Arman Gasparyan

1100 x 1100 port MEMS-based optical crossconnect with 4-dB maximum loss

We present a microelectromechanical systems-based beam steering optical crossconnect switch core with port count exceeding 1100, featuring mean fiber-to-fiber insertion loss of 2.1 dB and maximum insertion loss of 4.0 dB across all possible connections. The challenge of efficient measurement and optimization of all possible connections was met by an automated testing facility. The resulting connections feature optical loss stability of better than 0.2 dB over days, without any feedback control under normal laboratory conditions.

Beam-steering micromirrors for large optical cross-connects

This paper describes Si-micromachined two-axis beam-steering micromirrors and their performance in 256 /spl times/ 256- and 1024 /spl times/ 1024-port large optical cross-connects (OXCs). The high-reflectivity wavelength-independent mirrors are electrostatically actuated; capable of large, continuous, controlled, dc tilt in any direction at moderate actuation voltages; and allow setting times of a few milliseconds. Packaged two-dimensional (2-D) arrays containing independently addressable identical 256 and 1296 mirrors are used to build fully functional bitrate and wavelength-independent single-stage, low-insertion-loss, single-mode fiber OXC fabrics.

Effects of electrical leakage currents on MEMS reliability and performance

Electrostatically driven MEMS devices commonly operate with electric fields as high at 10/sup 8/ V/m applied across the dielectric between electrodes. Even with the best mechanical design, the electrical design of these devices has a large impact both on performance (e.g., speed and stability) and on reliability (e.g., corrosion and dielectric or gas breakdown). In this paper, we discuss the reliability and performance implications of leakage currents in the bulk and on the surface of the dielectric insulating the drive (or sense) electrodes from one another. Anodic oxidation of poly-silicon electrodes can occur very rapidly in samples that are not hermetically packaged. The accelerating factors are presented along with an efficient early-warning scheme. The relationship between leakage currents and the accumulation of quasistatic charge in dielectrics are discussed, along with several techniques to mitigate charging and the associated drift in electrostatically actuated or sensed MEMS devices. Two key parameters are shown to be the electrode geometry and the conductivity of the dielectric. Electrical breakdown in submicron gaps is presented as a function of packaging gas and electrode spacing. We discuss the tradeoffs involved in choosing gap geometries and dielectric properties that balance performance and reliability.

1296-port MEMS transparent optical crossconnect with 2.07 petabit/s switch capacity

A 1296-port MEMS transparent optical crossconnect with 5.1dB/spl plusmn/1.1dB insertion loss at 1550 nm is reported. Measured worst-case optical crosstalk in a fabric was n38 dB and nominal switching rise/fall times were 5 ms. A 2.07 petabit/s switch capacity was verified upon cross-connecting a forty-channel by 40 Gb/s DWDM data stream through a prototype fabric.

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.

256/spl times/256 port optical cross-connect subsystem

This paper describes the subsystem design and performance of a 256/spl times/256-port micromechanical beam-steering optical cross-connect with 1.33-dB average loss, which can provide 238/spl times/238-port cross-connect with a maximum loss of less than 2dB. This paper describes the design chosen and analyzes the tolerance ranges required to produce low loss and simulate the expected loss distribution of the fabric. The method of establishing and testing the connections is also described. The simulation is compared with the measured system, and the expected and measured static and dynamic crosstalk are compared.

High-dynamic range channelized MEMS equalizing filter

We have demonstrated a channelized micro-mechanical filter with 5 dB insertion loss and high extinction suitable for use as a channelized equalizing filter. The pass bands have been demonstrated to be sufficiently wide to permit its use with 40 Gb/s CSRZ signals.

Anodic oxidation and reliability of MEMS polysilicon electrodes at high relative humidity and high voltages

We present a full factorial study of the effect of relative humidity and voltage on the oxidation of surface-micromachined poly-silicon wiring and electrodes. Our system consists of 500 nm thick poly-Si wires and electrodes insulated from the substrate wafer by 600 nm of Si-rch SixNy, fabricated using a surface-micromachinging process. In dry ambients, oxidation or damage to the bottom poly-Si layer (the Poly0 layer) in MicroElectroMechanical Systems (MEMS) devices occurs so slowly that little can be learned in a timely manner, even when stressing the electrodes at electric fields close to dielectric breakdown. We observe however that in ambient with elevated relative humidity the Poly0 wires and electrodes anodically oxidize within a short period of time when operated at moderately large voltages. Only the most positively biased poly-Si structures oxidize, and we describe the anodic oxidation and association volume expansion as a function of a number of accelerating factors including relative humidity and voltage. A threshold is observed in relative humidity bot not in voltage.

238/spl times/238 surface micromachined optical crossconnect with 2dB maximum loss

A fully provisioned 238/spl times/238 beam-steering optical crossconnect constructed using surface micromachined mirrors is described. The mean fiber-to-fiber insertion loss of the fabric is 1.33dB and the maximum insertion loss is 2dB.

Electro-optic effect in an unbalanced AlGaAs/GaAs microresonator

An unbalanced Fabry–Perot resonator is proposed as a miniature electro-optic probe. The resonator allows simultaneous enhancement of the electro-optic effect and the total reflectance at the resonance wavelength. We demonstrate a compact 3.31μm long electro-optic probe based on the unbalanced AlGaAs∕GaAs microresonator.