Abstract: An all-optical wavelength converter comprising an optical waveguide of regions having differing non-linear optical susceptibilities such that the regions are quasi phase matched. An optical pumping signal is introduced in the waveguide, either input from the outside or is locally generated from a lasing active layer in the waveguide. Light having a first frequency is input to the waveguide and interacts with the optical pumping signal via the non-linear susceptibility to create light having a second frequency. Each of the regions has a length of one coherence length. That is, the input light and the pump light fall out of phase by 180.degree. in one coherence length. The modulation of the non-linear susceptibility can be accomplished, by disordering the anisotropic material forming the non-linear waveguide, by inverting the anisotropic crystal structure, or by launching an acoustic wave onto the waveguide so that the compression of the material periodically varies the non-linearities.

Abstract: A semiconductor interference mirror principally comprising a large number of pairs (36) of semiconductor layers (38,40) having different dielectric constants and having optical thicknesses equal to one-quarter of the wavelength of light to be reflected. For example, the two semiconductors are InP and InGaAsP for reflecting 1.55-.mu.m light. However, every 10 to 15 periods in the mirror, the InP layer (44) is grown more slowly to a thickness that is an odd multiple of its usual quarter-wavelength thickness. Because indium is so mobile and binary composition is well defined, the binary InP layer replanarizes the growth, thus assuring a planar mirror. The faster growth rate for the majority of the mirror allows the mirror to be grown in a shorter time, thus reducing process variations.