Time
1 au = 24.1889 asec
1fsec = 41.341 au
Intensity and Amplitude
I=1/2 εc E2
E(1 au)=5.142 21 x 109 [V/cm]
I(1 au)=3.509 445 x 1016 [W/cm2]
I[W/cm2] = 1.327 207 x 10-3 E[V/cm]2
E[V/cm]=27.449 256 \sqrt I[W/cm2]
ex) 1012 [W/cm2] = 27.449 256 x 106[V/cm]
=
0.005 338 027 au (in Amplitude)
Wavelength and photon energy
E = hc/λ=h¯ ω
E(eV) = 1239.85 λ[nm]
ex) λ= 800 nm
1239.85/800 = 1.54 9812 eV
Pulse duration
exp (-2 ln 2 (t/T)2): T=FWHM
= exp (- {\sqrt(2ln2) t/T}2)
= exp (- (1.177 410 t/T)2)
Texp= T (FWHM)/1.177 410
Period
T=λ/c
ex) 800nm/2.997 92 x 108 m/s = 2.668 52 fsec
Ponderomotive energy
< p2/2m > = <(eA/c)2/2m>
Up=e2 E2/4mω2
Up[eV]=9.337 38 x 10-20 I[W/cm2] λ2[nm]
For 800 nm,
Up[eV]=59.759 2 x I[PW/cm2]
Keldish Parameter,
\gamma=\sqrt(Ip/2 Up)
For hydrogen, 800 nm,
\gamma=\sqrt(6.8029/Up[eV]) =0.3374/sqrt(I[PW/cm2])
Minimum No. of Photons,
(Ip+Up)/h¯ ω
Up/h¯ ω
Up/(h¯ ω) =e2 E2/4mω2/(h¯ ω) =e2
E2/4mω3h¯