Monday, January 7, 2013

Deceased--Tingye Li

Tingye Li
July 7th, 1931 to December 27th, 2012

"Tingye Li Dies at 81; Played Crucial Role in Laser’s Development"


Douglas Martin

January 6th, 2013

The New York Times

Tingye Li, an electrical engineer whose calculations in the early 1960s helped guide the development of the laser and propel the dizzying increase in the speed of fiber-optic communication, died on Dec. 27 in Snowbird, Utah. He was 81.

The cause was a heart attack while he was on a family ski trip, his family said. He lived in Boulder, Colo.

Lasers were in the early stage of development when Dr. Li and a colleague at Bell Labs, A. Gardner Fox, developed a computer simulation of how lasers produce the focused light energy that has transformed fields from medicine to space travel. They reported their findings in a paper published in 1961.

Dr. Arno Penzias, a former director of Bell, called their paper a tool kit for subsequent designers of lasers and other optical systems. He said it helped transform the “wonderful invention” of the laser — the word is an acronym for light amplification by stimulated emission of radiation — into “a practical communications platform.”

In essence, the researchers provided a mathematical model for how light bounces about inside a laser between two mirrors as it gathers energy, predicting factors like the shape and intensity of light beams. Alan Willner, an electrical engineering professor at the University of Southern California, called the work “the foundational teaching” on the innards of lasers.

“There aren’t many papers that help define a field, but this was one of them,” he said in an interview.

The research that led to nearly instantaneous communication by light waves was itself snail-like. Dr. Li and Dr. Fox had to write their own programs, punching them into decks of cards, for a room-size computer that was less powerful than a palm-size calculator today. The computer ran the program for two or three hours. A frequent error message meant that the researchers had to scour the cards for a single improperly punched letter, Jeff Hecht wrote in “Beam: The Race to Make the Laser” (2010).

Bell Labs was virtually unchallenged as the largest and most inventive laboratory in the world, having a hand in many of the 20th century’s most important inventions. Dr. Li, who wrote or helped write more than 100 papers, patents and books, led research teams at Bell for more than three decades.

Some of their work laid the groundwork for today’s broadband. One area of study was in finding ways to use light waves to convey information on optical fiber rather than copper wire or radio waves. Another team Dr. Li led developed optical amplifiers, which amplify an optical signal directly without the need to first convert it into an electrical signal.

Dr. Li was an early proponent of using the rare earth metal Erbium in the amplifiers, an improvement that helped raise their capacity more than a hundredfold.

“Tingye Li has shaped the lightwave network infrastructure we know today,” the Institute of Electrical and Electronics Engineers said when presenting him with its Edison Medal in 2009.

Li Ding Yi, as his name is transliterated from Chinese, was born in Nanking, China, on July 7, 1931. His mother, Lily, belonged to the first generation of Chinese women to receive a modern higher education. She became an activist for women’s rights.

His father, Chao, was a Chinese diplomat who was consul general in Vancouver, where Tingye attended middle school, and was later posted to South Africa, where Tingye earned an undergraduate degree in electrical engineering from the University of Witwatersrand. He earned a Ph.D. in electrical engineering from Northwestern University in Evanston, Ill.

Dr. Li joined the Bell Telephone Laboratories (later AT&T Bell Laboratories) in 1957 and worked there until 1998. He worked there with the Nobel Prize recipients Charles Hard Townes and Arthur L. Schawlow, who together invented the maser, which amplified microwaves the way lasers would soon amplify light.

“There was a lot going on and a lot of people helping each other,” Dr. Penzias said.

Dr. Li often quoted Confucius, though friends suspected he occasionally concocted his own learned sayings and then attributed them to the sage. He frequently went to China to help it develop optical communications. The Chinese Academy sent his family a letter at his death praising him for helping China “leapfrog to a higher level” in handling telecommunications traffic.

Dr. Li is survived by his wife of 56 years, the former Edith Wu; his daughters, Deborah Li Cohen and Kathryn Li Dessau; and four grandchildren.

