The reflectance as a function of wavelength is computed for an index modulation
Bragg grating, the computations are performed on your own computer (a Java
Applet is automatically loaded) and rely on the successive reflections
and transmissions while the beam is crossing each layer. Multiple complex
matrix multiplication is performed for each wave length.
Various parameters may be changed :
incidence angle (0° means in the direction of the grating vector),
high refractive index
low refractive index
apodization : enter "no", "linear" or "sine"
number of periods ...
The "hold" button allows you to keep previous computation, while you are experimenting
other paramameters.