| 摘要 |
PURPOSE:To obtain a small-size and high-performance waveguide type filter with simple and small-size constitution, by controlling forms and refractive index modes of crossing waveguides. CONSTITUTION:A metallic impurity such as Ti is diffused on an electro-optic crystal such as a lithium niobate substrate 1 to form a main waveguide 2 and a branch waveguide 3 having a width of 10mum, respectively. A profile of the refractive index and a crossing angle of a crossing part 4 are selected properly to allow the laser beam of He-Ne or the like incident from the wavetuide 2 to go straightly to a branch path 2' or branch to a branch path 3'. Thus, a small- size and high-performance waveguide type filter is obtained. |
