Foster-Miller is developing a family of low cost active WDM components based on electronically switchable Bragg gratings (ESBG) in holographically polymerized polymer dispersed liquid crystal. These provide approximately 50 microsecond(s) switching speeds, adequate for many network reconfiguration functions.Space switches, wavelength selective add-drop multiplexers, attenuators and switchable taps may be integrated in a variety of architectures on chip by using ESBGs with different periods and device geometries. ESBG fabrication is a one step, low cost process compatible with standard silicon optical waveguide techniques.
Electronically switchable Bragg gratings (ESBG) based on holographic polymerized polymer/liquid crystal composites have been described by Sutherland et al. We present an overview of potential applications to waveguide based fiber optic NXN crossconnect and waveguide selective (WDM) crossconnect devices. Various proposed waveguide grating devices are described, and silicon and glass/polymer fabrication paths are outlined. Recent experimental results are summarized. ESBGs are a promising new technology for efficient, large N scalable, moderate speed reconfigurration switches for fiber optic networks.
We describe the design of single frequency array transmitters and their application in RF-photonic systems. In addition, we present an array-based packaging technology that is based on passive-alignment with Si-waferboards.
Silicon waferboard technology based on etched and deposited passive-alignment features has been applied to the fabrication of optoelectronic transmitter and receiver arrays for rf applications. Using silicon waferboards, we have aligned both 1 by 4 buried-heterostructure laser arrays and 1 by 4 PIN photodetector arrays to optical fiber ribbons. Besides serving as mechanical carriers and alignment guides, the silicon wafers can also be used as rf or microwave substrates. We introduce rf-optoelectronic receiver arrays based on such enhanced silicon waferboards.
This paper describes the development of laser transmitter arrays for analog optoelectronic link applications up to 2 GHz. These modules have been developed in an attempt to utilize passive assembly and alignment operations for the purpose of reducing costs. To this end, silicon waferboard integration platforms and semiconductor laser arrays have been fabricated with special alignment features that allow passive assembly of flip-chip laser arrays to single-mode optical fiber arrays.
We describe the design, fabrication, and testing of a silicon waferboard dual-detector module used in an integrated optical heterodyne balanced receiver. This 'Silicon Waferboard' approach, as its name implies, substitutes a silicon substrate incorporating precision micromachined structures in lieu of conventional printed circuit boards and has been used for both optical transmitter and receiver fabrication. Our dual-detector receiver substrate incorporates orientation-dependent etched v-grooves for fiber placement in addition to metal/insulator/metal (MIM) bypass capacitors and high-speed photodetectors. Preliminary measurements indicated a receiver bandwidth potential of 14 GHz. The performance of the dual-detector receiver module as well as its individual components will be described.
We have demonstrated the fabrication of two structures achieved by the thin ifim transfer technique: back4lluminated InAlAsfInGaAs metal. semiconducthr-metal (MSM) detectors with buried interdigitated fingers on GaAs substrates; and long wavelength InGaAsP lasers on GaAs or Si substrates. For optoelectromc system applications, one often considers the use of a single material system for both the optical and electronic components on the chip, because it is not complicated by lattice mismatch. Compared to epitaxial growth of latticemismatched material systems, such as GaAs on Si, the thin ifim transfer technique does not result in a substantial number of misfit dislocations which can adversely affect device performance. The results we obtained demonstrate the feasibility of the thin film transfer process and point to the potential integration of OEICs and other components fabricated from a variety of materials on a common host substrate.
Although optoelectronic components are used widely in the telecommunications industry, this technology has barely touched
the potential of what could be vast markets in broadband local loop and computer interconnection applications. The reliability,
performance and particularly the cost of optoelectronic components must be improved for these applications to develop. Issues
involving component packaging to a large extent determine the level to which these application criteria are met.1 This paper
explores advances in semiconductor laser packaging that are aimed at reaching levels of component integration required for
extensive use of optoelectronics in computer and communications systems applications.