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Flexible organic photonic devices for high-performance optical information processing can be produced via ink-jet printing.

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Wavelength tunable micro/nanolasers are indispensable components for various photonic devices. Here, we report broadband tunable microlasers built by incorporating a highly polarized organic intramolecular charge-transfer (ICT) compound with a supramolecular host. The spatial confinement of the ICT dye generates an optimized energy level system that favors controlled population distribution between the locally excited (LE) state and the twisted intramolecular charge-transfer (TICT) state, which is beneficial for significantly broadening the tailorable gain region. As a result, we realized a wide tuning of lasing wavelength in the organic supramolecular microcrystals based on temperature-controlled population transfer from the LE to TICT state. The results will provide a useful enlightenment for the rational design of miniaturized lasers with desired performances.

Flexible microdisk whispering-gallery-mode (WGM) resonators with high quality factors were achieved through the controlled assembly of organic materials with an emulsion-solvent-evaporation method. The high material compatibility of the assembled microdisks enabled us to realize low-threshold WGM lasers by doping with organic dyes as gain media. Furthermore, the emulsion-assisted self-assembly provided a strategy for the one-step fabrication of microwire-waveguide-connected microdisk heterostructures, which can be utilized for the efficient output of the isotropic WGM lasers from the coupled waveguides. We hope that these results will pave an avenue for the construction of new types of flexible WGM-based components for photonic integration.

and facilitates the population transfer from the LE to the ICT state. This is helpful in building an effective laser level system comprising two gain states. The ICT dye@MOF microlasers became controllable through the introduction of guest solvents with different polarities, which was subsequently utilized to build stable and wide-wavelength-tunable microlasers. The results offer a comprehensive understanding for the construction of stable and tunable lasers in confined systems, and provide guidance for the development of miniaturized lasers with higher performance.Cyanine dyes, a typical type of ICT compounds, exhibit wide spectrum emission for their unique excited states, which are very suitable for the flexible tuning of the gain region (Scheme 1). However, in strong polar organic solvents, the ICT dyes perform a rapid transformation from planar LE to TICT state. [6] which is a "dark state" undergoing a nonradiative decay to the ground state. [7] This is a main gain loss channel that results in a high lasing threshold; therefore, an effective strategy to reduce this loss must be applied by restricting the rotation of the dye molecules to get lasers with lower threshold and higher tunability. Confined system can effectively reduce the above energy loss, helping to materialize a low threshold lasing by the facile population inversion. [8] As a kind of porous host materials, the pore confinement of MOFs can not only minimize the ACQ of organic dyes, but also effectively reduce the nonradiative decay from the TICT state, which is beneficial for enhancing the emission process from the LE and ICT states, and achieving HLCT (hybridized local and charge-transfer) lasers. [9] The ICT dye@MOF microlasers would be tunable through the polarity regulated emission processes, which can thus be utilized to build stable and wide-wavelength-tunable microlasers.In this work, mesoporous bio-MOF-100 [10] (Zn 8 (ad) 4 -(BPDC) 6 O 2 ·4Me 2 NH 2 , ad = adeninate; BPDC = biphenyldicarboxylate) with anion microenvironment ( Figure S1, Supporting Information) was selected as the host matrix. This structure consists of discrete zinc-adeninate octahedral building units (ZABUs) interconnected with BPDC linkers. Twelve BPDC linkers connect each ZABU to four neighboring ZABUs, and this connectivity is periodically repeated throughout the extended three-dimension frameworks, generating large pores measuring ≈28 Å in diameter ( Figure S2, Supporting Information). This dimension is very suitable for encapsulating the nanosized cyanine dyes. [5] Especially, the cyanine dyes holding positive charges are preferred for their charge matching with bio-MOF-100. Hemicyanine dye DASPI (4-p-(dimethylamino) styryl)-1-methylpyridinium, about 6.3 Å in width and 14.3 Å in length) was chosen as the guest gain material. The internal pores of bio-MOF-100 contain a large number of Me 2 NH 2 + cations, which allows the introduction of the cationic DASP + dyes Wavelength-tunable microlasers have attracted extensive attention for their important roles in on-chip...

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An improved lipid extraction process has been established for microalgal using enzyme-assisted aqueous extraction processing (EAEP), which mainly involved in sonication and enzyme treatment. As compared to cellulase, neutral protease and alkaline protease, significantly higher lipid recovery was achieved by snailase and trypsin. The highest lipid recovery of 49.82% was obtained by a combined sonication-enzyme treatment at pH 4. The enhancement mechanism of the EAEP was analyzed in terms of the particle size of cream and zeta potential. In addition, microalgal lipid recovery was also affected by lipid class composition and the type of algae. The present study demonstrates a promising alternative to conventional lipid extraction of microalgae and the quantitative information on EAEP of oleaginous alga can provide valuable data for process design at pilot and industrial scale.