Milestone-Proposal talk:Dynamic single-mode semiconductor laser

Advocates’ Checklist

1. Is proposal for an achievement rather than for a person? If the citation includes a person's name, have the proposers provided the required justification for inclusion of the person's name?
2. Was proposed achievement a significant advance rather than an incremental improvement to an existing technology?
3. Were there prior or contemporary achievements of a similar nature?
4. Has the achievement truly led to a functioning, useful, or marketable technology?
5. Is proposal adequately supported by significant references (minimum of five) such as patents, contemporary newspaper articles, journal articles, or citations to pages in scholarly books? At least one of the references from a peer-reviewed scholarly book or journal article. The full text of the material, not just the references, shall be present. If the supporting texts are copyright-encumbered and cannot be posted on the ETHW for intellectual property reasons, the proposers shall email a copy to the History Center so that it can be forwarded to the advocate. If the advocate does not consider the supporting references sufficient, the advocate may ask the proposer(s) for additional ones.
6. Are the scholarly references sufficiently recent?
7. Is proposed citation readable and understandable by the general public?
8. Does the proposed plaque site fulfill the requirements? Is the address complete? Are the GPS coordinates correct and in decimal format?
9. Is the proposal quality comparable to that of IEEE publications?
10. Scientific and technical units correct? (e.g. km, mm, hertz, etc.) Are acronyms correct and properly upperercased or lowercased?
11. Date formats correct as specified in Section 6 of Milestones Program Guidelines? https://ieeemilestones.ethw.org/Helpful_Hints_on_Citations,_Plaque_Locations

Independent Expert Reviewers’ Checklist

1. Is suggested wording of the Plaque Citation accurate?
2. Is evidence presented in the proposal of sufficient substance and accuracy to support the Plaque Citation?
3. Does proposed milestone represent a significant technical achievement?
4. Were there similar or competing achievements? If so, have the proposers adequately described these and their relationship to the achievement being proposed?

In answering the questions above, the History Committee asks that independent expert reviewers apply a similar level of rigor to that used to peer-review an article, or evaluate a research proposal. Some elaboration is desirable. Of course the Committee would welcome any additional observations that you may have regarding this proposal.

Submission and Approval Log

Submitted date: 16 January 2024
Advocate approval date: 31 July 2024
History Committee approval date: 25 September 2024
Board of Directors approval date: 25 November 2024

Original Citation Title and Text -- Administrator4 (talk) 17:17, 3 April 2024 (UTC)

Single-Mode Semiconductor Laser for Long-Wavelength Optical Fiber Communication, 1978

At Tokyo Institute of Technology, the single-mode semiconductor laser for long-wavelength optical fiber communication was realized and pioneered, ensuring consistent single-mode operations even under high-speed direct modulations. By integrating wavelength-tunable function into a laser cavity, the single-mode laser propelled advancements in high-capacity optical fiber communications, fundamentally shaping our present internet society.

review by Expert No.1 (III/V Semiconductors), Emeritus Prof. Russel D. Dupuis, Georgia Institute of Technology, placed by Advocate -- JaninA (talk) 19:35, 20 July 2024 (UTC)

Emeritus Prof. Russell D. Dupuis, Ph.D. Steve W. Chaddick Endowed Emeritus Professor Georgia Institute of Technology dupuis@gatech.edu School of Electrical and Computer Engineering Center for Compound Semiconductors Georgia Institute of Technology 777 Atlantic Drive, NW Atlanta, Georgia 30332-0250 U.S.A. PHONE 404•385•6094 FAX 404•385•6096

June 22, 2024 RE: Docket #:2023-25 IEEE Milestone Proposal: Dynamic single-mode semiconductor laser To Whom It May Concern:

I strongly recommend that the IEEE approve this nomination for a historical milestone plaque for memorializing the demonstration of the stable single-mode operation of tunable long-wavelength 1.3-1.55 µm semiconductor diode lasers by Suematsu, et al., at the Tokyo Institute of Technology.

