Integration makes waves for the future

Jun 1st, 2001
0601talkingtech1

A DISCUSSION WITH J. J. PAN OF LIGHTWAVES 2020

BY CONARD HOLTON

J J. Pan is founder and chairman of Lightwaves 2020. Along with his wife, he cofounded E-Tek Dynamics, which merged with JDS Uniphase in 2000. A pioneer in the fiberoptic industry, he worked on coarse WDM projects for the US Department of Defense as early as 1976. He has consistently pursued his interests in the field of microwave and millimeter-wave fiberoptics and other advanced component and system technologies. Pan received his education from the National Taiwan University and Harvard University.

WDM Solutions: You have created a new company, Lightwaves 2020. What was your primary motive is starting a new company at this time?

Pan: The fiberoptic industry is evolving from simple point-to-point connections to true networks with multiple interconnects and channels. At the same time that fiberoptic systems are evolving into more sophisticated networks, fiberoptic component manufacturers are under tremendous pressure to provide higher-performance devices at lower cost for the network carriers and system equipment manufacturers. This pressure creates opportunities for significant revenue and profit generation for innovative component manufacturers.

Lightwaves 2020 is built upon my own base of more than 28 years of accumulated technology development and manufacturing experience in the fiberoptic component industry, as well as the extensive experience base of my key colleagues, whom I have worked with over these many years. This core team is combined with some of the best young engineers in the industry. We have just completed our state-of-the-art corporate headquarters, research laboratories, and production facilities in Milpitas, CA.

Our initial production integrates advanced fabrication techniques with innovative designs to create fiberoptic components and subsystems. We have placed particular emphasis on our package integration capabilities for immediate volume production at reduced cost.

The fiberoptic industry has been—and will continue to be—my life's work. I founded Lightwaves 2020 to benefit our industry with advanced fiberoptic components and subsystems today, and to create the research platform that will deliver truly breakthrough technologies in the future. And personally, it is both invigorating and gratifying to coach talented young engineers, giving them the opportunity to advance both technically and financially.

WDM Solutions: So what is your primary technical direction; what sorts of products do you intend to produce?

Pan: Future telecommunications applications will need faster, smaller, more cost-effective, and reliable optical components. Traditionally, DWDM systems have been built by assembling various discrete components. To meet the demand for volume components, and facing the reality of a lack of submicron automation manufacturing equipment, Lightwaves 2020 is developing an integration platform of active and passive components. These components offer greatly increased reliability and functionality while reducing device size and cost, and simplifying packaging. The additional advantages of these integrated devices are improved signal-to-noise ratio and lower power consumption.

We have applied innovative designs and advanced thin-film technologies to produce planar integrated and vertically integrated fiberoptic devices, components, and subsystems. We anticipate these new products will change the way equipment providers design for both long-haul and metro fiberoptic infrastructures. For example, we are developing new materials fabrication technologies, thin-film deposition technologies, and fiber-Brag-grating techniques that incorporate the faster speeds of modulators and variable optical attenuators [VOAs]. We are also developing larger array integration of isolators and circulators, denser channel spacing for wavelength multiplexers/ demultiplexers, and broader tuning and modulation for fiber lasers.

WDM Solutions: Are you making the fiber laser yourself? What are the advantages?

Pan: We are applying fiber-Bragg-grating [FBG] techniques to fabricate an erbium/ytterbium [Er/Yb] co-doped fiber laser. FBG is a well-developed technique to write grating patterns on the fiber core while employing a phase mask with UV illumination. Our engineers have demonstrated the fiber laser, which has several advantages such as precise wavelength selection, good temperature stability, low intensity noise, narrow line width, and excellent tunability. It is unlike the multi-electrode DFB [distributed feedback] or DBR [distributed Bragg reflector] tunable laser diodes, which possess the shortcoming of mode hopping. The fiber laser has a continuous tuning range of 12 to 20 nm. We purchase Er/Yb co-doped fiber and pump laser diodes and fabricate the FBG fiber ourselves to produce an interactive fiber laser with an active length of only 4 to 6 cm.

WDM Solutions: How easily, to what extent, and how soon can these components be integrated with each other?

Pan: Our company has extensive experience in the packaging integration of various components. This integration, combined with innovative designs and proprietary material fabrication techniques provides the technical base for volume production at reduced manufacturing cost. For example, we are integrating crystalline thin-film materials into VOAs and polarization controllers, while fabricating fiber grating lasers by integrating FBG and semiconductor fabrication techniques. We are also developing multiple-channel wavelength-transmitter modules and subsystems by integrating in-house developed components such as a fiber laser, high-speed electro-optic modulator, VOA, and polarization controller. We hope to bring the integrated subsystems to market in the near future.

