WEIGHTED DISTRIBUTED-FEEDBACK STRUCTURE FOR ALL-OPTICAL BISTABLE DEVICES

We proposed to use a distributed feedback structure with a weighted co upling coefficient (W-DFB) in an all-optical bistable device in order to improve on-state transmittance and to reduce threshold intensity. T hrough numerical calculations, characteristics of the W-DFB structure were discussed compared with those of a conventional DFB structure. Th e W-DFB optical bistable device exhibits high on-state transmittance a nd low-threshold input intensity. Fabrication of the W-DFB structure w ith a periodicity of 169.8 Ma is demonstrated on a CdSxSe1-x-doped gla ss substrate by means of holographic exposure with a double-coated pho toresist and reactive ion etching in CHF3.