As is well described in the Milestone Proposal form, the concept of the distributed-feedback (DFB) laser was first developed by Kogelnik and Shank using a dyed gelatin on a glass substrate using a dye laser in 1971. However, the DFB semiconductor laser diode was not demonstrated until 1974 by Scifres, et al., in the AlxGa1-xAs-GaAs materials system.

The important elements of Suematsu’s work were to apply these concepts to the InGaAsP-InP laser diode to create the first single-mode “long-wavelength” DFB LDs at λ~1.33 and 1.55 µm where the optical losses and dispersion are minimized in high-quality glass optical fibers. The application of these concepts to the InGaAsP system presented many challenges which were successfully overcome by Suematsu and his team.

These innovations and the demonstration of stable single-longitudinal- mode LDs by the Suematsu team provided the critical stable light source technology for the high-bandwidth and high-speed optical fiber data transmission systems that are the backbone of the internet and data and voice telecommunications systems today. This concept and technology set the stage for the development of today’s dense-wavelength division multiplexing device technology and photonic integrated circuit telecom systems. This milestone plaque will provide a physical record of where theseimportant innovations were made.

1. Does the proposed milestone represent a significant technical achievement? Yes 2. Is the suggested wording of the Plaque Citation accurate? Yes 3. Is the evidence presented in the proposal of sufficient substance and accuracy to support the Citation? Yes 4. Were there similar or competing achievements (and) have the proposers adequately described these and their relationship to the achievement being proposed? Yes. The related historical basis of this work is adequately described.

Sincerely,

Emeritus Prof. Russell D. Dupuis, Ph.D. Steve W. Chaddick Endowed Emeritus Professor Georgia Institute of Technology School of Electrical and Computer Engineering

review by Expert No. 2 Prof Larry Coldren (Semiconductor Lasers), Fred Kavli Professor Emeritus, University of California, Santa Barbara placed by the advocate Janina Mazierska -- JaninA (talk) 17:07, 25 July 2024 (UTC)

Review of: Dynamic single-mode semiconductor laser, Docket #2023-25 By Larry A. Coldren, Fred Kavli Professor Emeritus, University of California, Santa Barbara

SUMMARY OPINION: I strongly recommend this proposal for inclusion as an IEEE Milestone. I have known Prof. Suematsu since the 1970s and his work has greatly influenced the semiconductor laser field for optical communications. In fact, the entire world followed his lead in choosing the materials and designs to make lasers for long distance fiber optic communications in the critical years of the late 1970s and early 1980s. Moreover, he educated most of the leading industrial Japanese researchers and managers who led the world in such laser production during the 1980s. He is very deserving of this recognition.

DETAILED REVIEW:

1. Does the proposed milestone represent a significant technical achievement? 

Yes, additional positive comments added below

2. Is the suggested wording of the Plaque Citation accurate? 

Yes

3. Is the evidence presented in the proposal of sufficient substance and accuracy to support the Citation?   

Yes, and some comments are added below.

4. Were there similar or competing achievements; have the proposers adequately described these; and their relationship to the achievement being proposed?  

Mostly, but here also some comments are added below.

SUPPLEMENTAL COMMENTS:

