Jeffrey B. Sampsell

Digital flexure beam accelerometer

Acceleration is measured using an array of micro-machined elements. The array is configured so each successive element is deflected by a higher acceleration. For each acceleration there will be a set of elements that is deflected. By determining the transition point between deflected and undeflected elements, the acceleration can be measured.

Deformable mirror device spatial light modulators and their applicability to optical neural networks

All neural networks are characterized by a large number of interconnections between processor nodes. In general, the value of these interconnections (weights) must be modifiable. However, current semiconductor technology does not lend itself well to modifiable interconnection technology. A novel type of spatial light modulator, the deformable mirror device, is proposed as the breakthrough needed to solve the neural network interconnect problem.

Electro Optical Performance Of An Improved Deformable Mirror Device

The design, fabrication and performance of an improved 128 X 128 deformable mirror device (DMD) is presented. The DMD is a fast, low power, analog response, spatial light modulator. The improved DMD consists of a monolithically formed array of cantilever beams which are electrostatically deflected by an underlying MOS transistor address matrix. The on-chip address circuitry supports a single video input to the chip with all demux operations performed on-chip. The original DMD (1,2) differs in two respects from the improved version. Instead of monolithically formed cantilever beams, the original DMD utilizes a hybrid architecture wherein a continuous metalized membrane is placed over an underlying address chip by a mechanical lay-down process. In addition, instead of the single video input of the improved DMD, the original version has 128 inputs corresponding to the 128 columns of the x-y transistor matrix. The deformable mirrors of the improved DMD are cantilever beams formed by two layers of high reflectivity aluminum alloy. A thin layer forms the hinge and a thicker layer forms the cantilever beam and the surrounding support metal. The beam, hinge and support metalare formed over an underlying planarizing spacer layer, which is selectively removed by plasma etching to form an air gap underlying each cantilever beam pixel. This paper describes the design, fabrication and performance of the improved 128 X 128 cantilever beam DMD, including preliminary data on the Fourier plane behavior of this device and a discussion of its application to optical correlation. Dynamic range of the DMD in the Fourier plane at the Nyquist frequency has been measured at greater than 45 db and is limited by the CCD image detector used to record the intensity distribution.

Deformable mirror device uses in frequency excision and optical switching

A spatial light modulator is described which consists of a row of 1200 electrostatically deflectable mirror elements. This deformable mirror device is included in an acoustooptic spectrum analyzer and, as such, allows the removal of interfering signals from 333 frequency bands. Radiometric scans demonstrate the contrast and resolution possible with the device. Based on these results, the suitability of the device to frequency excisors and optical switches is considered.

Deformable mirror device based 4x4 fiber optic crossbar switch

The deformable mirror device (DMD) is a spatial light modulator . that offers both amplitude and phase modulation. The DMD is built on a silicon substrate and consists of small mirror elements (pixels) suspended above addressing electrodes via one or more small hinge. The pixels are deflected by electrostatic attraction created by applying a potential difference between the mirror element and addressing electrode.1 Both area array and linear DMDs have been built and been used in several areas.2-4