John V. Gates

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.

Dynamic wavelength equalizer in silica using the single-filtered-arm interferometer

A dynamic wavelength equalizer that can control attenuation at 22 points across 35 nm of spectrum in a smooth manner is presented. It achieves low loss (4.7 dB), because it consists of a Mach-Zehnder interferometer with a wavelength-dependent element in only one arm. Additional development is needed to reduce the polarization sensitivity.

40-wavelength add drop filter

We present in 40-wavelength, 100-GHz channel spacing, programmable, planar add-drop filter that has flattened passbands without excess loss. For TE polarized light, the insertion loss is 9-11 dB for the through channels, and the dropping extinction ratio is /spl ges/33 dB.

Arrayed waveguide lens wavelength add-drop in silica

We present experimental results of an integrated 16-channel, 100-GHz-channel-spacing wavelength add-drop in silica. It consists of two interleave-chirped waveguide grating routers connected by an array of waveguides containing thermooptic phase shifters. The fully packaged device has 6.6-7.6-dB fiber-to-fiber insertion loss and a switching extinction ratio >27 dB (>33 dB for a single polarization) when used as an add-drop, It is compact, allowing for at least four such devices per 5-in-diameter wafer.

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.

Compact 64 x 64 micromechanical optical cross connect

Describes a 64 x 64 beam steering optical cross connect constructed using surface micromachined mirrors. It used a curved mirror as a Fourier transform element and to fold the optical system. Both micromechanical switches mirror arrays are fabricated on a single chip and packaged in a single package. The switch fabric size, at 100×120×20 mm, is compatible with mounting on a standard circuit card. The cross connect achieves a mean fiber-to-fiber insertion loss of 1.9 dB.

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.

Smart dynamic wavelength equalizer based on an integrated planar optical circuit for use in the 1550-nm region

A microprocessor-controlled dynamic wavelength equalizer is presented. Th subsystem is based on an integrated optical circuit made in silica and covers a large portion of the usable region of the electromagnetic spectrum for optical fiber transmission (1530-1565 nm). The chip is connected in a software-controlled feedback loop, and with its dynamic range of /spl sim/7 dB for each channel, the system is capable of flattening the spectral response of an erbium-doped fiber amplifier to within 0.35-dB peak-to-peak. Insertion loss equals /spl sim/8 dB.

Photonic packaging using laser/receiver arrays and flexible optical circuits

Optoelectronic modules and multifiber optical connectors were successfully applied to intrasystem interconnection within a large telecommunication transmission terminal. The optoelectronic modules are 32-channel 850 nm vertical cavity surface emitting laser (VCSEL) and detector arrays packaged using multichip module technology system components include multimode silica optical fibers and silicon V-groove technology based multifiber optical connectors. The system architecture presented particularly difficult challenges for parallel optics because of complex cable assemblies required by the fan-out nature of the cables and the signal bifurcation needed to accomplish duplication, Nevertheless, the experiments completed demonstrate that parallel optics can dramatically increase the capacity of telecommunications equipment with no significant changes in system or physical architecture. The density of the optical modules and connectors clearly demonstrates that optical interconnection technology will be able to support the input/output (I/O) requirements of new generations of integrated circuit technology.