A novel cross-phase modulation scheme that permits measurement of the
optical Kerr coefficient in non-polarization-preserving fiber is prese
nted. The scheme is based on a Michelson-type interferometer in which
one mirror is replaced by an orthoconjugated mirror. The use of this d
evice leads to an effective insensitivity with respect to the state of
polarization of the probe and pump beams. (C) 1996 Optical Society of
America.