Gregory A. Kirkos

Electromagnetically actuated mirror arrays for use in 3-D optical switching applications

This paper presents an electromagnetic MEMS mirror technology for use in 3-D optical switching applications. These mirrors may be actuated through large angles at low voltage and low current. Multiple coils on the backs of the mirrors interact with permanent magnetic fields to provide two-axis orthogonal actuation. A custom package brings the MEMS mirror array and magnets into close proximity. Actuation is linear versus drive current on both axes, and displays negligible charging and drift. These mirrors have achieved greater than 10/spl deg/ mechanical rotation per mA in each axis. The mirror rotation angle is hysteresis free to less than the 0.01/spl deg/ measurement accuracy.

MEMS tilt-mirror spatial light modulator for a dynamic spectral equalizer

This paper presents a linear array of tilting mirrors used to attenuate the various wavelengths in a DWDM optical signal. Attenuation of 21 dB at snap-down was achieved by the tilting mirrors, substituting for a liquid crystal spatial light modulator (SLM) in a commercial dynamic spectral equalizer (DSE). Linear fill factor of 92% was achieved, allowing closely spaced wavelength channels to be individually attenuated. A two layer polysilicon process with a thick epi-poly mirror was used to fabricate the SLM. Initial mirrors had a radius of curvature of 25 cm. A novel accelerated HF-H/sub 2/SO/sub 4/ etch allowed 100 /spl mu/m wide mirrors to be undercut in 12 min with no etch release holes.

A high fill factor linear mirror array for a wavelength selective switch

Optical networks require optical switching systems with high linear fill factor mirror arrays for wavelength add/drop nodes. The mirrors presented here use coils attached to the mirrors interacting with the field from a permanent magnet array. Results of magnetic and mechanical FEA modeling are presented. Fill factors in excess of 90% were achieved, and mirror rotation in excess of 5° (mechanical angle) with less than 10 mA current was demonstrated. Mirrors operated in excess of 2.8 billion cycles with no fatigue or failures.

Electrostatic micromirror arrays fabricated with bulk and surface micromachining techniques

High-density micromirror arrays have been fabricated with a process that combines the benefits of both bulk and surface micromachining. Arrays fabricated with this technique are characterized by flat mirrors, high spring constant uniformity, and high yield. Each pixel consists of a mirror-in-gimbal structure that allows the mirror to rotate about two orthogonal axes when a bias is placed on electrodes residing beneath the mirror. A new dry release process is introduced as a simple, effective alternative to critical point drying for releasing the structures.

Two axis-of-rotation mirror array using electromagnetic MEMS

This paper presents an overview of Coming IntelliSenses 3D electromagnetic MEMS mirror technology for use in optical switching applications. This work presents for the first time a dense array of mirrors actuated through large angles at low voltage and low current. Multiple coils on the backs of the mirrors interact with permanent magnetic fields to provide actuation. Unlike previous electromagnetic 2-axis mirrors, a novel and simple arrangement of coils and magnets provides true 2-axis orthogonal actuation, as well as an order of magnitude increase in tilt (/spl deg//mA). Actuation is linear vs. drive current on both axes, and displays negligible charging and drift. These mirrors have achieved greater than 10 degrees mechanical rotation per mA in each axis, a 40x increase over previously reported work. The mirror rotation angle is hysteresis free to less than 0.01 degrees, and is actuated at about 1 volt.

A high fill factor 1 /spl times/ N spatial light modulator based on an epitaxial polysilicon process

This study introduces novel spatial light modulator (SLM) designs with flat micromirrors which require no etch release holes. A combination of surface micromachining and epitaxial polysilicon process is used in device fabrication. This process minimizes insertion loss since it is based on the requirements of MEMS based optical systems.

Integration possibilities with MOEMS/MEMS devices and packaging technologies using a MEMS simulation tool

This paper reports on monolithic integration possibilities between a novel micromachined packaging technology and MEMS/MOEMS devices. A high-density lead connection scheme is tailored to fulfill the needs of emerging high density optoelectromechanical/microelectromechanical devices. The packaging structure employs double polysilicon as device and package fabrication and anodic bonding as the sealing technology. Thermal stresses arising due to sealing temperatures have been investigated for various device dimensions. The advantages of the micromachined lead transfer and packaging scheme has been explored and it is indicated that it can incorporate both surface and also bulk micromachined devices as post or intermediate processing steps.