Jacobson, Price, Holman & Stern, PLLC
Grating-assisted vertical codirectional coupler having pair grating structure
 The present invention relates to an optical filter for selecting a wavelength to be used in an optical communication and optical switching equipment and, more particularly, to an optical filter in order to reduce a sidelobe deteriorating its characteristics. The optical filter according to the present invention includes a plurality of pair gratings formed in a cladding layer, wherein a period of the grating pairs is constant throughout the optical filter, wherein the pair gratings are divided into two unit gratings, and wherein intervals between unit grating within pair grating are spatially different. 
Electronics and Telecommunications Research Institute Korea Telecom
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Seung Won Chan Yong Dug Bong Jeong Soo
Lee Park Kim Kim