def fresnel(aperture, z=2, lambda1=660 * 10**(-9)):
aperturelist = [
'rectangle', 'doublerectangle', 'frame', 'doublecircle', 'ring'
]
if aperture.__type__ == 'circle':
n = aperture.__background__
d = aperture.__d__
D = aperture.__d__ * aperture.__scale__
scale = aperture.__scale__
Nf = D**2 / (4 * lambda1 * z)
#Fresnel number. Smaller is better for single-DFT Fresnel
print("Fresnel number = ", Nf)
elif aperture.__type__ in aperturelist:
print(aperture.__type__)
n = aperture.__background__
scale = aperture.__scale__
else:
print("No this kind aperture for fresnel diffraction")
x1 = __np__.linspace(-n / 2 + 1, n / 2, n)
[x, y] = __np__.meshgrid(x1, x1)
# Single-DFT
e1 = __np__.exp(1j * 2 * __np__.pi / lambda1 * (x**2 + y**2) / 2 / z *
((scale)**2))
diffraction = __np__.fft.fftshift(__np__.fft.fft2(aperture.__aper__ * e1))
extent = n * scale
__tools__.__apershow__(diffraction, extent=extent)
return diffraction
def fresnel(aperture,z = 2,lambda1 = 660*10**(-9)):
aperturelist = ['rectangle','doublerectangle','frame','doublecircle','ring']
if aperture.__type__ == 'circle':
n = aperture.__background__
d = aperture.__d__
D = aperture.__d__*aperture.__scale__
scale = aperture.__scale__
Nf = D**2/(4*lambda1*z); #Fresnel number. Smaller is better for single-DFT Fresnel
print("Fresnel number = ", Nf)
elif aperture.__type__ in aperturelist:
print(aperture.__type__)
n = aperture.__background__
scale = aperture.__scale__
else:
print("No this kind aperture for fresnel diffraction")
x1 = __np__.linspace(-n/2+1,n/2,n)
[x,y] = __np__.meshgrid(x1,x1)
# Single-DFT
e1 = __np__.exp(1j*2*__np__.pi/lambda1*(x**2+y**2)/2/z*((scale)**2))
diffraction = __np__.fft.fftshift(__np__.fft.fft2(aperture.__aper__*e1))
extent = n*scale
__tools__.__apershow__(diffraction, extent = extent)
return diffraction
def otf(self):
"""
Compute an aperture's otf
"""
print "-------------OTF---------------"
aperfft = __np__.fft.fftshift(__np__.fft.fft2(self.__aper__)) ** 2
aper_OTF = __np__.fft.fftshift(__np__.fft.fft2(aperfft))
__tools__.__apershow__(aper_OTF, extent=0)
return 0
def otf(self):
"""
Compute an aperture's otf
"""
print "-------------OTF---------------"
aperfft = __np__.fft.fftshift(__np__.fft.fft2(self.__aper__))**2
aper_OTF = __np__.fft.fftshift(__np__.fft.fft2(aperfft))
__tools__.__apershow__(aper_OTF, extent=0)
return 0
def fraunhofer(aperture, z = 2, lambda1 = 660*10**(-9)): """ Fraunhofer diffraction """ diffraction = 1j*__np__.exp(1j*2*__np__.pi/lambda1*z)/lambda1/z*__np__.fft.fftshift(__np__.fft.fft2(aperture.__aper__)) extent = aperture.__background__*aperture.__scale__ __tools__.__apershow__(diffraction, extent) return diffraction
def fraunhofer(aperture, z=2, lambda1=660 * 10**(-9)):
"""
Fraunhofer diffraction
"""
diffraction = 1j * __np__.exp(
1j * 2 * __np__.pi / lambda1 * z) / lambda1 / z * __np__.fft.fftshift(
__np__.fft.fft2(aperture.__aper__))
extent = aperture.__background__ * aperture.__scale__
__tools__.__apershow__(diffraction, extent)
return diffraction
def show(self):
"""
Show aperture figure
Output
------------------------------------
Aperture figure
"""
print "---------show aperture--------"
extent = self.__scale__ * self.__background__
__tools__.__apershow__(self.__aper__, extent)
def show(self):
"""
Show aperture figure
Output
------------------------------------
Aperture figure
"""
print "---------show aperture--------"
extent = self.__scale__ * self.__background__
__tools__.__apershow__(self.__aper__, extent)