Ultra-low Confinement Loss Research Articles

Advanced design and optimization of single mode photonic crystal fibers

This paper proposes a combination of differential evolution (DE) and estimation of distribution algorithm (EDA) to design photonic crystal fiber structures with desired properties over the C communication band. In order to determine the properties of PCFs such as dispersion, dispersion slope and loss, an artificial intelligence method, the Nero-Fuzzy system, is applied. In addition, a special cost function which simultaneously includes the confinement loss, dispersion and its slope is used in the proposed design approach. The results revealed that the proposed method is a powerful tool for solving this optimization problem. The optimized PCF exhibits an ultra low confinement loss and low dispersion at 1.55 µm wavelength with a nearly zero dispersion slope over the C communication band.

Ultrahigh Birefringent Photonic Crystal Fiber With Ultralow Confinement Loss

A photonic crystal fiber (PCF) with circular air holes in the fiber cladding and elliptical air holes in the fiber core is proposed. According to calculation, both ultrahigh birefringence (larger than 0.01) and ultralow confinement loss (less than 0.001dB/km) can be achieved simultaneously over a large wavelength range for a PCF with only four rings of circular air holes in the fiber cladding. The confinement loss in this PCF can be effectively reduced while the birefringence almost remains the same. The proposed design of the PCF is a solution to the tradeoff between the birefringence and the confinement loss for the originally reported highly birefringent elliptical-hole PCF. Moreover, an approach to modify the effective index of fiber core is also suggested in this letter