Fabrication of low-cost planar wavelength-selective optical add-drop multiplexer by employing UV photosensitivity

A 2 x 2 optical add-drop multiplexer has been fabricated by exclusive use of the UV photosensitivity effect in defining the waveguide patterns and Bragg pattern without using any etching process on the multilayered slab structure prepared by a single session of flame hydrolysis deposition process. That is, the waveguide patterns were written by direct writing of a focused UV beam and, subsequently, the periodic grating was imprinted on the plate by a broad UV exposure over a phasemask. The add and drop efficiencies measured at the Bragg wavelength were 25 and 20 dB, respectively.