Patent ID: 7526209

Claim:
An optical frequency shift keying modulator comprising: a first sub Mach-Zehnder waveguide MZ A ; a second sub Mach-Zehnder waveguide MZ B ; a main Mach-Zehnder waveguide MZ C including said MZ A and said MZ B , and including a light input portion and a modulated light output portion; a first RF electrode, RF A electrode, inputting a radio frequency RF signal to two arms composing said MZ A ; a second RF electrode, RF B electrode, inputting the RF signal to two arms composing said MZ B ; and a third RF electrode, RF C electrode, of a traveling-wave-type electrode for high speed optical phase switch at the junction of the pair of sub Mach-Zehnder waveguides MZ A and said MZ B by adjusting the bias voltage of the RF C electrode, thereby controlling a frequency of the light outputted from said output portion; wherein the voltage of the RF signal inputted to the RF C electrode of the traveling-wave-type electrode corresponding to the RF signal is controlled, so that the frequency of the light outputted from the output portion is modulated, wherein the signal inputted to said RF C electrode has a frequency component greater than 500 MHz.