
		Fresnel reflectivity
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This program calculates the flux of light I(t) reflected from a 
step plasma profile.
The laser pulse is assumed to have rectangular shape.

Input parameters are 
	- plasma frequency in units of the laser frequency
	- incident laser amplitude (= lpic++ amplitude a0)
	- angle of incidence
	- polarization (s or p)
	- pulse duration in laser cycles
	- number of time steps per cycle
	- output path
These parameters are entered by editing the input file 'input.fresnel'.

Results are written to file 'reflex', 'reflex-avg' and 'reflex-int'.
	'reflex' : reflected intensity as a function of time
	'reflex-avg' : cycle-averaged reflectivity ( <I(t)>/I0 )
	'reflex-int' : integrand for the numerical integration, 
                       only for those who are very much interested!                       

Notice: To compare the reflected flux with lpic++ results, you have 
	to shift the reflected flux in time corresponding to the 
	time the laser light needs for reaching the surface and 
	returning to the box boundary.
