| 摘要 |
The preset invention relates to a transmission-type tunable optical filter which emits a certain wavelength of an element of light in a broadband incident to one end portion of an optical waveguide to an other end portion of the optical waveguide using long period grating instead of an existing Bragg grating. According to the present invention, the transmission-type tunable optical filter comprises: the optical waveguide including a cladding, a first core, and a second core which are encircled by the cladding and are separated from each other; a first long period grating formed in a first optical waveguide region wherein the first core of the optical waveguide is located; a first heater located on the optical waveguide in the first optical waveguide region, adjusting an optical period of the first long period grating by a thermo-optic effect; a second long period grating formed in a second waveguide region wherein the second core of the optical waveguide is located; and a second heater located on the optical waveguide in the second optical waveguide region, adjusting an optical period of the second long period grating by the thermo-optic effect. The certain wavelength of an element of light in the broadband, which is incident to one end portion of the optical waveguide and is emitted in a core mode of the first core, is converted to be in a cladding mode as the optical period of the first long period grating is adjusted by the first heater. The wavelength element, having converted to be in the cladding mode, is converted to be in a core mode of the second core; and is emitted to an other end portion of the optical waveguide as the optical period of the second long period grating is adjusted by the second heater. |