WDM Solutions: How has your background in semiconductor and microwave components/subsystems affected the technical direction of your company?

Pan: Microwave and fiberoptic communications have many analogies and similarities in device operation principles, performance parameters, and system design issues. For example, masers and lasers are operated with a similar cavity principle. Amplifiers and oscillators are analogous to EDFAs [erbium-doped fiber amplifiers] and laser diodes in terms of performance parameters. Both technologies need to address dispersion, group delay, and polarization issues, including polarization-mode dispersion [PMD] and polarization-dependent loss [PDL]. Therefore, we draw on the experience of microwave's design and fabrication techniques to create our fiberoptic components. For example, microstrip electrodes, coplanar waveguides, impedance matching, and velocity matching designs are applied to the fabrication of modulators. Interleavers for dispersion-slope compensation and filtering are related to the comb generator in microwave components.

The semiconductor industry has developed many mature fabrication techniques in the past decade that could be very beneficial to the fiberoptic component industry. For example, fabrication of fiberoptic components requires submicron accuracy, and the semiconductor industry is working on 0.13- to 0.18-µm line-width features. There is a great opportunity for us to integrate these techniques into the fiberoptic industry. Thin-film deposition techniques such as high-vacuum e-beam evaporation for multiple-cavity coating, MOCVD [metal-organic chemical-vapor deposition] for crystalline thin-film materials, silicon-wafer micromachining for precision micro-optic benches, and reactive ion etching [RIE] for waveguide fabrication are just some other examples of how semiconductor fabrication techniques can play a role in fiberoptics.

WDM Solutions: How are you setting up production—will you rely heavily on automation or on a skilled labor force?

Pan: As I mentioned, we have extensive experience in semiconductor fabrication techniques. We are leveraging these technologies to integrate special packaging and highly reliable fabrication techniques with manufacturable processes to minimize the need for automation or a skilled assembly labor force. Our new facility provides us with state-of-the-art equipment, such as a plasma-assisted e-beam coater, MOCVD system, mask aligner, reactive ion miller, and RIE system to produce all the devices in house. Since there is no such diverse fabrication equipment available outside, we are making every effort to build up our own manufacturing capabilities.

WDM Solutions: Have you had difficulty recruiting staff in this competitive environment?

Pan: Fortunately, because of our unique technologies, our track record, and our growth potential, we have been very successful in recruiting an exceptionally qualified and talented staff. Lightwaves 2020 employs a multidisciplinary development team of engineers, scientists, and manufacturing engineers with proven records in advanced optical-device designs, materials processing, and component manufacturing. We encourage our team to be creative, innovative, and unique in their product designs, and we maintain a hardworking spirit during product development.

WDM Solutions: You have extensive relationships in China. How is the development of optical networking technology progressing there?

Pan: I have been observing China's fiberoptic activities over the past 20 years. They do have very good researchers in universities and research institutes, but lack the manufacturing capabilities. Not until recently have firms such as E-Tek/JDS Uniphase and other US component manufacturers started to build production facilities in China. We are aware of China's purchases of some turnkey telecommunication equipment from Lucent and other equipment manufacturers. Because Lightwaves 2020 is targeting the development and application of next-generation fiberoptic components and subsystems, our market is mainly North America and Europe.

WDM Solutions: What are the main business opportunities for overseas firms in China?

Pan: Several western companies, such as Lucent, Nortel, and Alcatel, are selling high-speed multi-Gbit/s turnkey communication systems to China while Japanese companies are delivering laser diodes. As I mentioned, E-Tek/JDS Uniphase, along with Oplink, Avanex, and NewFocus, have started production of passive fiberoptic components in China. Sooner or later, China can manufacture these low-cost passive components such as couplers, isolators, and circulators themselves. The main opportunities in China, with export approval, will be test instruments, CATV equipment, active components, and turnkey systems.

WDM Solutions: Finally, what types of technologies particularly interest you for the future development of low-cost, flexible optical networks?

Pan: Electro-optic [EO] polymers are very attractive for fiberoptic component technologies such as high-speed switches and modulators. Their many advantages over lithium niobate or other inorganic crystals include low dielectric constant and high nonlinear optical properties. Another important advantage of the polymer approach is its potential for large-scale integration with low cost. Our engineers can synthesize selected chromophores and host polymers to form EO polymers with large EO coefficients. Currently, we are evaluating their long-term high temperature stability and optical stability. Hopefully, practical high-speed devices will be available within 18 months.

In the meantime, we're also performing extensive R&D on devices for polarization-division multiplexing/demultiplexing (PDM). The PDM/WDM system approach can cost-effectively increase today's dense WDM capacity many times over. However, implementing this approach in fiberoptic networks will be determined by the overall system design.

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