A photonic crystal fiber has been filled with a cholesteric liquid crystal. A temperature sensitive photonic band gap effect was observed, which was especially pronounced around the liquid crystal phase transition tem...A photonic crystal fiber has been filled with a cholesteric liquid crystal. A temperature sensitive photonic band gap effect was observed, which was especially pronounced around the liquid crystal phase transition temperature.展开更多
We report the design and analysis of a rod-type photonic crystal fiber with Er-Yb co-doped for the high power 1.5-μm band amplifier.The fiber structure is designed to be the 120-μm extreme large core diameter,300-μ...We report the design and analysis of a rod-type photonic crystal fiber with Er-Yb co-doped for the high power 1.5-μm band amplifier.The fiber structure is designed to be the 120-μm extreme large core diameter,300-μm inner cladding diameter,and 1.5-mm outer cladding diameter that ensure the single mode output during high power amplification.Both the continuous wave(CW) and pulsed amplification characteristics are analyzed based on the exact modeling and simulation under the designed geometry.The 4-mJ pulse energy and 400-kW peak power are obtained in theory,so the 1.5-μm band amplifier that achieves milojoule level pulse energy meanwhile keeping single mode is firstly designed.展开更多
Light trapping within waveguides is a key practice of modern optics,both scientifically and technologically.Photonic crystal fibers traditionally rely on total internal reflection(index-guiding fibers)or a photonic ba...Light trapping within waveguides is a key practice of modern optics,both scientifically and technologically.Photonic crystal fibers traditionally rely on total internal reflection(index-guiding fibers)or a photonic bandgap(photonic-bandgap fibers)to achieve field confinement.Here,we report the discovery of a new light trapping within fibers by the so-called Dirac point of photonic band structures.Our analysis reveals that the Dirac point can establish suppression of radiation losses and consequently a novel guided mode for propagation in photonic crystal fibers.What is known as the Dirac point is a conical singularity of a photonic band structure where wave motion obeys the famous Dirac equation.We find the unexpected phenomenon of wave localization at this point beyond photonic bandgaps.This guiding relies on the Dirac point rather than total internal reflection or photonic bandgaps,thus providing a sort of advancement in conceptual understanding over the traditional fiber guiding.The result presented here demonstrates the discovery of a new type of photonic crystal fibers,with unique characteristics that could lead to new applications in fiber sensors and lasers.The Dirac equation is a special symbol of relativistic quantum mechanics.Because of the similarity between band structures of a solid and a photonic crystal,the discovery of the Dirac-point-induced wave trapping in photonic crystals could provide novel insights into many relativistic quantum effects of the transport phenomena of photons,phonons,and electrons.展开更多
文摘A photonic crystal fiber has been filled with a cholesteric liquid crystal. A temperature sensitive photonic band gap effect was observed, which was especially pronounced around the liquid crystal phase transition temperature.
文摘We report the design and analysis of a rod-type photonic crystal fiber with Er-Yb co-doped for the high power 1.5-μm band amplifier.The fiber structure is designed to be the 120-μm extreme large core diameter,300-μm inner cladding diameter,and 1.5-mm outer cladding diameter that ensure the single mode output during high power amplification.Both the continuous wave(CW) and pulsed amplification characteristics are analyzed based on the exact modeling and simulation under the designed geometry.The 4-mJ pulse energy and 400-kW peak power are obtained in theory,so the 1.5-μm band amplifier that achieves milojoule level pulse energy meanwhile keeping single mode is firstly designed.
基金KX and ZH acknowledge financial support by the NSFC(60588502 and 11404087)ADB acknowledges financial support by the EPSRC of UK.
文摘Light trapping within waveguides is a key practice of modern optics,both scientifically and technologically.Photonic crystal fibers traditionally rely on total internal reflection(index-guiding fibers)or a photonic bandgap(photonic-bandgap fibers)to achieve field confinement.Here,we report the discovery of a new light trapping within fibers by the so-called Dirac point of photonic band structures.Our analysis reveals that the Dirac point can establish suppression of radiation losses and consequently a novel guided mode for propagation in photonic crystal fibers.What is known as the Dirac point is a conical singularity of a photonic band structure where wave motion obeys the famous Dirac equation.We find the unexpected phenomenon of wave localization at this point beyond photonic bandgaps.This guiding relies on the Dirac point rather than total internal reflection or photonic bandgaps,thus providing a sort of advancement in conceptual understanding over the traditional fiber guiding.The result presented here demonstrates the discovery of a new type of photonic crystal fibers,with unique characteristics that could lead to new applications in fiber sensors and lasers.The Dirac equation is a special symbol of relativistic quantum mechanics.Because of the similarity between band structures of a solid and a photonic crystal,the discovery of the Dirac-point-induced wave trapping in photonic crystals could provide novel insights into many relativistic quantum effects of the transport phenomena of photons,phonons,and electrons.
