vswf.bbp: Beam Shape Coefficient for Circularly polarized Bessel Beam

In wendellopes/rvswf: RVSWF: Expansion in Vector Spherical Wave Functions written in R

Description

Beam Shape Coefficient for Circularly polarized Bessel Beam

Usage

vswf.bbp(gama, kz, xo, yo, zo, lmax, M, s, p, code = "C")

Arguments

gama	The transversal component of the wave vector γ.
kz	The longitudinal component of the wave vector k_z.
xo	The position x at which the expansion is performed.
yo	The position y at which the expansion is performed.
zo	The position z at which the expansion is performed.
lmax	The maximum value of l in the expansion.
M	Order of the Bessel Beam.
s	Chirality of the Bessel Beam (S=\pm 1).
p	Polarity of the Bessel beam (S=\pm 1).

Details

Calculate the Beam Shape Coefficients for the partial wave expansion in Vector Spherical Wave Functions.

Value

The Beam Shape Coefficients for a Circularly polarized Bessel Beam.

See Also

vwfd.bbp, vswf.bbp, vswf.pwd.

Examples

lambda=.5e-6            # Propagating wavelength
a<-8*lambda             # Size x of the waveguide (Rectangular Wave Guide)
b<-8*lambda             # Size y of the waveguide (Rectangular Wave Guide)
l<-6*lambda             # Size z of the waveguide (Rectangular Wave Guide)
M<-5                    # x wavefield mode
N<-4                    # y wavefield mode
S<--1                   # Chirality
P<- 1                    # Mode (+/- 1)
# Wave Field Parameters
k=2*pi/lambda           # Propagating wavenumber
kx<-M*pi/a              # x component of the wavevector
ky<-N*pi/b              # y component of the wavevector
gama<-sqrt(kx^2+ky^2)   # gama component of the wavevector
kz<-sqrt(k^2-gama^2)    # z component of the wavevector
TM<-ifelse(P==-1,TRUE,FALSE)
#-------------------------------------------------------------------------------
# Geometry of the calculations
#-------------------------------------------------------------------------------
NPX<-4*50+1
NPY<-4*60+1
NPZ<-4*20+1
dx<-2*a/(NPX-1)
dy<-2*b/(NPY-1)
dz<-2*l/(NPZ-1)
x<-seq(-a,a,by=dx)
y<-seq(-b,b,by=dy)
z<-0
#-------------------------------------------------------------------------------
lmax<- 80 # Number of partial waves to sum (for some l we have 2l+1 values of m)
#-------------------------------------------------------------------------------
# POSITION AT WHICH THE EXPANSION WILL BE PERFORMED  (REFERENCE SYSTEM)
#-------------------------------------------------------------------------------
# ARBITRARY: We select two points, the is for the origin of the expansion,
#            the second is for the test, that must have be move to the new
#            system of coordinates x'=x-xo
xo<-yo<-zo<-0
x<-sample(x,1)
y<-sample(y,1)
#-------------------------------------------------------------------------------
# BSC CALCULATIONS
#-------------------------------------------------------------------------------
BBP<-vwfd.bbp(P,M,S,gama,kz,x+xo,y+yo,z+zo)  # WAVE FIELD DEFINITION
BSC<-vswf.bbp(gama,kz,xo,yo,zo,lmax,M,S,P)   # BEAM SHAPE COEFFICIENTS
PWE<-vswf.pwe(k,x,y,z,lmax,BSC$GTE,BSC$GTM)  # PARTIAL WAVE EXPANSION
#-------------------------------------------------------------------------------
# VALUES
#-------------------------------------------------------------------------------
cat("Distance x from origin in wavelength (from ",-a/lambda,"to ",a/lambda,"):",x/lambda,"\n")
cat("Distance y from origin in wavelength (from ",-b/lambda,"to ",b/lambda,"):",y/lambda,"\n")
df<-data.frame(
   PWE=c(PWE$Em,PWE$Ez,PWE$Ep,PWE$Hm,PWE$Hz,PWE$Hp),
   BBP=c(BBP$Em,BBP$Ez,BBP$Ep,BBP$Hm,BBP$Hz,BBP$Hp),
   row.names=c("Em","Ez","Ep","Hm","Hz","Hp")
   )
df$DIF<-df$PWE-df$BBP
print(df)

wendellopes/rvswf documentation built on May 4, 2019, 4:19 a.m.