In a speech on his 80th birthday, Dr. Li revealed that he had proposed marriage to his wife for their next life, after they are both reincarnated. She tentatively agreed, he said, if he behaved.

"OSA Mourns the Loss of Tingye Li, 1931-2012, OSA Past President"

Tingye Li, an OSA Past President and Fellow Emeritus renowned for his contributions to lightwave technology and optical fiber communications, died on 27 December 2012 in Snowbird, Utah, USA.  He was 81.

Born in 1931 in Nanjing, Jiangsu Province, China, Li obtained his bachelor’s degree from the University of Witwatersrand, South Africa, and his Ph. D. from Northwestern University, USA.  He joined Bell Telephone Laboratories (later AT&T Bell Laboratories) in 1957, and worked there for 41 years until his retirement in 1998.

During his career at AT&T, Dr. Li authored and coauthored more than 100 journal papers, patents, and books in the areas of antennas, microwave propagation, lasers and optical communications.  He made significant contributions in the fields of lightwave technologies and systems, and he spearheaded research on wavelength division multiplexing transmission systems that revolutionized long-distance telecommunication networks.

In 1961, he and his colleague A. Gardner Fox published a now-classic paper on laser resonator modes, Resonant modes in a maser interferometer, that established the basis for the understanding of the design of optical resonators and how modes in optical resonators behaved.  In the late 1980s, when the whole world’s attention on optical communication was still focused on a single-channel high speed solution, Li and his team at AT&T Bell Labs developed the world’s first (sparse channel) WDM (Wavelength Division Multiplexing) system.  Their experiment in 1992 at Roaring Creek turned out to be a "roaring success" as Li claimed in an interview, allowing 2.5 Gbit/s transmission per channel, the highest rate available at the time. The use of WDM and optical amplifiers changed the paradigm of network economics and is considered to be of revolutionary significance (though evolutionary in design) in the history of lightwave communications.

An OSA member since 1966, Li was named an OSA Fellow in 1977.  He served as an At-Large member of the OSA Board of Directors from 1985-1987, as OSA President in 1995, chaired numerous committees, and was a leader in building the Asia Communications and Photonics (ACP) conference.

Li received many awards and honors during his long and distinguished career.  He was a Fellow of the Institute of Electrical and Electronics Engineers (IEEE), the American Association for the Advancement of Science (AAAS), the Photonic Society of Chinese-Americans, and the International Engineering Consortium.  He was also a member of the U.S. National Academy of Engineering and the Academia Sinica (Taiwan), and a Foreign Member of the Chinese Academy of Engineering.

Li was the recipient of OSA’s John Tyndall Award (1995) and OSA's Frederic Ives Medal/Jarus W. Quinn Prize (1997); IEEE’s W.R.G. Baker Prize (1975), David Sarnoff Award (1979), Photonics Award (2004), and Edison Medal (2009); and the 1997 AT&T Science and Technology Medal.  He was given the 1981 Alumni Merit Award from Northwestern University, and he received Achievement Awards from the Chinese Institute of Engineers/USA (1978), the Chinese-American Academic and Professional Society (1983), and the Photonics Society of Chinese-Americans (1998).  Li was named an honorary professor at many universities in China, including Tsinghua University, Shanghai Jiaotong University, Beijing University of Posts and Telecommunications, Beijing Jiaotong University, Fudan University, Nankai University, Tianjin University, the University of Electronic Science and Technology of China, and Qufu Normal University. He was also named an honorary professor at National Chiao Tung University and National Taiwan University, and he was granted an honorary Doctor of Engineering degree by National Chiao Tung University in Taiwan.

Li was respected and loved as an “elder” among young scientists and engineers in the field of photonics, both for his immeasurable contributions to the field and for his willingness to spend time mentoring, advising, promoting, and encouraging young people.

Tingye Li is survived by his wife, Edith Wu, daughters Deborah (David Cohen) and Kathryn (Daniel Dessau), and several grandchildren.  A memorial service for family, friends and colleagues is being planned for a future date.

Tingye Li [Wikipedia]

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