Generation of quasi-coherent cylindrical vector beams by leaky mirrorless laser.

We demonstrate that cylindrical vector beams with radial and azimuthal polarization states can be generated by leaky emission from photoexcited molecules embedded in slab-optical-waveguides which are formed on thin metal films on glass. Mirrorless lasing action in the optical waveguide leads to an order-of-magnitude collapse of the emission energy bandwidth and an emission directionality enhancement exceeding three-fold. This leads to the creation of fine rings of quasi-coherent light with radial and azimuthal polarizations. We study the effect of the leakage loss on the amplified spontaneous emission process and on the photon yield. We find a critical value of metal film thickness for the observation of mirrorless lasing action and optimal values for enhancing photon extraction.