D microwires, 2D miroplates and 3D polyhedral structures, have been developed to serve as appealing Fabry‐Pérot (FP) or whispering‐gallery‐mode (WGM) lasing resonators [6] . However, these microresonators generally have rigid multiple edge boundaries resulting from the anisotropy nature inherent in crystal growth [7] . The non‐smooth edge boundaries between different crystal planes result in strong scattering losses, and hinder further development of MOFs‐based microlasers [8] …”

Controlled Shape Evolution of Pure‐MOF 1D Microcrystals towards Efficient Waveguide and Laser Applications

“…The derived parameter n around 490 nm is ≈2.85, which is high enough to ensure effective optical confinement in nanowires. These MOF nanowries exhibited the quality factors ( Q ) of ≈10 3 (Figure S7), pretty high for MOF‐based microcavities [10a] …”

Controllable broadband multicolour single-mode polarized laser in a dye-assembled homoepitaxial MOF microcrystal

“…Its highly engineered pore/channel structure provides excellent spatial confinement to assemble and isolate guest organic molecules, which can reduce intermolecular interactions for effective inhibition of excited-state energy transfer and even control of output emission characteristics 26 – 28 . In addition, the smooth and regular crystal morphology of the MOF can enable it to effectively act as an optical resonator to provide optical feedback 29 . If guest organic molecules with different gain bands can be spatially separated by MOF crystal and pore/channel engineering while maintaining the efficient spatial confinement and orientation of the host MOF for the guest organic molecules, that is, ensuring an extremely high-gain concentration and oriented emission transition moment, then realization of a multicolour single-mode polarized laser with a low threshold in the shortened resonant cavity is expected.…”