David A. Ramsey

238 x 238 micromechanical optical cross connect

This letter describes a 238/spl times/238 beam-steering optical cross connect constructed using surface micromachined mirrors. Its innovative optical configuration resulted in superior optical performance, achieving a mean fiber-to-fiber insertion loss of 1.33 dB and a maximum insertion loss for all 56 644 connections of 2 dB.

Channel equalization and blocking filter utilizing microelectromechanical mirrors

This paper describes the design and performance of a 64-channel equalization and blocking filter. It utilizes a free space lens and grating multiplexer with micromechanical tilt mirrors providing variable attenuation. The module achieves a 5-dB insertion loss with a 3-dB passband of 87 GHz for 100-GHz spaced channels. The attenuation range achieved is in excess of 35 dB, making it suitable for wavelength blocking in switching applications. The device has been demonstrated to be compatible with 10- and 40-Gb/s transmission.

High-Density Solder Bump Interconnect for MEMS Hybrid Integration

An ultra high-density hybrid integration for micro-electromechanical system (MEMS) mirror chips with several thousand inputs/outputs has been developed. The integration scheme involving flip-chip assembly provides electrical signal to individual mirrors, which is compatible with postprocessing steps of selectively removing the silicon handle and releasing the MEMS mirrors. For the first time, to our knowledge, solder deposition and flip-chip bonding of 3-mum bumps on 5-mum centers of a large array has been demonstrated.

Optical MEMS devices for telecom systems

As telecom networks increase in complexity there is a need for systems capable of manage numerous optical signals. Many of the channel-manipulation functions can be done more effectively in the optical domain. MEMS devices are especially well suited for this functions since they can offer large number of degrees of freedom in a limited space, thus providing high levels of optical integration. We have designed, fabricated and tested optical MEMS devices at the core of Optical Cross Connects, WDM spectrum equalizers and Optical Add-Drop multiplexors based on different fabrication technologies such as polySi surface micromachining, single crystal SOI and combination of both. We show specific examples of these devices, discussing design trade-offs, fabrication requirements and optical performance in each case.

Challenges of packaging MEMS components for the all-optical networks of the future

Micro-optoelectromechanical systems (MOEMS) having valuable performance, size, and cost attributes offer novel solutions to the design of lightwave network elements. We will discuss the new challenges that realizing these benefits presents to the field of photonic packaging.

Packaging of optical MEMS devices

Recently, optical MEMS devices have gained considerable attention in the telecommunications industry -- particularly in the optical networking and switching arenas. Since optical MEMS are micro-systems which rely on high precision optics, electronics and mechanics working in close concert, these emerging devices pose some unique packaging challenges yet to be addressed by the general packaging industry. Optical MEMS packages often are required to provide both optical and electrical access, hermeticity, mechanical strength, dimensional stability and long-term reliability. Hermetic optical access necessitates the use of metallized and anti- reflection coated windows, and ever-increasing electrical I/O count has prompted the use of higher density substrate/package technologies. Taking these requirements into consideration, we explore three ceramic packaging technologies, namely High Temperature Co-fired Ceramic (HTCC), Low Temperature Co-fired Ceramic (LTCC) and thin-film ceramic technologies. In this paper, we describe some optical MEMS packages designed using these three technologies and discuss their substrate designs, package materials, ease of integration and assembly.

Closed-loop AO demonstration of MEMS SLM with piston, tip, and tilt control

A MEMS SLM with an array of 64×64 pixels, each 120 μm ×120 μm in size, with 98% fill-factor, has been developed. Each reflector in the array is capable of 5 μm of stroke, and ±4° tip and tilt. From a prototype array, 14 contiguous pixels have been independently wired-out to off-chip drive electronics. These 14 pixels have been demonstrated to be effective in an off-the-shelf AO system (with requisite modifications to suit the SLM). For a low-order static aberration, the measured Strehl ratio has been improved from 0.069 to 0.861, a factor of 12 improvement.