Digitally controlled programmable high‐speed variable optical attenuator

Abstract

A digital closed‐loop controlled variable optical attenuator (VOA) module using an FPGA (Field Programmable Gate Array) chip for optical‐power‐fluctuation suppression is demonstrated in this paper. A VOA based on transparent electro‐optical ceramic, OptoCeramic® PLZT, is used to provide high‐speed optical power control. With logarithm amplifiers and A‐D‐A feedback circuitry, this VOA module could be designed to operate as either an attenuator or a power controller. The module can be used to filter out the optical power fluctuation up to 300 kHz. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1019–1021, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21588

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