LIQUID CRYSTAL VARIABLE WAVELENGTH FILTER UNIT, AND DRIVING METHOD THEREOF

摘要

A liquid crystal variable wavelength filter device applicable to a Wavelength Division Multiplexing WDM communication system and optical network using optical fiber, and a driving method thereof. The liquid crystal variable wavelength filter device 130 includes a band pass filter 111 formed of a dielectric multi-layered film inclined by a predetermined angle alpha between a first liquid crystal beam deflector 101 and a second liquid crystal beam deflector 103 and sandwiched by a first wedge prism 121 and a second wedge prism 123. A first drive device 141 is connected to the first liquid crystal beam deflector 101, and a second drive device 143 is connected to the second liquid crystal beam deflector 103. The wavelength is selected by allowing the outgoing angle to the band pass filter to be variable by the liquid crystal beam deflector.