PLZT electrooptic ceramic photonic devices for surface-normal operation in trenches cut across arrays of optical fiber

Simple Pb_1-xLa_x(Zr_yTi_z)_1-x4/O₃ (PLZT) electrooptic ceramic photonic device arrays for surface-normal operation have been developed for application to polarization-controller arrays and Fabry-Pe´rot tunable filter arrays. These arrays are inserted in trenches cut across fiber arrays. Each element of the arrayed structure corresponds to one optical beam and takes the form of a cell. Each sidewall of the cell (width: 50-80 μm) is coated to form an electrode. The arrays have 16 elements at a pitch of 250 μm. The phase modulator has about 1 dB of loss and a half-wavelength voltage of 120 V. A cascade of two PLZT phase modulators (thickness: 300 μm), with each attached to a polyimide λ/2 plate (thickness: 15 μm), is capable of converting an arbitrary polarization to the transverse-electric (TE) or transverse-magnetic (TM) polarization. The response time is 1 μs. The Fabry-Pe´rot tunable filters have a thickness of 50 μm. The front and back surfaces of each cell are coated by 99%-reflective mirror. The free spectral range (FSR) of the filters is about 10 nm, tunable range is about 10 nm, loss is 2.2 dB, and finesse is 150. The tuning speed of these devices is high, taking only 1 μs.