Generation of hollow beam from photonic crystal fiber with an azimuthally polarized mode

A kind of photonic crystal fiber (PCF) with an azimuthally polarized (TE01) mode is proposed to generate hollow beam (HB). The finite element method (FEM) is employed to study the polarization properties of the fiber and normalized intensity of the HB. Simulation results show that the TE01 mode with a low confinement loss in this kind of fiber can provide a high quality HB. By varying arrangement of air holes in the cladding region or changing structure parameters of the PCF, HB of different sizes can be obtained. The smallest dark spot size (DSS) and the narrowest width of HB achieved are about 1μm and 1.4μm at a wavelength of 1.55μm, respectively. This kind of PCF, which can generate HB with an azimuthally polarized mode, has great significance in the technique of optical tweezers.