  Before anyone else, Prof Suematsu made a commitment to focus on the InGaAsP/InP materials for long distance fiber optic communications in the 1970s.  He also realized that single-frequency, single-mode lasers at 1550nm were necessary to carry information over long distances.  Of course, he was correct.  So, he led his students to develop the world’s first lasers with these characteristics.   The rest of the world followed but several years later.  The impact of this work cannot be overstated; it was truly revolutionary.   
  Another very important point which is not emphasized in the nomination is that he educated students who would become the leaders of most of Japan’s semiconductor laser industry for fiber optic communications in the 1980s-2000.  This may have been his most important contribution.  The impact of this fact cannot be overstated as well.  
   His group developed rather complex Distributed-Bragg-Reflector (DBR) laser designs that involved multiple regrowths of different III-V semiconductor alloys.  This technology also helped Japanese industry become leaders in long wavelength laser manufacturing in the 1980s.  The DBR designs were also naturally electronically tunable by applying currents to the passive regions, and with his students he was able to demonstrate the first tunable lasers in the long-wavelength area.
  DBR laser designs were also emulated around the world for tunability.  However, most single-frequency lasers in most industries, both in Japan and elsewhere, evolved toward Distributed-FeedBack (DFB) designs, mainly because only single contacts were needed, and they remained single-mode over temperature.  DBRs required electronic control to remain single-mode over temperature.        
  Not to take away from this nomination, but widely-tunable semiconductor lasers actually developed more rapidly in the US and Europe than in Japan.  (Japanese industry actually preferred arrays of DFBs to cover wide wavelength spans.)   Clearly, Prof. Suematsu’s group developed the first tunable long wavelength DBR lasers as stated above, and Suematsu indicated their potential importance as well.   Additionally, the nomination correctly indicates the impact that widely-tunable lasers later had—dating well into the 2000s.   But, the nominator seems to gloss over the point that the basic principles of the mentioned SG and SSG-DBRs [1993 references B10 and B9 in the nomination] were contained in a 1990 patent by Coldren, ‘multi-element mirror laser’, and there were several publications on the SG-DBR in 1991 and 1992 prior to the1993 references.  [See references (12-16) in B10, which is a review paper]. 
 Again, this slight oversight by the nominator should not take away from the inherent strength of the case for Prof. Suematsu, whose seminal contributions for this recognition were mainly in the 1970s and 1980s, with impacts reaching to this day.

Expert Review 3 by Prof. Emerita Connie Chang-Hasnain (Semiconductor Lasers), University of California, Berkeley placed by advocate Janina Mazierska -- JaninA (talk) 19:37, 26 July 2024 (UTC)

BERKELEY • DAVIS • IRVINE • LOS ANGELES • RIVER SIDE • SAN DIEGO • SAN FRANCISCO UNIVERSITY OF CALIFORNIA, BERKELEY SANTA BARBARA • SANTA CRUZ

Connie Chang-Hasnain Whinnery Chair Professor Emerita of Electrical Engineering E-mail: cch4602@gmail.com and Computer Sciences Department (cell) (650) 799-7355

July 26, 2024

Dear IEEE History Committee,

It is my distinct pleasure and honor to write this letter with my most enthusiastic support of the IEEE Milestone proposed by Professor Emeritus Fumio Koyama of the Tokyo Institute of Technology.

Before reviewing the milestone proposal, please allow me to formally introduce myself and establish my credibility as a reviewer. I am Whinnery Chair Professor Emerita of EECS at the University of California, Berkeley, and Chairperson of Berxel Photonics, Inc. I was John R. Whinnery Chair Professor (2006-2020), Associate Dean for Strategic Alliances in the College of Engineering (2014-2019), and Chair of the Nanoscale Science and Engineering Graduate Group (2006-2017) at the same university. I was the Editor- in-Chief of Journal of Lightwave Technology 2007-2012. I am the President of Optica (formerly OSA) in 2021. I am a Fellow of IEEE, Optica, and IEE, and a member of the US National Academy of Engineering. My expertise lies in semiconductor lasers, particularly vertical-cavity surface -emitting lasers, and nano- photonics, with over 40 years of experience. I have received numerous prestigious scientific awards, including the 2024 Nick Holonyak Jr. Medal for Semiconductor Optoelectronic Technologies, the 2018 Okawa Prize, the 2017 Optica Nick Holonyak Jr. Award, and the 2011 IEEE David Sarnoff Award.

