convertLaser

Miscellaneous conversions for laser fields

Syntax

convertLaser is defined as an abstract class with conversion defined by static methods with the following generic syntax

cVal = convertLaser.old2new(val)
cVal = convertLaser.old2new(val,___)

with "old" and "new" the parameters being converted. Some conversions require or allow for optional additional parameters, see below.

Description

Each parameter conversion is defined between atomic units and another identify unit, see below. Additional unit conversions can be performed with the convertUnit class.

Intensity and electric field amplitude

Conversion between the laser intensity $I _0$ , in watt per square centimeters [W/cm $^2$ ], and the electric field amplitude $E _0$ , in atomic units [a.u.].

E0 = convertLaser.intensity2amplitude(I0)
I0 = convertLaser.amplitude2intensity(E0)

The conversion can also include an optional ellipticity $\varepsilon$

E0 = convertLaser.intensity2amplitude(I0,elpt)
I0 = convertLaser.amplitude2intensity(E0,elpt)

By default, the conversion is done for linear polarization, i.e., $\varepsilon =0$ , and defined as

$$ E_0 ~\textrm{[a.u.]}=5.33803\times {10}^{-9} \sqrt{\frac{I _0 ~{\textrm{[W/cm}}^2 \textrm{]}}{1+\varepsilon^2 }}. $$

If specified, the ellipticity parameter should be either scalar -- same ellipticity is applied to all parameters being converted -- or have the same shape as the input intensity/amplitude -- each entry with its own ellipticity. See example below.

Field wavelength and frequency

Conversion between the field wavelength $\lambda$ , in meters [m], and its frequency $\omega$ , in atomic units [a.u.].

w = convertLaser.wavelength2frequency(f)
f = convertLaser.frequency2wavelength(w)

The conversion is defined as

$$\omega ~\textrm{[a.u.]}=\frac{2\pi c}{4.1341\times 10^{16} \lambda ~\textrm{[m]}}~~\textrm{with}~~c=2.99792458\times 10^8. $$

Examples

Intensity and electric field amplitude

Convert electric field intensity to amplitude using default linear polarization

E0 = convertLaser.intensity2amplitude(1e14)

Convert circularly polarized electric field intensity to amplitude

E0 = convertLaser.intensity2amplitude(1e14,1)

Convert multiple intensities to their amplitude, all with the same ellipticity

E0 = convertLaser.intensity2amplitude([1e14,1e15,1e16],0.5)

Convert multiple intensities, each with their own ellipticity, to their amplitudes

E0 = convertLaser.intensity2amplitude([1e14,1e15,1e16],[0,0.5,1])

See also

convertUnit