Coherent light signals generated at the nanoscale are crucial to the realization of photonic integrated circuits. Self-assembled nanowires from organic dyes can provide both a gain medium and an effective resonant cavity, which have been utilized for fulfilling miniaturized lasers. Excited-state intramolecular proton transfer (ESIPT), a classical molecular photoisomerization process, can be used to build a typical four-level system, which is more favorable for population inversion. Low-power driven lasing in proton-transfer molecular nanowires with an optimized ESIPT energy-level process has been achieved. With high gain and low loss from the ESIPT, the wires can be applied as effective FP-type resonators, which generated single-mode lasing with a very low threshold. The lasing wavelength can be reversibly switched based on a conformation conversion of the excited keto form in the ESIPT process.
Low-threshold single-mode lasing was achieved via excited-state intramolecular proton transfer (ESIPT)-assisted population inversion in crystal organic nanowires fabricated by the self-assembly of proton-transfer dye molecules. The lasing wavelength can be reversibly switched based on the photoinduced conformation conversion of the excited keto form in the ESIPT process.