Fabio Jutzi

Spectral phase, amplitude, and spatial modulation from ultraviolet to infrared with a reflective MEMS pulse shaper

We describe the performance of a reflective pulse-shaper based on a Micro-ElectroMechanical System (MEMS) linear mirror array. It represents a substantial upgrade of a preceding release [Opt. Lett. 35, 3102 (2010)] as it allows simultaneous piston and tilt mirror motion, allowing both phase- and binary amplitude-shaping with no wavelength restriction. Moreover, we show how the combination of in-axis and tilt movement can be used for active correction of spatial chirp.

Design, simulation, fabrication, packaging, and characterization of a MEMS-based mirror array for femtosecond pulse-shaping in phase and amplitude

We present an in-detail description of the design, simulation, fabrication, and packaging of a linear micromirror array specifically designed for temporal pulse shaping of ultrashort laser pulses. The innovative features of this device include a novel comb-drive actuator allowing both piston and tilt motion for phase- and amplitude-shaping, and an X-shaped laterally reinforced spring preventing lateral snap-in while providing high flexibility for both degrees of freedom.

High aspect ratio micromirror array with two degrees of freedom for femtosecond pulse shaping

We show the first results of a linear 100-micromirror array capable of modulating the phase and amplitude of the spectral components of femtosecond lasers. Using MEMS-based reflective systems has the advantage of utilizing coatings tailored to the laser wavelength range. The innovative features of our device include a novel rotational, vertical comb-drive actuator and an X-shaped, laterally reinforced spring that prevents lateral snap-in while providing flexibility in the two degrees of freedom of each mirror, namely piston and tilt. The packaging utilizes high-density fine-pitch wire-bonding for on-chip and chip-to-PCB connectivity. For the first deployment, UV-shaped pulses will be produced to coherently control the dynamics of biomolecules.

A dual-axis high fill-factor micromirror array for high thermal loads

A high fill-factor, dual-axis micromirror array with novel spring and actuator design is developed for high thermal load applications. Each pixel can attain an omnidirectional mechanical DC rotation angle of ±4 degrees.

Fabrication and characterization of 3D integrated 2 DOF Micromirror Arrays for excessive thermal loads

This paper reports a high fill-factor (>90%), 2-dimensional analog micromirror array designed specifically for very high, optically induced thermal load applications. Each pixel can attain a mechanical DC rotation angle of ±4 degrees around any arbitrary axis with 170V excitation. The maximum temperature rise on the mirror surface with 7 KW/m2 thermal load under 1 Pa ambient pressure is below 230 °C. A detailed assessment of the fabrication process - including the poly-Si vertical electrodes, wafer level mirror bonding, and copper electroplating of structural layers-, and characterization methodology is presented with experimental results.

Vertical electrostatically 90° turning flaps for reflective MEMS display

A new kind of MEMS reflective display is being developed having high contrast and reflectivity, better than on printed paper. The system is based on novel vertical flaps, which can be electrostatically turned by 90° to horizontal position. After fabrication, the poly-silicon flaps are vertical to the wafer surface and on the top suspended by torsion beams. In this state the pixel is black, incoming ambient light passes by the flaps and is absorbed by an underlying absorptive layer. When the flaps are turned to horizontal position light is reflected back and the pixel gets white. A self-aligning four masks bulk microfabrication process is employed, which uses poly-silicon filling of high aspect-ratio cavities. Parylene was also employed as flap material. Thanks to auto stress-compensation the flaps are not deformed due to intrinsic stresses. Low actuation voltages down to 20V can be achieved.

Low voltage electrostatic 90° turning flap for reflective MEMS display

A low voltage electrostatically actuated 90° turning flap is modeled and fabricated. The application is a new kind reflective, low-power, MEMS-based display with high contrast and reflectance. The system consists of a poly-silicon flap fabricated onto a silicon substrate with a transparent counter electrode on glass and a device layer of a silicon-on-insulator (SOI) wafer as spacer in between them. Actuation voltages down to 20V are achieved.

Low voltage vertical flaps arrays as optical modulating elements for reflective display and switchable gratings

A novel technology is presented for arrays of vertical flaps as optically modulating elements which are actuated electrostatically to horizontal position at low voltages of 30-50V. One application is a reflective display exhibiting a contrast ratio of 1:95. We will also show a) shutters for transmissive devices in an array configuration and b) switchable gratings. A large variety of flap geometries are fabricated such as flat reflective, grating, lens or grid shape. Poly-Si refill of thin high aspect-ratio trenches followed of dry etching of the surrounding material is used to fabricate the flaps suspended by torsion beams.

Electrostatic torsional vertical flaps for reflective MEMS display

A new kind of high contrast, MEMS-based reflective display system is being developed. The system consists of light reflective flaps on an optically absorptive surface. The novelty is that the flaps are in vertical position at their rest state. They can be electrostatically turned to horizontal state. A trench refilling technique on a silicon-on-insulator (SOI) wafer is used to fabricate the torsional polysilicon flaps. Low voltage and low power is required for actuation. With the same process also novel shutter and flap structures can be fabricated.

Vertical flaps of arbitrary shape for reflective MEMS displays and optical modulators

A novel technological platform is presented for the fabrication of vertical flaps and gratings of arbitrary shape. The flaps are suspended by torsion beams and actuated electrostatically at voltages as low as 10V. The main application is a high contrast reflective display.