A novel all-optic tunable long-period grating using a unique double-cladding layer

In this paper, a novel all-optic tunable filter based on long-period gratin g (LPG) with a unique double-cladding layer structure is implemented. The L PG that has an ultra-thin silica inner cladding layer and a dye-doped liqui d crystal outer cladding layer is tuned by photochemical driving liquid-cry stal molecular reorientation. The unique feature of this tunable filter is that there is no contact electrodes required, which may make the fabricatio n of tunable filter easier. (C) 2001 Elsevier Science B.V. All rights reser ved.