This PDF file contains the front matter associated with SPIE Proceedings Volume 10295, including the Title Page, Copyright information, Table of Contents, and Conference Committee listing.

This paper reviews recent advancements in the area of mechanical reliability of optical fiber, building upon previously published reviews in this area.^1-5 Of particular significance is progress in the area of establishing reliability programs. This review considers efforts made to reduce early failures and to establish reliability programs with an emphasis on functional reliability.

The reliability of a fluoride fiber module generally depends on three factors. They are the lifetime of the fluoride fiber under practical environmental conditions, the reliability of the splice between fluoride and silica fiber in terms of low-loss and low-reflection, and the effectiveness with which the packaging prevents moisture damage. The first factor depends strongly on the fluoride fiber strength. We describe a technique for fabricating fluoride fiber with improved strength and then estimate its lifetime using a static fatigue test. We evaluate the remaining two factors by applying the recommended reliability test program to the fiber modules. We describe the structure of our fluoride fiber module and present the reliability test results with reference to the Bellcore Technical Advisory TA-NWT-001221.

This paper reviews the applicability of the mastercurve method for analyzing diverse reliability issues in fiber optics. Approaches to assess and predict small changes in optical properties of fiber gratings caused by thermally induced decrease in refractive index modulation, are presented and compared. The process of thermal stabilization to obtain gratings with excellent stability is explained. It is shown that the mastercurve approach when suitably modified could be used to analyze other reliability problems such as hydrogen induced loss and radiation induced effects in fibers.

Lightguide technology is now considered to be mature. Indeed, improvements in all aspects of this technology over the years have been most impressive - multimode to singlemode fiber, electronic to optical amplification and the newest and perhaps the most important: the use of WDM and DWDM technologies. In spite of these striking advances, the very nature of the silica lightguide material poses reliability issues which have not yet been fully resolved or in some cases even confronted. These issues by and large have to do with the intrinsic brittle nature of the glass material. In order to assure reliable performance of these lightguide fibers in telecommunications service environments, coating and cabling technologies developed over the past two decades have evolved to give robust fiber optic cables, devices and components. In this presentation, we review key materials issues in the development and use of lightguide technology in telecommunications. Furthermore, we analyze current trends and discuss major materials reliability issues that need to be resolved for further developments in future applications of optical fibers, fiber optic cables and fiber-based components.

The understanding of fiber optic connector and splice reliability has progressed in several areas in recent years. Material properties, failure mechanisms, environmental conditions and design parameters critical to performance are generally well known and are being addressed in the technical literature and in standards. Still lacking however, are reliability models for measuring and predicting failure rates. Acceptance tests are frequently used to approve a product for service, but there are no standard life-stress models for predicting failure rates over time. This and related problems are under study by several industry organizations. These topics are addressed in this review.

Basic components and devices for optical fiber sensor and telecommunication networks should exhibit survival times of 20 to 40 years. Fiber gratings are important basic devices for such networks. This demands good thermal and mechanical reliability of the grating itself. However, as it will be shown in this paper, both reliability aspects depend strongly on factors like grating fabrication conditions, the fiber used, a possible photosensitization process, etc. The thermal stability of fiber gratings is strongly linked to the fiber, its co-dopants and possible photosensitization by hydrogen loading. Determining the electron distribution of the involved defects can assess the reliability. To a first approximation the decay is determined by the decay frequency v₀. Good thermal stability over 25 years at 40 °C can be predicted for germanosilicate fibers if the gratings are annealed for 110 hours at T≈120 °C. Higher operating temperatures demand higher annealing temperatures for reasonable annealing times and do need therefore special protections like polyimide coatings. The mechanical breaking strength of fiber gratings is related to the grating fabrication process and fiber preparation. For telecommunication applications, gratings are in general fabricated off-line. In this case, careful chemical fiber stripping and handling is needed. When gratings are written using pulsed KrF excimer laser irradiation a considerable mechanical degradation is observed, which depends on the irradiation conditions. In contrary, frequency doubled CW-Ar⁺ laser irradiation almost preserves the median breaking stress. Gratings fabricated by one single laser shot or written through the fiber coating show almost no degradation. However, due to their low reflectivity the use of single shot gratings is mostly restricted to sensor applications. The fabrication of grating devices by irradiation through the coating is still limited to index modulations of 10^-4 due to coating degradation.

The demands of global bandwidth and distribution are rising rapidly as Internet usage grows. This fundamentally means that more photons are flowing within optical cables. While transmitting sources launches some optical power, the majority of the optical power that is present within modem telecommunication systems originates from optical amplifiers. In addition, modem optical amplifiers offer flat optical gain over broad wavelength bands, thus making possible dense wavelength de-multiplexing (DWDM) systems. Optical amplifier performance, and by extension the performance of the laser pumps that drive them, is central to the future growth of both optical transmission and distribution systems.

