Single-particle to single-particle transformation of an active type organic μ-tubular homo-structure photonic resonator into a passive type hetero-structure resonator

Self-assembled hexagonal organic submicrotubes, upon electronic excitation with an UV laser, display an active type polarized whispering gallery mode (WGM) resonance in the visible (Vis) range (400–600 nm). Due to the photonic cavity effect the tubes show fluorescence (FL) signal intensity 5× greater than the corresponding powder state. Furthermore, the same tubes, which are passive to a visible laser, produce yellow-orange emitting carbonaceous lumps when burnt with an intense laser beam (42 mW) forming a chemically binary heterogeneous structure. The hetero-structure upon excitation with a visible laser at the passive tubular part showed emission in the Vis-Near infrared (NIR) range (500–800 nm) with WGMs thus producing a passive/active type hetero-structure photonic resonator.