from numpy import pi

L = 140e-3
R = 0.325
l = 1542e-9
g = 1-L/R
w0cp = ((L*l)/pi*(g/(1-g))**.5)**.5
#w0cc = ((L*l)/pi*((1+g)/(4*(1-g)))**.5)**.5
#w0ccl = ((L*l)/pi*(R/(2*L))**.5)**.5

print('waist cp = %e m'%w0cp)
#print('waist cc = %e m'%w0cc)
#print('waist ccl = %e m'%w0ccl)