Patent ID: 6522456
Filing Date: 2003-02-18
Classification: G02F

Abstract:
An apparatus for filtering light comprising:a beam splitter that splits an optical input into polarization components along separate optical paths; a first electro-optic device that receives the polarization components of the optical input along separate paths, the first electro-optic device including electrodes across which a first voltage is applied to adjust a corresponding wavelength transmission characteristic of the device having an attenuation profile for filtering the optical input wherein the attenuation profile is approximately sinusoidal over a range of wavelengths, a first section of the first electro-optic device positioned between the electrodes having an adjustable birefringence depending on the applied first voltage, wherein phase characteristics of the attenuation profile are adjusted based on the first voltage applied across the electrodes in the first section of the first electro-optic device and a second section of the first electro-optic device positioned to receive optical components along the separate optical paths including a material having a fixed birefringence for providing an optical bias for determining a period, T, of the corresponding wavelength transmission characteristic of the device, wherein the adjustable birefringence of the first section positioned between the electrodes is adjusted depending on the applied first voltage to select a wavelength shift of the corresponding wavelength transmission characteristic of the device; and an optical combiner that combines the optical components transmitted along separate optical paths through the first electro-optic device to produce a filtered optical output based on the sinusoidal attenuation profile due to the first and second sections.