Gaussian beam

The fundamental Gaussian beam

`E(r,z)=E_0 omega_0/{omega(z)} exp(-r^2/{omega(z)^2})exp(-ikz-ik r^2/{2 R(z)}+i k zeta(z))`


Parameters

wave length
`lambda` \(mm\)
beam waist
\(w_0\) \(mm\)
amplitude
\(E_0\) \(V/m\)
z-axis
z \(mm\)
r-axis
r \(mm\)

Output

frequency f

`c=lambda f`

wave number k

`k={2pi}/lambda`

waist to wave length ratio 

\(\frac{\omega}{\lambda}\)

Rayleigh range \(z_R\)

`z_R=1/2 omega_0^2 k`

beam width `omega(z)`

`omega(z)=omega_0 sqrt(1+(z/z_R)^2)`

wavefront curvature R(z)

`R(z)=z[1+(z_R/z)^2]`

Gouy phase `phi(z)`

`phi(z)=arctan(z/z_R)`

Beam divergency `theta`

`theta=lim_{z->infty}{omega(z)}/z=arctan(2/{omega_0 k})`

Max Intensity  `I_0`

`I_0=|E_0|^2/{2 eta}`

Total power `P_0`

`P_0=1/2 I_0 pi omega_0^2`

Itensity `I(r,z)`

`I(r,z)=I_0(omega_0/{omega(z)})^2 exp({-2r^2}/{omega(z)^2})`

power ratio p(r,z)

`p(r,z)=1-exp({-2r^2}/{omega(z)^2})`

Beam quality BPP

`BPP=theta*omega_0`

Electric field E(r,z)

`E(r,z)=E_0 omega_0/{omega(z)} exp(-r^2/{omega(z)^2})exp(-ikz-ik r^2/{2 R(z)}+i k zeta(z))`