Broadband monolithic acousto-optic tunable filter

Broadband monolithic acousto-optic tunable filters that combine a piezoelectric transducer array and an acousto-optic interaction medium in a single crystal have been investigated. A linearly chirped acoustic superlattice with an optical tuning range of lambda = 1.3-1.6 mu m was formed by domain inversion in LiNbO3. X-propagating longitudinal acoustic waves are excited in a crossed-field scheme by a rf E-y field applied to the superlattice and couple collinearly propagating e- and o-polarized optical modes. At lambda = 1.319 pm and lambda = 1.55 mu m the spectral bandwidths (FWHM) were 1.54 and 2.3 nm, respectively. A relative conversion efficiency of 43%/W and a maximum conversion efficiency of 51% were measured at 1.319 pm. (C) 2000 Optical Society of America OCIS codes: 120.2440, 230.0230, 230.1040, 260.0260, 260.1180, 260.5430.