Asymmetric Y junctions allow the development of a new class of optical frequency mixers that utilize higher-order waveguide modes for signal processing. We measure high-contrast (>30dB) mode sorting in asymmetric Y junctions by use of a novel technique: efficient TM<sub>00</sub> , TM<sub>10</sub> , and TM<sub>20</sub> mode mixing in a periodically poled lithium niobate waveguide. We also demonstrate an odd-to-even mode wavelength converter capable of spectral inversion without offset or bidirectional wavelength conversion.
© 2004 Optical Society of America
(070.4340) Fourier optics and signal processing : Nonlinear optical signal processing
(130.2790) Integrated optics : Guided waves
(190.2620) Nonlinear optics : Harmonic generation and mixing
(190.4360) Nonlinear optics : Nonlinear optics, devices
(230.4320) Optical devices : Nonlinear optical devices
Jonathan R. Kurz, Jie Huang, Xiuping Xie, Takashi Saida, and Martin M. Fejer, "Mode multiplexing in optical frequency mixers," Opt. Lett. 29, 551-553 (2004)