def main(return_final=False):
N = r_[2**21, 2] # Number of pixels (different resolution for demo)
DX = 60 * mm # physical size in the important direction
wavelength = 780 * nm # Wavelength
gaussian_size = 1.0 / sqrt(
2) * mm # 1/e Intensity width of beam; (note, it's not the 1/e^2)
L_propagate = 25 * mm # distance from initial lens to 2D-MOT
# grating parameters
grating_period = mm / 900
grating_lambda = 1200 * nm # for the blazed grating
######## END Param ##############
side_length = DX * r_[1, N[1] / float(N[0])] # physical size
####### Create grating
G = grating.phase.Blazed(grating_period / m, wavelength / m,
grating_lambda / m)
####### END Create grating
propagate = Propagate1D(N, side_length, window_size=511)
##### With the knife edge between the SLM (at SLM focus) relay:1,lens:1.
##### In this case, we relay the knife edge to the MOT and not the SLM plane.
F = Field(N, side_length / m, wavelength / m) # beginning field
F.gaussian_aperture(gaussian_size / m, 1e300)
G.apply(F)
if return_final:
F.forvard(L_propagate / m)
plot((F.value * F.value.conj()).real[:, N[1] / 2])
return F
else:
propagate(F, L_propagate / m, L_propagate / m / 75.)
print 'press enter to exit'
raw_input()
####### Create LG order dx = (2 / (N - 1.)) x = y = 3 * r_[-1:(1 + dx):dx] [xx, yy] = meshgrid(x, y) lg = lg.LG_xy(l=l, p=0, xx=xx, yy=yy, omega0=2 / sqrt(l)) # normalize lg; we only want the phase information lg /= abs(lg) #imshow (x,y,arg(lg)) ####### END Create LG order propagate = Propagate() F = Field(N, side_length, wavelength) F.gaussian_aperture(gaussian_size) F.axicon(axicon_angle, axicon_n1) #F4 = propagate(13.*cm, step_size, F3,0,0,4); F.forvard(7.5 * cm) F.axicon(axicon_angle, axicon_n1) print 'moving towards slm' #F.forvard(40*cm) propagate(F, z=40. * cm, dz=10 * cm) print 'applying slm' F.value[:] *= lg propagate(F, z=50. * cm, dz=2 * cm) print 'press enter to exit' raw_input()
#!/usr/bin/env python """ LightPipes for Python Optical Toolbox """ import common from lightpipes import Field from pylab import * phi = 178 * (pi/180.) F = Field(256, 512*15e-6, 780e-9) F.gaussian_aperture(.75e-3) F.axicon(phi, 1.5, 0e-6, 0) F.forvard(25e-2) imshow( abs(F.value)**2 ) show() F.axicon(phi, 1.5, 0e-6, 0) F.forvard(100e-2) imshow( abs(F.value)**2 ) show() #F.lens(-20e-2) #F.forvard(3e-2) # gsplot F7.F.*conj(F7.F);
return phi x = y = grid_dx * r_[-255.5:256:1.] [xx, yy] = meshgrid(x,y) torus_phase = tlens(xx,yy,R0,f_torus,wavelength) + phase_ring(xx,yy,R1,w1) propagate = Propagate() #print 'press enter to continue' #propagate.imshow( torus_phase ) #raw_input() # propagate the field from the SLM and take a look F = Field( N, side_length, wavelength) # initial field F.gaussian_aperture(w) # gaussian input F.circular_aperture(side_length/2.) # Iris in front of SLM F.value[:] *= exp(1j * torus_phase ) # apply SLM phase F.forvard(f_torus) propagate(F, z=f_torus, dz=f_torus/25.) print 'press enter to show final phase...' raw_input() propagate.imshow( angle(F.value) ) print 'press enter to show final intensity...' raw_input() propagate.imshow( (F.value * F.value.conj()).real ) print 'press enter to exit' raw_input()