First, I would like to elucidate the impact and significance of the technical achievements in the proposed milestone as an expert in semiconductor lasers. To realize the information society, scientists and engineers have undertaken the challenge of innovating communication technology. Information technology permeates and revolutionizes various aspects of our lives, including economic activity, culture, education, and daily living. The Optical fiber communication network is the cornerstone of the present information society. In 1966, Charles Kao (2009 Nobel Prize in Physics Laureate) theoretically predicted the feasibility of low-loss optical fiber. The primary challenge was to develop an optimal laser for optical fiber communication. To ensure information could be transmitted without attenuation over distances of several tens or hundreds of kilometers, a semiconductor laser operating in a low-loss, long-wavelength band was required. Prior to the proposed milestone achievement, long-distance information transmission was hindered by fiber dispersion when various wavelengths of light were mixed.

Professor Yasuharu Suematsu at Tokyo Institute of Technology conducted pioneering research on optical communications since the early days of optoelectronics. His research encompassed the suitability of high- speed modulated semiconductor lasers as light sources for optical communications and the broad-band characteristics of optical fibers. From the outset, Dr. Suematsu and his colleagues at Tokyo Institute of Technology aimed to achieve long-distance, high-speed optical fiber transmission. in 1979, they were the first in the world to achieve continuous operation at room temperature of a long-wavelength semiconductor laser. They selected GaInAsP (Gallium Indium Arsenide Phosphide) as the laser material, recognizing its potential for long waveband oscillation, although its crystal growth and other characteristics had not been fully demonstrated. For the first time, they achieved semiconductor laser oscillation in the 1550 nm wavelength band. However, despite silica fiber exhibiting the smallest propagation loss in the 1550nm wavelength band, the large material dispersion in this band posed an obstacle to its implementation for long-distance, wide-band transmission.

Dr. Suematsu hypothesized that this dispersion issue could be mitigated by limiting the oscillating modes of the semiconductor laser itself. He then undertook the challenging task of developing a semiconductor laser whose wavelength purity and precision remained stable under rapid modulation and varying ambient temperatures. This laser was named the dynamic-single- mode laser in 1980. In pursuit of its development, he invented an integrated twin-guide laser around 1975, introducing a novel single-mode semiconductor laser. Based on the entirely new concept of selective oscillation of one wavelength through optical interference between the active layer and nearby waveguide, the effectiveness of this laser was first demonstrated theoretically. By 1981, it was realized as a single- mode long-wavelength device with a distributed reflector. The development of a laser that maintained mode purity even under rapid modulation in the Gigahertz range received high acclaim at international conferences.

Anticipating future needs, in 1983, he developed the world’s first tunable semiconductor laser, with electronically adjustable wavelength, as an essential device for realizing ultra-wideband optical communications. This innovation paved the way for terabit-per-second wavelength division multiplexing (WDM) optical networks that became prevalent by the late 20th century. As awareness of this groundbreaking technology grew, it spurred the development of various devices and became the foundation for the widespread availability of high-capacity optical fiber communications today. It realized the concept of integrating multiple functions on a single device rather than using individual laser diodes. His pioneering research and development efforts, particularly in realizing the dynamic-single-mode semiconductor laser, have significantly contributed to the implementation of long-distance and high-speed optical fiber communications, earning him numerous awards and honors both in Japan and internationally.

I firmly believe that the proposed milestone achievement on single-mode long-wavelength lasers represents the highest quality research, widely recognized as outstanding and leading in the technical area of semiconductor optoelectronics. It is crucial to emphasize that the achievement of this proposed milestone has greatly contributed to the realization of high-capacity, long-distance optical fiber communication. The long-wavelength single-mode laser has proven to be an indispensable technology in the field of optical fiber communication, both past and present. By the mid-1980s, technology utilizing optical fiber for long- distance communication was established and began to be employed as intercity and international communication infrastructure. It is fair to say that the Internet, which became widespread among the general public from 1995 onwards, would not have been possible without this technology.

