Advances in Energy‐Level Systems of Organic Lasers

Abstract

Organic gain materials, with the merit of abundant excited-state processes with large stimulated emission cross-section, show considerable potential in lasers. The abundant excited-state processes provide excellent platform for the construction of various forms of energy-level systems, based on which the efficient population inversion and the tailorable gain region are supported. Herein, the development of organic lasers with distinctive energy-level systems is summarized according to the classification of excited-state gain processes including singlet quasi-four-level transition, energy transfer, excimer, charge transfer (CT), excited-state intramolecular proton transfer (ESIPT), and some other novel photophysical processes, giving deep insight into the inherent relationship between energy-level systems and laser action. Finally, the challenges and perspectives for the future development are presented, hopefully to offer valuable enlightenment for the further optimization of energy-level systems toward high-gain organic lasers including electrically pumped organic lasers.

Construction of organic micro/nanocrystal lasers: from molecules to devices

“…21 Among various materials, organic molecules have abundant excited-state processes, including lots of different excited states, which can provide various inherent forms of energy level systems and are conducive to the population inversion of stimulated emission. 11,52 Many organic molecular materials have been proven to be suitable optical gain media, as shown in Fig. 2a.…”

Fluorescence and Phosphorescence Energy Transfer in Cucurbituril‐Based Supramolecular Systems

“…However, cyclodextrin is not the only secondary host used in the CB[n]-based systems with phosphorescence energy transfer. Thus, amphiphilic sulfonatocalix [4]arenes (SC4AX, where X stays for the chain length indication, cf. Figure 7) modified with alkyl chains of different lengths at their lower rim were applied as a second macrocyclic component in 5 out of 14 assemblies (Table 1).…”

“…Förster resonance energy transfer (FRET) is one of the fundamental mechanisms in the Nature enabling conversion of the solar energy into the energy of chemical bonds in living beings via photosynthesis. [1] In artificial systems, FRET is broadly applied in optical sensors, [2,3] lasers, [4] solar cells, [5] organic photonics and photovoltaics, [6,7] solar energy storage systems, [8] super-resolution fluorescent microscopy [9] as well as in biomedical studies. [10][11][12][13] The physical principle of FRET was established by T. Förster in 1948.…”

Dual-Color Lasers in Interlayer-Free Solution Processed Polymeric Bilayer Devices

“…For a given gain medium, a change in the emission band can be achieved by tailoring the energy gap between the excited state where population inversion happens and the ground state. 5 For instance, in the well-studied PFO film, by controlling the formation of the βphase, optical gains in the self-doping Forster resonant energy transfer system were shown at wavelength 453 nm from the glassy phase and at wavelength 468 nm from the β-phase simultaneously. 6 In some novel materials, approaches of developing variable wavelength lasing were achieved by utilizing the excited-state intramolecular proton transfer (ESIPT) process.…”

“…In recent years, multiwavelength organic lasers have attracted intense attention for their potentials in full-color laser display, highly sensitive sensing, encryption optical communication, etc. For a given gain medium, a change in the emission band can be achieved by tailoring the energy gap between the excited state where population inversion happens and the ground state . For instance, in the well-studied PFO film, by controlling the formation of the β-phase, optical gains in the self-doping Förster resonant energy transfer system were shown at wavelength 453 nm from the glassy phase and at wavelength 468 nm from the β-phase simultaneously .…”