Studyon The Driving Circuit, Packaging And Testing For PLZT Electro-optic Switch

The optical switch as OADM and OXC core devicehas wide applications in optical fiber communication. Lanthanum-doped lead zirconate titanate (PLZT) is a new transparent ferroelectric thin film material which has superior electro-optical properties.The PLZT waveguide electro-optic switches is characterized by small size, low driving voltage, short switching time (ns level) and easy to be integrated. It plays a positive role in the development ofoptical network, which attracted researchers’ widespread attention in recent years.By analyzing the working mechanism of 1 x 16 Mach-Zehnder interferometer-type (MZI) PLZT optical switch, a control and driving system is designed and produced, which is based on CPLD and MCU. Driving circuit based onpin driverEL7156 is designed to fit the capacitance characteristics of the different structures PLZT electro-optical switches. After debugging, the value of output voltage is 0-15V. When the load is 30pF capacitance value, the drive signal response time is about 7ns; when the load is 400pF capacitance value, the drive signal response time is about 19ns, which meets the needs of PLZT optical switch driver. Then, according to the MZI-type PLZT optical switch which made in our Iaboratory,wire bonded shell for electrode and metal packaging boxes with fiberare designed, using wire bonding to complete the chip and the PCB interconnection, and packaging technology to ensure thatthe PLZT optical switch can work effectively.Finally, a correspondinglight path and circuit is build for testing, and using the designed circuit to testthe performance of 1×2 MZI-type PLZT optical switches which made in our laboratory. After the test to obtain the bias voltage of the device is within 15 V, the response time of the circuit is within 10ns, the response time of the optical switch is about 25ns. The result of experiments show that the response timeof the circuit is less than 20ns, which meet therequirements for PLZT electro-opticalswitching speed as ns level, and the circuit can be used to drive to PLZT electro-optical switch work effectively.