parameters.txt

cudos实例

	!       CUDOS Fibre Software sample parameter file
! This parameter file is for finding the fundamental mode of 
! a simple fibre consisting of a single hexagon of air cylinders in 
! a dielectric background with refractive index 1.45
! The structure is defined in the parameter file, and
! symmetries are used to reduce the problem.
! all internal parameters are adjusted automatically.
!
! First define the structure :

pitch=6.75d0			! center to cetner distance of the air cylinders
cylinder index=(1.d0,0d0)	! air cylinders
cylinder radius=2.5d0		! radius of cylinders
matrix index=(1.45,0d0)		! background refractive index
Nr=1				! Number of rings
MNr=1				! The core consists of only one missing cylinder 
no cladding			! The air cylinders are not surrounded by a jacket or a cladding
no jacket
build fibre			! compiles the above parameter into a structure

! define physical parameters

lambda=1.45			! sets the wavelength

! ask the software to find all internal parameters :

suggest n_eff range=fundamental		! finds the range of effective indices where the 
					! fundamental mode should be
suggest order=close cylinders		! suggest appropriate Fourier Bessel series  truncature parameter
					! with extra care given that the cylinders are relatively close

! save the structure to symhex.txt
! note that we save the structure after having defined the appropriate
! Fourier Bessel series truncation order since this
! parameter is saved with the structure

save fibre=symhex.txt

! Now find the modes

search modes				

! end of parameter file
end