MEMS-Tuned Microresonators

  • Ming-Chang M. Lee
  • Ming C. Wu
  • David Leuenberger
Part of the Springer Series in Optical Sciences book series (SSOS, volume 156)


Micro-electro-mechanical systems (MEMS) is a key enabling technology to realize scalable and reconfigurable optical components. Since Peterson (1982) demonstrated the first MEMS scanning mirror, many free-space optical MEMS including digital micromirror devices (DMD), micromirror switches, and optical scanners have been accomplished. In guided-wave optics, MEMS have demonstrated the ability for controlling evanescent and butt coupling between waveguides. This chapter investigates the integration of MEMS actuators with optical microresonators and introduces a new family of tunable photonic devices.

Most tunable microresonators rely on electro-optics, thermo-optics, free-carrier dispersion or gain/loss control to vary the index of refraction, which can be classified as “material modulation.” For MEMS-tuned microresonators, however, tunability comes from the structure or the configuration of microresonators modified by mechanical actuation, which is termed as “configuration modulation.” Using MEMS to alter the configuration of microresonators has various advantages. First, the functionality of photonic devices based on the resonators is adjustable or tunable. Second, unintentional variation of spacing between components after fabrication may be ameliorated by fine-tuning the configuration.

The content of this chapter is organized as follows. Section 1 introduces control factors to implement tunable microresonators and the model of corresponding optical transfer functions. A summary of the state-of-the-art tuning mechanisms is also given. Section 2 demonstrates MEMS variable couplers for tunable microdisk resonators. Several functions, including tunable coupling regimes, tunable slow light, dynamic add-drop filters, and dynamic bandwidth (BW) allocation, are presented. Section 3 shows that the quality factor of microresonators can be reduced by attaching an absorber through MEMS actuators. A wavelength switch is demonstrated. Section 4 gives an example of that the resonant wavelength tuned through varying the cavity length of microresonators. Based on this idea, tunable filters and lasers are accomplished by incorporating MEMS actuators.


Amplify Spontaneous Emission Resonant Wavelength Distribute Bragg Reflector Coupling Ratio Optical Transfer Function 



The authors would like to acknowledge Prof. A. Uskov from the P.N. Lebedev Physical Institute, Moscow, for helpful discussions and the support of DARPA for the work on tunable slow light. Furthermore they would like to acknowledge the contribution by Dr. B. Zhang and Prof. A.E. Willner from USC in the experiment of bandwidth-tunable filters.


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Copyright information

© Springer-Verlag US 2010

Authors and Affiliations

  • Ming-Chang M. Lee
    • 1
  • Ming C. Wu
    • 2
  • David Leuenberger
    • 3
  1. 1.Department of Electrical Engineering and Institute of Photonics TechnologiesNational Tsing Hua UniversityHsinChuTaiwan
  2. 2.Department of Electrical Engineering & Computer SciencesUniversity of CaliforniaBerkeleyUSA
  3. 3.CSEM Centre Suisse d’Electronique et de Microtechnique SAZürichSwitzerland

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