Fused coupler forming with a single-mode fiber (SMF) and a photonic crystal fiber (PCF) is one of the solutions for optical coupling from a light source to a PCF. In this paper, we presented coupling characteristics of a fused fiber coupler formed with an ordinary SMF and a PCF having air hole collapsed taper. A prototype of SMF-PCF coupler with air hole collapsed taper was fabricated using CO2 laser irradiation. The coupling efficiency from SMF to PCF was −6.2 dB at 1554 nm wavelength in the fabricated coupler. The structure of the SMF-PCF coupler to obtain high coupling efficiency was theoretically clarified by beam propagation analysis using an equivalent model of the coupler with simplification. It was clarified that appropriately choosing the prestretched or etched SMF diameter and the length of air hole collapsed region was effective to obtain high coupling efficiency that was a result of high extinction ratio at cross port and low excess loss. We also demonstrated that the diameter of prestretched SMF to obtain high coupling efficiency was insensitive to the air hole diameter ratio to pitch of the PCF in the air hole collapsed SMF-PCF coupler.
Zinc is one of the important material in human blood because of its effect in defensive system work for properly and it plays an important role in growth, wound healing Medically zinc concentration effect directly in skin health so it's important to make a sensor for discover zinc and its concentration change in human blood for each of male and female. Optical fibers are used as a sensor for detecting zinc and its concentration by transmitted laser signal through the optical fiber by using different types (single mode fiber SMF, photonic crystal fiber PCF) by studying the results of output laser the detection can be seen for zinc concentration change, the design of small PCF which the same LMA_10 but smaller in its radius of core and cladding even the distance between cores. The smallest PCF size has the best detection for all zinc concentration change in blood all that was done by comsol Multiphysics 5.4 simulation program
This paper presents a numerical analysis and comparison on the performance of multi-pump gain-flat Raman amplifiers based on triangular photonic crystal fiber and conventional fiber. It is demonstrated that the extra 5.93 dB Raman net gain can be achieved in the L-band when PCF acts as Raman gain medium. The noise performance of the two amplifiers are also calculated and compared. Comparison with the data of published literature was also carried out to verify our analysis. The results showed that PCF is the appropriate candidate for high gain Raman amplifiers.
A novel type of highly birefringent photonic crystal fiber is designed, which yields to promise a very large birefringence [Formula: see text] with flat dispersion at the operating wavelength 1550 nm. By employing the FDTD method, other properties, such as dispersion, walk-off effect and [Formula: see text]-parameters, are highly optimized using lattice period of air holes.
Coupling Characteristics of Fused Optical Fiber Coupler Formed with Single-Mode Fiber and Photonic Crystal Fiber Having Air Hole Collapsed Taper