set terminal postscript eps color enhanced font "Helvetica,16pt" size 8.6cm,6cm
set output "snr.eps"

set logscale x
set logscale y
set xr [10**-14:10**-9]
set yr [10**-4:1]
set xl "Coherence Time {/Symbol t}_{c} [s]"
set xtics auto nomirror
set ytics 1,0.1,0.01,0.001,0.0001,0.00001 nomirror
#set tics scale 2
set yl "Visibility^{2}"
set xl offset 0,0.3
set yl offset 3,0
set format x "10^{%T}"
%set format y "%2.1f"

set logscale x2
set x2l "Optical Bandwidth {/Symbol Dl} [nm]"
set x2r [100:0.001]
set x2tics 
set x2l offset 0,-0.5

set logscale y2
set y2l "Signal-to-Noise Ratio" 
set y2r [108.93*10**-4:108.93*1] 
set y2tics
set y2l offset -1.5,0

set label 1 "{/Symbol t}_{c} << {/Symbol t}_{t}" at 4*10**-14,0.01
set label 2 "{/Symbol t}_{c} < {/Symbol t}_{t}" at 3*10**-12,0.01
set label 3 "{/Symbol t}_{c} > {/Symbol t}_{t}" at 1*10**-10,0.01

#set label 3 "{/Symbol t}_{t} = \n 40 ps" at 10*10**-12,0.9
#set label 4 "{/Symbol t}_{c} = \n 0.5 ns" at 0.92*10**-10,0.92

f(x) = x<= 40*10**-12 ? 1:0/0
g(x) = x>= 40*10**-12 ? 1:10/0

vnofilter(x) = f(x)*0.45*(1+exp(-2))*x/(40*10**-12)
vfilter(x) = g(x)*0.45*(1+exp(-2*abs(40*10**-12)/x))
#v(x) = exp((-40*10**-12)/x)

set arrow from 10**-12,0.0001 to 10**-12,1 nohead lc -1
set arrow from 40*10**-12,0.0001 to 40*10**-12,1 nohead lc -1
#set arrow from 0.5*10**-9,0 to 0.5*10**-9,1 nohead lc 2

plot vfilter(x) w l lt 1 lc 1 lw 2 notitle, vnofilter(x) w l lt 1 lc 1 lw 2 notitle