Abstract
AbstractFrequency‐upconverted fluorescence and stimulated emission induced by multiphoton absorption (MPA) have attracted much interest. As compared with low‐order MPA processes, the construction of high‐order MPA processes is highly desirable and rather attractive, yet remains a formidable challenge due to its inherent low transition probability. We report the observation of the first experimental frequency‐upconverted fluorescence and stimulated emission by simultaneous six‐photon excitation in an organic molecular system. The well‐designed organic conjugated system based on cross‐shaped spiro‐fused ladder‐type oligo(p‐phenylene)s (SpL−z, z=1–3) manifests reasonably high MPA cross‐sections and brilliant luminescence emission simultaneously. The six‐photon absorption cross‐section of SpL‐3 with an extended π‐conjugation was evaluated as 8.67×10−169 cm12 s5 photon−5. Exceptionally efficient 2‐ to 6‐photon excited stimulated emission was achieved under near‐infrared laser excitation.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
