Sorry about all these posts, but I wanted to look at SDLI's work in fiber Bragg gratings, and got waylaid a few times.
From their website:
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SDL LAUNCHES NEW FIBER OPTIC PRODUCT LINE FOR DWDM MARKETSContact: SDL, Inc.
San Jose, California, February 3, 1998-- SDL, Inc. (Nasdaq National Market:SDLI). Rapid advances in optically-amplified, dense-wavelength division multiplexed (DWDM) transmission networks have fueled growing demand for a new class of fiber optic components. In response to this demand, SDL is launching a new line of fiber optic components based on the unique combination of benefits offered by fiber Bragg grating technology. Devices using fiber Bragg grating technology deliver cost-effective means of performing many functions required in DWDM systems. Because the devices are fabricated directly in the fiber, alignment and assembly cost can be significantly less than competing devices that use bulk optics and fiber.
This new family of products is based on technology which has been used in conjunction with semiconductor laser products from SDL for the past several years. Recently expanded engineering and production capacity in this area has allowed SDL to begin offering individual fiber Bragg grating components to OEM customers. According to Don Scifres, Chairman and CEO of SDL, “We have considerable experience producing fiber Bragg gratings for use with our 980 nm pump modules, so we have the manufacturing infrastructure and experience to support high volume production of these devices. Since these products are used in the same applications as our existing communications products, we already have strong technical and business relationships with key customers.”
The first products envisioned will support the development of the next generation of DWDM erbium-doped fiber amplifiers (EDFAs). A variety of fiber Bragg grating components are in various stages of development or evaluation, including noise suppression filters, gain flattening filters, dispersion compensating filters, add-drop multiplexing filters and 1550 nm reflectors. . . .>>>>
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The growing demand for bandwidth in all types of communication networks is causing an increase in the performance, quality and cost requirements of the equipment used to build these networks. The development of fiber optic amplifiers and the implementation of wavelength division multiplexing (WDM) are the primary innovations which have enabled fiber optic networks to expand quickly and economically to meet the bandwidth needs of increasing internet, data, video and voice traffic.
SDL offers a growing selection of innovative, high-performance products that are key elements in optically amplified, WDM networks as well as Broadband CATV networks. SDL combines world class development and manufacturing expertise in high power semiconductor lasers, fiber lasers, fiber amplifiers and fiber Bragg gratings, to create product solutions that enhance and advance the performance and value of fiber optic networks.
Fiber Amplifier Pumps
Erbium doped fiber amplifiers (EDFAs) exhibit superior noise figure performance when pumped by 980 nm laser. This means longer span distances can be designed between repeater amplifiers, which means fewer amplifiers are required for a given link distance, resulting in lower network cost. SDL started manufacturing single mode 980 nm lasers for pumping EDFAs in 1990. Since then, our pump lasers have been used by major telecommunications and CATV equipment manufacturers around the world. SDL has established a substantial reliability history at both the laser chip and fiber-coupled module level with millions of device hours of field deployed products.
SDL also pioneered the use of fiber Bragg gratings by developing a patented grating stabilized pump module. Grating stabilization delivers superior wavelength stability and enables precise wavelength specification. Both of these performance characteristics are increasingly important as channel density increases in EDFAs for WDM networks. Wavelength stability is also critical for demanding underseas deployment of 980 nm pumped EDFAs. All SDL standard pump modules feature fiber Bragg grating stabilization.
SDLO-2200 Series is a coolerless fiber Bragg grating stabilized pump module. Kink free output powers up to 80 mW are possible without the use of a thermoelectric cooler over a broad temperature range from 0-50 C. Over this temperature range high reliability and electro-optical performance are maintained. Eliminating the cooler reduces the total electrical power required by the pump module by as much as 2W. Grating stabilization maintains the pump module at a constant center wavelength independent of drive current and temperature over the specified range of operation.
SDLO-2400 Series features a streamlined optical design that results in improved manufacturing efficiency making this a our most economical pump module. Kink free optical powers up to 110 mW are available in this series. The SDLO-2400 Series features the same high reliability as other SDL pump modules and is supported by extensive qualification and lifetesting data. This pump module series offers an unmatched combination of price and performance.
