Numerical analysis of optical propagation characteristics of side-polished photonics crystal fiber

Abstract

In order to design new all optical fiber devices based on side-polished photonics crystal fiber (SPPCF), we analyzed optical propagation characteristics of SPPCF with different polished parameters, such as residual radius R, polished length z along the PCF, and azimuth. The optical transmittance and the evolution of transverse mode along the SPPCF with a hexagonal arrangement of air hole on cross section were calculated and analyzed. The simulation shows that optical power transmittance in SPPCF decreases and oscillates with the increase of polishing length z. The evolutions of the transverse mode for different polishing azimuth become significant different from each other when the residual radius is polished to be less than 0.5 $\upmu$m. In the polished area, the propagation mode $\hbox {LP}_{01}$, which is originally launched at the input of SPPCF, will spread out and be coupled to high order propagation modes and radiation mode. The shorter the R is, the smaller the optical power transmittance of SPPCF will be. The optical transmittances of SPPCF as a function of R is very dependent on the polishing azimuth when R is in range from $-$0.5 to $+$0.5$\upmu$m The results will provide meaningful reference in design and fabrication of SPPCF-based devices.