Holographic reflection filters in photorefractive LiNbO/sub 3/ channel waveguides

Summary from only given. We investigate such holographic wavelength filters in Fe- and Cu-doped LiNbO/sub 3/ channel waveguides. LiNbO/sub 3/:Fe and LiNbO/sub 3/:Cu crystals are sensitive to light in the visible green or blue wavelength region, but show only little effects in the red or near infrared spectral region. Especially in the 1.3 /spl mu/m and 1.55 /spl mu/m wavelength band of optical communications no photorefractive effects have been observed for common continuous wave intensities. Permanent refractive-index gratings are generated by thermal fixing of holograms using two beam interference of an argon ion laser.