Performance Of Individual Devices Research Articles

Lubrication of Microelectromechanical Systems (MEMS) Using Bound and Mobile Phases of Fomblin Zdol

A lubrication scheme for MEMS electrostatic lateral output motors based on a mixture of bound and mobile lubricant was studied. Lubrication by bound monolayer alone provided some increase in operational life, but after a short time, the film wore away and the device failed in the unlubricated mode. A mobile phase was used to provide lubricant replenishment. Tribological studies were conducted on Si(100) wafers, as well as on MEMS electrostatic lateral output motors, dip-coated with a mixture of bound and mobile phases of Fomblin Zdol. Accelerated screening tests on Si(100) wafers were undertaken using a pin on disk tribometer. However, the optimum balance of bound and mobile phases was determined by studies on the device itself. The fractional surface coverage of lubricant and the ratio of bound to mobile phase was varied through selection of reaction temperature and rinse chemistry. The mobile phase on model surfaces and devices acted as a source of lubricant replenishment, and together with the bound phase provided dramatic improvement in performance. The wide variation seen in the performance of individual devices suggests that dip coating does not provide a uniform coating on the contacting surfaces of these devices.

High-performance, high-isolation optical guided-wave device arrays

Dense arrays of high-performance photonic devices could provide many advantages to photonic systems in terms of system performance and cost. However, many problems exist. These include individual device performance, device-to-device crosstalk, packaging, and cost. To investigate these issues, arrays of traveling-wave electrooptic modulators based on LiNbO/sub 3/ (lithium niobate) have-been designed, implemented, and evaluated. Four-element arrays of 20-GHz modulators have been demonstrated for the first time with modulator-to-modulator crosstalk of less than -50 dB even though the modulator die reside on the same substrate and are separated by only 1.5 mm. The approach developed is extendable to arrays containing up to 100 elements.

Design, modeling, and characterization of monolithically integrated InP-based (1.55 μm) high-speed (24 Gb/s) p-i-n/HBT front-end photoreceivers

High-speed, long-wavelength InAlAs/InGaAs OEIC photoreceivers based on a p-i-n/HBT shared layer integration scheme have been designed, fabricated and characterized. The p-i-n photodiodes, formed with the 6000 /spl Aring/-thick InGaAs precollector layer of the HBT as the absorbing layer, exhibited a responsivity of /spl sim/0.4 A/W and a -3 dB optical bandwidth larger than 20 GHz at /spl lambda/=1.55 /spl mu/m. The fabricated three-stage transimpedance amplifier with a feedback resistor of 550 /spl Omega/ demonstrated a transimpedance gain of 46 dB/spl Omega/ and a -3 dB bandwidth of 20 GHz. The monolithically integrated photoreceiver with a 83 /spl mu/m p-i-n photodiode consumed a small dc power of 35 mW and demonstrated a measured -3 dB optical bandwidth of 19.5 GHz, which is the highest reported to date for an InAlAs/InGaAs integrated front-end photoreceiver. The OEIC photoreceiver also has a measured input optical dynamic range of 20 dB. The performance of individual devices and integrated circuits was also investigated through detailed CAD-based analysis and characterization. Transient simulations, based on a HSPICE circuit model and previous measurements of eye diagrams for a NRZ 2/sup 31/-1 pseudorandom binary sequence (PRBS), show that the OEIC photoreceiver is capable of operation up to 24 Gb/s.

Integrated inversion channel optoelectronic devices and circuit elements for multifunctional array applications

An approach to laser-based optoelectronic integration is described. It is shown that by using a single epitaxial growth structure and a common processing sequence, all the electrical and optical devices required for a complete optoelectronic integrated circuit (OEIC) are realized. The demonstrated individual device performance and the implementation of an integrated combination of devices are discussed. Such applications as the implementation of a basic building block for a 2*2 smart-pixel switching node are discussed. A comparison to other laser- and modulator-based approaches is presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>