than 40-ms response time, using an 8 V drive. A novel structure with circularly
symmetric features, shown in Figure 19.27, was used to suppress polarization-
dependent loss to under 0.2 dB [130]. This device was one of the first Telcordia-
qualified MEMS components, with 40,000 units reportedly shipped by 2005 [164].
19.6 EMERGING MEMS TECHNOLOGIES
AND APPLICATIONS
19.6.1 MEMS-Tunable Microdisk/Microring Resonators
Microdisk or microring resonators offer another order of magnitude size reduction
for a wide range of WDM functions, such as add–drop multiplexers [165], dispersion
compensators [166], modulators [167], and WDM lasers [168]. Semiconductor
microresonators with high-index contrast can further reduce the resonator dimen-
sions, producing wide ...