Optical isolator with polarization dispersion and differential transverse deflection correction

An optical isolator for isolating an optical signal source from reflected signals, comprising:

• main polarization discrimination means for receiving and polarizing an optical signal from the optical signal source such that the optical signal upon entering said main polarization discrimination means is polarized and dispersed into ordinary and extraordinary rays that exhibit differential transverse deflection and differential propagation delay relative to one another while propagating through said main polarization discrimination means;
• and
• auxiliary polarization discrimination means disposed proximate said main polarization discrimination means and through which said ordinary and extraordinary rays from said main polarization discrimination means propagate for refractively adjusting the differential transverse deflection and differential propagation delay of the ordinary and extraordinary rays as said rays propagate through said auxiliary polarization discrimination means so as to minimize the differential transverse deflection and differential propagation delay of the ordinary and extraordinary rays as said rays propagate through said optical isolator, said auxiliary polarization discrimination means being selectively dimensioned so as to predeterminedly adjust the differential propagation delay of said rays as the rays propagate through the auxiliary polarization discrimination means, and said auxiliary polarization discrimination means having surfaces through which said rays propagate and selectively inclined at a selected tilt angle .theta. relative to a path of propagation of said rays to predeterminedly adjust the differential transverse deflection of said rays as the rays propagate through said auxiliary polarization discrimination means:
• wherein said tilt angle .theta. is defined by ##EQU3## wherein .DELTA.y is the differential transverse deflection occurring in said main polarization discrimination means, n.sub.o and n.sub.e are indices of refraction effective in said auxiliary polarization discrimination means for said ordinary and extraordinary rays respectively, and L is an effective thickness of said auxiliary polarization discrimination means.