Step-index profile

About: Step-index profile is a research topic. Over the lifetime, 3104 publications have been published within this topic receiving 53199 citations.

Reflection preventive film and manufacture thereof

Abstract: PROBLEM TO BE SOLVED: To prevent the reflection of the light of a surface of a transparent base board, and clearly read internal visual sense information by laminating a medium refractive index layer, a high refractive index layer and a low refractive index layer in order. SOLUTION: A reflection preventive film 10 is formed by laminating a medium refractive index layer 3, a conductive high refractive index layer 2 and a low refractive index layer 1 composed of an SiOx layer in order on a transparent base material film 5 through a hard coat layer 4. The medium refractive index layer 3 is constituted on the hard coat layer 4 by a coating of paint composed of a binder and ultrafine particulates having a refractive index not less than 1.5. There is the relationship of (2.20 > the high refractive index layer 2 of a refractive index > the medium refractive index layer 3 of a refractive index > the low refractive index layer 1 of a refractive index > 1.40). In a thickness of the respective refractive index layers, the low refractive index layer is 80 to 100nm, and the high refractive index layer 2 is 80 to 110nm, and the medium refractive index layer 3 is 55 to 70nm. An optical film thickness D(iD =n.d and (n) is a refractive index of the medium refractive index layer 3, and (d) is its thickness) is constituted so as to be set not more than a wave length of visible radiation.

Design of Refractive Index Profile for Multimode Optical Fibers with Low Differential Mode Delay

Abstract: This work presents an alternative method for design of refractive index profile for silica GeO2-doped graded-index multimode optical fibers 50/125 with low differential mode delay (DMD), providing equalization between group velocities of selected guided modes. Here the objective function is represented as a sum of squares of deviations between points of current iteration group velocity map, which has been calculated over modes with particular orders, and certain reference group velocity value. During the objective function formation it is proposed to take into account only selected guided modes, that depend on the type of laser source and launch conditions. In the given article we represent some results of introduced method approbation with following simulation of fiber optic link based on proposed multimode fibers with low DMD under the core geometry variations.

Optical phase modulator and optical equalizer using the same

Abstract: In an optical phase modulator, a substrate has electro-optical effect. An optical waveguide is formed in a surface portion of the substrate. A phase modulation section is provided on an input side to change a refractive index of the optical waveguide for phase modulation to input light. An adjustment section is provided on an output side to change a refractive index of the optical waveguide for elimination of polarization dependency of the phase-modulated light. In this case, the refractive index change rate in the phase modulation section and the refractive index change rate in the adjustment section may have different signs each other.

High Sensitivity Refractometer Based on Reflective Smf-Small Diameter No Core Fiber Structure

Abstract: A high sensitivity refractive index sensor based on a single mode-small diameter no core fiber structure is proposed. In this structure, a small diameter no core fiber (SDNCF) used as a sensor probe, was fusion spliced to the end face of a traditional single mode fiber (SMF) and the end face of the SDNCF was coated with a thin film of gold to provide reflective light. The influence of SDNCF diameter and length on the refractive index sensitivity of the sensor has been investigated by both simulations and experiments, where results show that the diameter of SDNCF has significant influence. However, SDNCF length has limited influence on the sensitivity. Experimental results show that a sensitivity of 327 nm/RIU (refractive index unit) has been achieved for refractive indices ranging from 1.33 to 1.38, which agrees well with the simulated results with a sensitivity of 349.5 nm/RIU at refractive indices ranging from 1.33 to 1.38.