SDLO-2500 Series of pump modules represents the latest evolution in high power pump modules from SDL. As the number of wavelengths being utilized in WDM networks increases, the pump power required to maintain EDFA performance also increases. With kink free optical power up to 165 mW, these modules are designed to meet the most demanding performance needs of a new generation of EDFAs. The SDLO-2500 Series features the SDL-6530 laser chip, the latest generation of high reliability semiconductor lasers from SDL.
SDLO-WM Series is a multiplexed pump source that combines the output of up to four pump modules to obtain over 500 mW of kink free power. This source uses low insertion loss wavelength combiners to multiplex our Bragg grating stabilized pump modules at 5 nm spacings, allowing up to 4 modules to be used within the 970-985 nm EDFA pump band.
High Power Multi-Mode Pump Lasers
SDL has been the worldwide leader in delivering multi-mode pump lasers for a diversity of applications for many years. As new high power optical amplifier technology has developed based on fiber lasers, SDL has developed a pump laser and fiber-coupled module to meet the needs of this emerging technology. Multi-mode lasers can deliver optical powers much greater than single-mode lasers. However, useful operating powers are limited to a range that also delivers high operating reliability. SDL has conducted extensive lifetesting to establish operating conditions that will yield the reliability performance needed for long haul telecommunications deployment.
SDLO-4000 Series is a fourteen (14) pin butterfly package that features high reliability at up to 800 mW from a 104 micron core fiber. By combining our extensive experience with 980 nm single-mode pump lasers for EDFAs and 800 nm multimode lasers for diode pumped solid state lasers, we have developed a 920 nm multimode pump lasers for pumping Ytterbium doped fiber lasers.
SDL-6360 Series of multimode laser diodes feature a wavelength range from 920-980 nm with reliable laser facet powers up to 1.2 W.
High Power DFB Lasers
A growing number of communication networks rely on transmitters that use discrete optical modulators. Such transmitter designs have performance advantages for high fidelity analog video transmission as well as high bit rate digital transmission. High power DFB source lasers help overcome the high optical losses of these discrete modulators and they allow a single source laser to be split across a larger number of fiber optic distribution links.
SDLO-3000 Series is a high power, narrow linewidth DFB laser operating in the 1550 nm wavelength range at output powers greater than 30 mW. Narrow linewidth (>>>
sdli.com
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San Jose, California, February 26, 1998-- SDL Inc.(NASDAQ: SDLI), a market leader in high power semiconductor lasers, announced the first high reliability multimode pump laser module for double-clad fiber amplifiers and lasers at the Optical Fiber Communication Conference in San Jose, California. This module is a key component in the exciting new market for high power telecommunications laser systems based on double-clad rare earth doped fibers. These new fiber amplifiers and lasers feature a single mode fiber core which is pumped through a high numerical aperture cladding layer. This allows the high powers generated with multimode semiconductor lasers to be efficiently converted to single-mode 1550 nm power for use in communication systems. High power fiber amplifiers and lasers are an enabling technology for multi-channel Dense Wavelength Division Multiplexed (DWDM) systems, remote pumping of undersea networks and optical satellite communications. SDL has been the world leader in high power semiconductor pump lasers for over ten years and is one of the leading manufacturers of 980 nm single mode pump lasers for erbium doped fiber amplifiers (EDFAs).
The SDLO-4000 module delivers over 800 mW from a 100 micron fiber at 0.22 NA. The 14-pin butterfly package features an integral cooler which keeps the semiconductor laser at 25°C under case temperature conditions ranging from -20°C to 65°C, preserving the reliability of the device. According to Greg Dougherty, Vice President, Communications and Materials Processing Components Group, “The experience that SDL has gained in manufacturing 980 nm pump lasers for the EDFA market has enabled us to offer a high reliability pump product for the emerging market that includes double clad fiber amplifiers and lasers for telecommunications applications. Several key manufacturing processes are shared in the two products.” In order to qualify the 100 micron broad area semiconductor laser, extensive high temperature accelerated multicell lifetesting was performed based on methodologies developed for 980 nm single mode lasers. The module has been tested for ruggedness and reliability according to strict Bellcore guidelines.
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