Phototunable lasing of the microunit. (a) Schematic illustration of the phototunable trans-cis isomerization process of CD-1. (b) Transmission spectra of CD-doped LCs under UV (365 nm, 20 mW cm-2) illumination with 0 s, 20 s, and 60 s. (c) PL spectra of the microunit under temporal UV illumination. Insets: PL images of the corresponding microunit. Scale bar: 50 μm. (d) Plot of the lasing wavelength (637 nm and 601 nm) against the switching cycles. In each cycle, the microunit is illuminated by a UV light (365 nm, 20 mW cm-2) for 60 s and a visible light (532 nm, 20 mW cm-2) for 2 m.