A silicon MEMS optical switch attenuator and its use in lightwave subsystems

A single-mode fiber connectorized microelectromechanical systems (MEMS) ref lective optical switch attenuator operating in the 1550-nm wavelength regio n is described. The device consists of an electrostatically actuated gold-c oated silicon vane interposed in a fiber gap yielding 0.81-dB minimum inser tion loss in the transmit state and high transmission isolation in the refl ection state with 2.15-dB minimum return loss. The switch attenuators also work as continuously variable optical attenuators capable of greater than 5 0-dB dynamic range and can be accurately regulated with a simple feedback c ontrol circuit. Switching voltages mere in the range of 5-40 V and a switch ing time of 64 mu s was achieved. The MEMS switch can be used in optical subsystems within a wavelength-divis ion-multiplexed (WDM) optical network such as optical power regulators, cro ssconnects, and add/drop multiplexers, We used a discrete array of 16 switc h attenuators to implement a reconfigurable 16-channel 100-GHz spacing WDM drop module of an add/drop multiplexer, Thru-channel extinction was greater than 40 dB and average insertion loss was 21 dB, Both drop-and-transmit of multiple channels (11-18-dB contrast, 14-19-dB insertion loss) and drop-an d-detect of single channels (>20-dB adjacent channel rejection, 10-14-dB in sertion loss) were demonstrated.