Generation of CW millimeter wave signals in a lithium niobate nonlinear optical waveguide using modulated optical input

The generation of CW millimeter wave signals is observed in a LiNbO₃ nonlinear optical waveguide. Optical light that has two frequency components is introduced into an optical waveguide, and the millimeter waves which are generated are obtained from the terminal connected to the metallic traveling waveguide. This configuration is made with a LiNbO₃ commercial phase modulator. Millimeter waves are generated at frequencies up to 40 GHz. This is the first report of CW millimeter wave generation in a nonlinear ferroelectric waveguide, to our knowledge. A comparison of the measured signal levels with theoretically estimated ones is discussed.