In this article, the recent progress and the performance, applications and reliability for 1480nm and 980nm pump laser module with Fiber Bragg Grating (FBG) wavelength stabilized for EDFA pumping purpose are discussed.

Discovery Semiconductors has developed 50 GHz “Dual-depletion InGaAs/InP Photodiodes”. The PIN operates at -3V reverse bias and has minimum responsivity of 0.7 AAV at 1.3 and 1.55 um wavelength. The Ripple Factor is less than ±1 dB for a wide band of frequencies, DC to 50 GHz. The salient feature of the PIN is an on-chip coplanar waveguide output for proper impedance matching. The PIN exhibits group delay of less than ± 20 psec across the entire bandwidth. Discovery Semiconductors has also designed 50 GHz InGaAs PIN / p-HEMT Amplifier Photoreceiver Opto-electronic Integrated Circuit (OEIC) with a voltage conversion gain of 60 VAV at 1550 nm. The Photoreceiver OEIC exhibits an electric back reflection (S₂₂) of less than -10 dB across the entire 50 GHz bandwidth. The optical back reflection is better than -30 dB at 1300 and 1550 nm.

This paper is about the reliability of lithium niobate external modulators, one of the first major commercial successes for integrated optical circuits in fiber optics. Results from Bellcore type qualification programs along with long term aging tests at several temperatures for 2.5 Gb/s and 10 Gb/s modulator types will be presented., Additional published reliability data will be referenced and shown, however, limited information is available. Actual field data will also be presented. Where fitting or noteworthy, references will be made to other types of integrated optical circuits as this technology field is much greater than modulators alone. For the purposes of this paper, lasers, electro-absorption modulators, acousto-optic devices and optical detectors are not considered even though they too are highly commercially successful integrated photonic devices.

Micro-electro-mechanical-systems (MEMS), due to their unique ability to integrate electrical, mechanical, and optical elements on a single chip, have recently begun to exhibit great potential for realizing optical components and subsystems in compact, lowcost form. Recently, this technology has been applied to wavelength-division-multiplexed (WDM) networks, and resulted in advances in several network elements, including switches, filters, modulators, and wavelength-add/drop multiplexers. Due largely to the exploding capacity demand arising from data traffic, the transmission capacity demanded of and available from WDM networks is anticipated to increase rapidly. For managing such networks, optical switching is of particular interest due to the fact that its complexity is essentially immune to steady advances in the per-channel bit-rate. We will review various micromachined optical-switching technologies, emphasizing studies of their reliability. We then summarizing recent progress in the free-space MEMS optical switch we have demonstrated.

To match the bandwidth requirements of our fast-growing communication world, submarine networks have to provide ever greater transmission capacity. Thus, almost 2 Tbit/s will soon be the capacity available in submarine networks. A high level of availability is achieved owing to a very reliable submarine cable and to powerful network protection mechanisms.

Future higher-performance systems will be more complex than today's systems since the wavelength domain will be used to help route signals through different static or reconfigurable network paths. In these next-generation systems, several parameters may vary which would have deleterious effects in a WDM environment, including: variable insertion losses, channel addition and deletion (i.e., add/drop multiplexing), unstable laser power, non-uniform EDFA gain, non-uniform accumulation of dispersion and nonlinearities, and polarization mode dispersion that varies with fiber temperature. In order to ensure robust system operation, we discuss in this paper various dynamic schemes for compensating damaging effects so that these complex systems maintain high performance.

Fiber optic advances made in the 1980s have revolutionized the concept of telecommunications services and applications. With the development of integrated photonics and deployment of optical technology in many diverse applications, inroad of lightwave systems to traditionally captive arena of alternative technologies has been rather impressive. The 90’s trend to include technologies such as optical amplifiers, DWDM and gratings combined with a variety of new services such as internet, broadband network, and multimedia, can only make this inroad much deeper in the millennium. An ultimate goal, beyond the point-to-point/-multipoint transmission and distribution capability achieved thus far, is to provide a fault-tolerant, reliable connectivity in multi-user networks where the electrical bottlenecks will be avoided altogether by performing all functions, e.g., switching, mux/demux, etc., transparently in the optical domain. Technology for all-optical networking is still evolving with much development and engineering work remaining. These advanced networks based on WDM technology can only be realized to its fullest capability provided appropriate components are developed and tested, and the integrated systems meet specified performance goals. Therefore, the requirements for the production test facility and performance specifications of advanced DWDM networks have become increasingly complex and stringent. This paper reviews the critical requirements and production test issues relevant to DWDM components and networks. Impact of high-tech systems specifications on the quality of components and testability is also addressed.