The analytical expression for the reflection-maximum wavelengths of the uniform fiber-grating F-P cavity is derived and explained by introducing equivalent F-P cavity length from its work principle,the reflection peak gap and the resonance peak numbers of the main band width are also obtained.

Meanwhile,we also conduct an experiment on the change of luminous intensity,luminous flux and peak wavelength with current and time.

Different shifts of peak wavelengths of blue and red LEDs were studied by measuring the two kinds of LEDs under DC and pulse currents,and it demonstrates that it is the heat and polarization effects that influence the shifts of peak wavelengths.

Peak wavelength,bandwith,domain wavelength,and centroid wavelength are factors affecting on light color of LED.

Effect of the fiber grating length on its peak reflectivity;

The influence rules of writing parameters on the peak reflectivity and reflective bandwidth were investigated by(using) Matlab.

But the stitching errors of electron-beam written phase masks always occur between neighboring sections,which can impact the reflectivity fluctuation of chirped Fiber Bragg Gratings (FBGs).

Moreover,by utilizing the back-reflection-peak-wavelength method,the wavelength to be added and dropped is located within the wav.