In summary, Prof. Suematsu’s work has made seminal contributions which created monumental impact and guided the developments of the optical fiber communications industry. The proposed citation: “Single- Mode Semiconductor Laser for Long-wavelength Optical Fiber Communication” is highly appropriate, with overwhelming evidence to support the citation. I provide this proposal with my strongest support. I strongly urge the Committee to consider his nomination favorably. Please do not hesitate to contact me if you need more information.

Yours sincerely,

Connie Chang-Hasnain

Expert review 4 by Dr Hideo Kuwahara of Fujitsu Ltd, IEEE Life Fellow (Optical Communication Systems) place by advocate Janina Mazierska -- JaninA (talk) 08:41, 31 July 2024 (UTC)

Prof Mazierska, Past Chair of the IEEE History Committee

It is my pleasure to write my review on the IEEE Milestone proposal “Single-Mode Semiconductor Laser for Long-wavelength Optical Fiber Communication”, which was nominated by Professor Emeritus Fumio Koyama of Tokyo Institute of Technology. I had undertaken leading research of large-capacity optical fiber communications in Fujitsu Ltd. for over 40 years. I was also appointed President of the IEEE Photonics Society for dedicating to the advancement of the theory and practice of photonics in 2012-2013. I have known the research activity on semiconductor lasers at Tokyo Institute of Technology since around 1974 and followed the pioneering work on Single-Mode Long-wavelength Semiconductor Laser ever since. I would like to address several statements on the proposed IEEE Milestone as an expert of optical fiber communication systems.

1) Historical significance of the achievements in the proposed milestone A) Single-mode Long-wavelength Semiconductor Lasers Tokyo Institute of Technology can truly be regarded as a leading research institute in semiconductor lasers worldwide. The team of Dr. Yasuharu Suematsu was extensively involved in the development of single-mode semiconductor lasers at the low-loss wavelength band of silica fibers in the 1.3-μm and 1.5-μm band with GaInAsP/InP long-wavelength materials. The first demonstration of single-mode lasers, emitting at 1.3 μm and 1.5 µm were realized at in 1980. The novel idea of the “dynamic single longitudinal-mode laser” at Tokyo Institute of Technology was materialized, which enables to maintain a stable wavelength even with high-speed direct modulation. The achievement has greatly contributed to the realization of high-capacity, long-distance optical fiber communication and also high-capacity datacenter networks today. In 1974, a single-mode laser was proposed that oscillates light with a uniform wavelength by placing two periodic structure reflectors within the integrated “waveguide” and creating an intermediate region between the respective reflectors so that half of the wavelength phase is deviated. Furthermore, when it was discovered in the 1970s that light loss within the optical fiber is minimal when the wavelength band is 1.5 micrometers. The team of Tokyo Institute of Technology succeeded in the room-temperature continuous-wave operation of 1.5 micrometer wavelength using an InGaAsP laser. In the fall of 1980, by means of an integrated laser with a unique periodic structure reflector, they succeeded in creating a prototype for a 1.5 micrometer wavelength band laser. It was verified that light oscillation was stable even under high-speed modulation to transmit data, and in the following year (1981), at an academic conference in Europe, this invention was presented as a “dynamic single-mode laser.” The dynamic single-mode laser proved to be indispensable for use in optical fiber communication at present. By the mid-1980s, long-distance optical fiber communication was established and began to be used as key communication infrastructure worldwide.

B) Wavelength Tunable Semiconductor Lasers The proposed milestone also contributed to the advancement of integrated laser technology. In 1983, the research team at Tokyo Institute of Technology became the first in the world to achieve a wavelength tunable semiconductor laser that can electrically control the oscillation wavelength. Entering the mid-1990s, a new technology, wavelength division multiplexing (WDM), was introduced into optical fiber communication to achieve a higher-capacity communication network, and the technology pioneered by the proposed milestone has greatly contributed to this development. Wavelength tunable lasers are of paramount importance in modern telecom systems as they can be used to populate different channel slots and reduce laser inventory. In addition, they can also provide a route to reconfigurable WDM systems.

