NTT Receives IEEE Milestone Recognition for Silica-Based Arrayed Waveguide Grating (AWG)

News Highlights:

Photo 1: Presentation of the commemorative plaque
(Left: Toshio Fukuda, 2020 IEEE President; Right: Akira Shimada, President and CEO of NTT)

About the IEEE Milestone Program

The IEEE Milestone Program honors significant technological innovations and achievements that have benefited humanity. It recognizes unique products, services, seminal papers, and patents that have been internationally acknowledged for at least 25 years and have made substantial contributions to society. The program was established by IEEE in 1983.

Past milestones include foundational technologies and facilities that supported modernization, such as the 19th century telephone, the Edison Laboratory^*2, and Guglielmo Marconi's wireless communications^*3, as well as transformative 20^th-century information and communications technologies, including television, computers, and the Internet.

To date, NTT has received four IEEE Milestone designations as follows:

This latest recognition marks NTT's 5th IEEE Milestone designation.

Photo 2: Commemorative plaque presented by IEEE

Silica-Based Arrayed-Waveguide Grating (AWG)

In optical communications, wavelength-division multiplexing (WDM)^*8 is used to transmit large volumes of data by combining multiple wavelengths of light into a single optical fiber. For example, if each wavelength carries data at 100 Gbit/s and N different wavelengths are used, the total transmission capacity can reach N × 100 Gbit/s. WDM transmission requires wavelength multiplexers and demultiplexers. These devices combine multiple wavelengths into a single fiber for transmission and then separate the combined signal back into individual wavelengths at the receiving end.

Figure 1 Conventional technology

In conventional wavelength (de)multiplexer approaches (Figure 1), diffraction grating-based devices rely on free-space optics, leading to high assembly costs and making them less suitable for mass production. Thin-film filter-based devices, on the other hand, tend to become bulky and complex when handling a large number of wavelengths.

To address these challenges, the AWG wavelength (de)multiplexer based on silica-based planar lightwave circuit (PLC) technology, uses precisedifferences in optical path lengths within waveguides to separate and combine wavelength-multiplexed light carried ina single waveguide. The AWG device features low optical loss, stable performance, high reliability, and excellent mass producibility, while enabling the simultaneous handling of several dozen or more wavelengths (Figure 2). This innovation overcome the challenges of miniaturization and mass production, unlocking the full potential of the ultra-wide bandwidth offered by optical fiber.

Figure 2 Silica-Based Arrayed-Waveguide Grating (AWG)

Widespread Adoption and Contribution to Society

Mass production of AWG wavelength (de)multiplexers began in 1996, following the transfer of the technology from NTT to NTT Electronics Corporation (now NTT Innovative Devices Corporation) and Photonic Integration Research Inc.^*9 The commercialization of high-performance, large-scale, and highly reliable products accelerated the expansion of high-capacity optical communications based on WDM, which gained rapid momentum in the late 1990s.

As a result, this technology played a vital role inbuilding the foundation of today's communications infrastructure, supporting the explosive growth in data traffic driven by the widespread adoption of the Internet.

Subsequent Developments and Current Position

To address growing market demands for higher capacity and greater efficiency, continuous research and development efforts have further advanced AWG wavelength (de)multiplexers. These advancements include miniaturization, reduced optical loss, temperature-insensitive design, and flattened passband characteristics.

Today, AWG wavelength (de)multiplexers remain essential core optical components deployed in telecommunications networks worldwide. They are also serve as key enabling devices for high-capacity transmission in the IOWN All-Photonics Network (APN) promoted by the NTT Group.

[Notes]

^*1 IEEE is the world's largest professional organization, with over 486,000 members across more than 190 countries. Headquartered in New York, it plays a leading role in a wide range of technological fields, including computing, biotechnology, communications, power and energy, aerospace, and electronics.

^*2 A research laboratory where Thomas Edison and his colleagues developed numerous groundbreaking technologies, including the incandescent light bulb, electric generators, and the phonograph.

^*3 In 1895, Guglielmo Marconi successfully conducted the world's first wireless telegraphy experiment, marking the beginning of wireless communications.

^*4 Press release: https://group.ntt/jp/newsrelease/pdf/news2012/1204/120405a.pdf(Japanese)

^*5 Press release: https://group.ntt/jp/newsrelease/pdf/news2014/1405/140522a.pdf(Japanese)

^*6 Press release: https://group.ntt/jp/newsrelease/2015/05/21/150521a.html(Japanese)

^*7 Press release: https://group.ntt/jp/newsrelease/2021/03/05/210305a.html(Japanese)

^*8 Wavelength Division Multiplexing (WDM)
A transmission method that enables high-capacity communications by simultaneously multiplexing multiple optical signals of different wavelengths onto a single optical fiber.

^*9 A joint venture established by the NTT, Mitsubishi Corporation, Mitsubishi International Corporation, and Battelle Memorial Institute.

About NTT

NTT is a leading global technology innovator, providing a broad range of services to both consumers and businesses. As a mobile operator and provider of infrastructure, networks, and services, NTT is dedicated to promoting a sustainable future through cutting-edge innovations. Our portfolio includes business consulting, AI-powered solutions, application services, global networks, cybersecurity, data center and edge computing, all supported by our deep global industry expertise. Generating over $90 billion in revenue and employing 340,000 professionals, we allocate 30% of our annual profits to fundamental research and development. With operations spanning more than 70 countries and regions, our clients include over 75% of Fortune Global 100 companies, alongside thousands of enterprises, government organizations, and millions of consumers.