|
Fiber Bragg grating as a new kind of passive photonic devices , it has a low insertion loss , small size , low cost , and is not sensitive to the polarization , and ordinary optical fiber connection and simple optical memory and can slow light effect optical buffers and optical sensors are widely used in the field of optical fiber communication and optical fiber sensing has become one of the hot spots of the past decade the field of optics research . In this paper, the numerical calculation method to study the core radius , core index , the relative refractive index difference , the the DC effective refractive index of the change , the modulation depth , the grating length and the grating period uniform fiber Bragg grating group delay and discussed in detail various parameters influence of the maximum value of the group delay , on top of this parameter adjustment to obtain the largest maximum group delay , and focus on analysis of its departure from the type of grating group delay and slow light slow light characteristics . The results show that : the group delay of (1) with the core radius, the effective refractive index change of the core refractive index , DC , the modulation depth, the grating length , and grating period increases continuously moving direction to the long wavelength , and with the relative refractive index difference the increase in the short wavelength direction movement. (2), core refractive index so that the group delay with wavelength curve moving maximum distance , and the effective refractive index change of the moving distance with the DC , modulation depth and the grating length is increased to increase , but with the core radius , and the core refractive index, the relative refractive index difference , and the grating period decreases . ( 3) At the same time the maximum value of the group delay with the relative refractive index difference , the DC effective refractive index changes , modulation depth and grating length increases , but with the increase in the core radius , the core refractive index and the grating period the large decrease , increase or decrease the amplitude of the different parameters have different 17μs maximum value of the group delay . (4 ) In particular, the class of the corresponding grating slow light with wavelength extension continue to decay , and after less than 0.01nm wavelength of from 17μs index attenuation as a value of 0, and a straight line parallel to the wavelength axis , i.e. that the uniform fiber the Bragg grating slow light was fast fading characteristics . These laws provide a theoretical reference for the design of new optical devices .
|