Variable optical attenuator using a thermal actuator array with dual shutters

Abstract

A compact variable optical attenuator (VOA) driving by thermal actuating principle with dual shutters for single mode fibers is developed. The fabricated thermal actuator array is capable of achieving larger displacement with low applied voltage than traditional thermal actuator array. The designed dual shutters can be driven independently or simultaneously, which increase the accurate tuning range and decrease working voltage for variable optical attenuator. The device is fabricated using MEMS-SOI fabrication technology, which greatly simplifies the traditional surface micromachining technology and increases its corresponding reliability. The newly designed thermal actuator array is capable of traveling 20 Pm distance with less than 5 V applied voltage for VOA application. The insertion loss of the fabricated VOA is below 1.5 dB. The initial return loss and working return loss is about 50 and 40 dB, respectively. Experimental results indicated that the response time is below 4 ms and maximum attenuation range is about 40 and 45 dB at 1550 and 1310 nm, respectively. The working voltage and temperature of the designed VOA is under 5 V and 550 K, respectively. (C) 2004 Elsevier B.V. All rights reserved.