Optical fiber sampling optical grating and planar optical wave guide sumpling grating

Abstract

An optical fiber sampling grating and a planar optical waveguide sampling grating, the refractive index of the grating along the core / waveguide axis is periodically distributed, and is represented by the product of the refractive index function and the sampling function of the mother grating; the mother grating The refractive index function is δn(z)=δn0Sin〔4πnez / λB〕, wherein: δn0 is the refractive index variation range of the grating, ne is the effective refractive index of the fiber core / waveguide, and λB is the Bragg wavelength of the grating; the sampling function The Fourier transform has the characteristics of bilateral symmetry and linear or approximately linear change, using functions such as Sinc2, second-order rational functions or Sinc-Sinc2 combination functions. The Sinc2 sampling fiber grating and Sinc2 sampling planar waveguide grating have a linear or approximately linear delay spectrum envelope, and each wavelength channel is symmetrical, can produce a large number of constant delay steps less than 1ps and can allow signal broadband work .

Description

technical field [0001] The invention relates to a photon element, in particular to a fiber sampling grating and a planar optical waveguide sampling grating used as a high-resolution and high-speed signal processor. Background technique [0002] In many cases of communication, signals take different times to travel through different channel media and exhibit different delays (delay is a relative relationship in time) when reaching the next receiver or processor. ps(10 -12 Seconds) short delays have many important applications, such as high-resolution delayed signal processing in microwave phased array beamforming. THz optical sampling is generated by means of multi-wavelength light sources, thereby realizing many high-speed and broadband signal processing functions. Traditional electronic delay lines are only capable of generating ns(10 -9 second) level of short delay, and cannot work in broadband due to frequency dependence. The general fiber delay line overcomes the dif...

AI Technical Summary

Problems solved by technology

Since 1ps corresponds to a fiber length of 0.2mm, writing gratings each time may cause errors caused by adjustments, so when the number of gratings to be written is large, this problem is more serious, so superimposed gratings write gratings multiple times Manufacturing characteristics determine that it is difficult to achieve a large and constant 1ps delay with this method

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