ABSTRACT
A broadband TE(01) mode fiber coupler based on dual-core photonic crystal fiber (PCF) is proposed by introducing gold nanowires and fluorine-doped (F-doped) layers in the core areas. With an appropriate choice of the parameters of the F-doped layers and air hole space, the wavelength bandwidth can be increased to beyond 500 nm with the coupler length below 0.1 m for the 3 dB fiber coupler.
ABSTRACT
A fiber with a thin-metallic layer introduced between the central core and the cladding is proposed to lift the near-degeneracy of the modes TE01, TM01, and HE21. It can be used to obtain the pure mode TE01 as both the active and passive fibers. In the case of the active fiber, the fiber with the appropriate rare earth doping profile in the central core is presented as the gain medium of a fiber laser. The numerical results show that the pure mode TE01 (99.99%) can be obtained. In the case of the passive fiber, Gaussian light beams with suitable shift distance from the center core are coupled into the fiber. The results indicate that only the mode TE01 remains with the increasing propagation distance.
ABSTRACT
An anamorphic beam concentrator for linear laser-diode (LD) bar is presented. It consists of a tapered SiO(2)-rod with skewed and curved surface. The principle and applicability of this device are numerically investigated by ZEMAX and experimentally illustrated for the specific example of the linear LD bar. Results show that a relative symmetrical output beam spot is produced at the output facet of the rod and the intensity and spatial fluctuations in the input beam are compensated at distance of 20cm from the output facet.
