Low Loss Dielectric Metasurface Optically Pumped Organic Laser for Manipulation of SAM-OAM of Light

The manipulation of SAM (spin angular momentum) and OAM (orbital angular momentum) of light in laser sources has been one of the desired techniques in optics community. This is because the SAM-OAM mode of light provides important freedoms for information encoding, classical and quantum optical communications, imaging and frequency conversion. The manipulation of SAM-OAM mode of light in macroscopic laser system can be achieved by using conventional optics. However, the conventional optics cannot meet the dimensional requirement of on-chip integration, which will finally limit the miniaturization of functional laser sources. The rapid development of photonic metasurface, a class of structured interfaces with spatially variant nanostructures, could provide a novel solution.

This project aims at generating spin controlled OAM of laser by integrating ultra-thin dielectric meta-surface, a new class of structured interface consisting of spatially varying photonic nanostructures with sub-wavelength feature size, into optically pumped organic laser. There are two advantages using dielectric metasurface; optical spin controlled dielectric meta- surface acts as a circular polarization beam splitter, which can efficiently project the circularly polarized and unpolarized lasing emission to the first diffraction and 0th orders simultaneously. In addition, the dielectric metasurface, fabricated on quartz substrate, enables on-chip control of SAM-OAM simultaneously on an ultra-compact laser device. In this proposed project, first the dielectric metasurfaces will be designed such that the functionalities of circular polarization manipulation will be optimized at visible wavelengths of the optically pumped organic semiconductor laser; we have accumulated several years of fabricating optically pumped organic laser and its overall physical dimension can be very compact as well as greater flexibility in its design. Then, the dielectric metasurface will be integrated into DFB and F-P cavity organic laser to demonstrate ultra-compact on-chip vortex generation. The successful implementation of this project will open new avenues for on-chip wavefront engineering of lasing process from optically pimped thin film organic laser.