2) Impacts to our digital society In today's interconnected world, optical fiber communications play a vital role in enabling global communication and data transfer. These remarkable systems form the backbone of international connectivity, facilitating seamless transmission of vast amounts of information across continents. From undersea depths to land-based networks, they provide the lifeline for our digital society. The fiber optic cable network spans thousands of kilometers, connecting countries and continents with lightning-fast data transmission capabilities. It enables us to communicate, conduct business, and share knowledge on a global scale. I would say this intricate infrastructure relies on cutting-edge technology, including the landmark achievements of the proposed milestone.

3) Proposed plaque citation and the evidence to support the citation The proposal is well-organized to show a proper plaque citation with the evidence to support the citation. In addition, competing achievements and related work have been described in the proposal.

In summary, the proposed milestone achievement opened a research field of single-mode semiconductor lasers & tunable lasers, and received high recognition for the pioneering work. The international scientific community holds the outstanding pioneering accomplishments and contributions to optical fiber communications in the highest esteem. The invention, fundamental, and experimental breakthroughs in the proposed milestone have proven to have had a lasting impact on today’s Internet society. Based on my qualification and expertise, I strongly support the proposal to the IEEE Milestone.

          July 30, 2024                       
Hideo Kuwahara, Ph.D.

Honorary Fellow, Fujitsu Limited Life Fellow IEEE, Past President of the IEEE Photonics Society

Advocate decision -- JaninA (talk) 08:56, 31 July 2024 (UTC)

Based on four supporting expert reviews (from four IEEE Fellows) I approve the milestone nomination 2023-25 for consideration by the IEEE History Committee.

Janina

Advocate decision -- JaninA (talk) 08:57, 31 July 2024 (UTC)

Based on four supporting expert reviews (from four IEEE Fellows) I approve the milestone nomination 2023-25 for consideration by the IEEE History Committee.

Janina

The revision of descriptions on related other work and the addition of related references by the nominator -- Fumio Koyama (talk) 10:27, 7 August 2024 (UTC)

The description of related other work was revised by the nominator according to Larry Coldren’s comments as below. Also, three more references were added as listed.

A sampled grating WT-LD with an extremely wide tuning range was proposed in 1988 [B9] and demonstrated in 1992 [B10] by Coldren’s group of UC Santa Barbara. Also, the tuning range was expanded using superstructure gratings by Tohmori et. al. in 1992 [B11]. 

[B9] L.A. Coldren, “Multi-section tunable laser with differing multi-element mirrors,” U.S. Patent, 4896325, Jan. 1990, (filed in Aug. 1988). [B10] V. Jayaraman, L.A. Coldren, S. Denbaars, A. Mathur, and P.D. Dapkus, “Wide tunability and large mode-suppression in am-section semiconductor laser using sampled gratings, Proc. of Integrated Photonics Research, paper WF1-1, New Orleans, Apr. 1992. [B11] Y. Tohmori, Y. Yoshikuni, T. Tamamura, M. Yamamoto, Y Kondo and H. Ishii, "Ultrawide wavelength tuning with single longitudinal mode by super structure grating (SSG) DBR lasers", 13th IEEE Laser Conf., Sep. 1992.

Approval of corrections made by the nominator by Expert No 2, Prof Larry Coldren posted by the advocate -- JaninA (talk) 17:01, 7 August 2024 (UTC)

Expert No 2, Prof L. Coldren emailed me on August 6, 2024 that he was satisfied with a redacted description of his invention as well as of additional three references.

Milestones Subcommittee Chair Comment -- Bberg (talk) 19:10, 12 September 2024 (UTC)

I have been helping with the citation for this Milestone. Some weeks back I proposed new wording which was accepted. In revisiting the citation, I thought it could still be improved. As such, the current citation was the result of my conferrring with my associate Giacomo Vacca related to my further tweaks. I think it reads very nicely now.

Brian Berg, Milestones Subcommittee Chair