All-Optical\nControl of Vortex Lasing in Silicon–Organic\nLattices

This paper reports a silicon–organic hybrid lattice\nthat\ncan lase with vortex emission and allow all-optical control. We combine\nan array of amorphous silicon nanodisks with gain from dye molecules\nin organic solvents to generate vortex lasing from bound states in\nthe continuum under pulsed optical pumping. Irradiating the device\nwith an additional continuous wave green laser beam can cause optical\nheating in silicon and lead to negative change in the refractive index\nof the organic solvents; meanwhile, the green laser beam can provide\nadditional gain. Dynamic tuning of the lasing wavelength is achieved\nby varying the intensity of the controlling beam. Furthermore, the\nvortex beam lasing can be switched to single-lobed beam lasing by\nmoving the controlling spot to break the in-plane symmetry within\nthe pumping spot. Our findings could shed new light on active silicon\ntopological devices.