Alf Adams

{{short description|British physicist}} {{otherpeople2|Alfred Adams}} {{Use British English|date=August 2017}} {{Use dmy dates|date=August 2017}} {{Infobox scientist | name = | native_name = Alfred Rodney Adams | honorific_suffix = {{post-nominals|country=GBR |size=100%|FRS}} | native_name_lang = | image =  | image_size = | alt = | caption = | birth_date = {{Birth date and age|df=yes|1939|11|11}}<ref name="whoswho">{{cite web |url=http://www.ukwhoswho.com/view/article/oupww/whoswho/U4990 |title=ADAMS, Prof. Alfred Rodney |work=Who's Who 2014, A & C Black, an imprint of Bloomsbury Publishing plc, 2014; online edn, Oxford University Press }}{{subscription required}}</ref> | birth_place = | other_names = | residence = | citizenship = | nationality = | fields = | workplaces = {{Plainlist| * University of Surrey * Karlsruhe Institute of Technology * Tokyo Institute of Technology}} | patrons = | alma_mater = University of Leicester (BSc, PhD, DSc) | thesis_title = The electrical and optical properties of ortho-rhombic sulphur crystals | thesis_url = http://www.worldcat.org/oclc/504731974 | thesis_year = 1964 | doctoral_advisor = Walter Eric Spear<ref name="BBC R4"/> | academic_advisors = | doctoral_students = | notable_students = | known_for = Strained quantum-well lasers | author_abbrev_bot = | author_abbrev_zoo = | influences = | influenced = | awards = FRS (1996)<ref name="royal"/> | signature =  | signature_alt = | website = {{URL|surrey.ac.uk/physics/people/alf_adams}} | footnotes = | spouse = | children = }}'''Alfred ("Alf") Rodney Adams''' {{Post-nominals|country=GBR|FRS}} (born 1939<ref name="whoswho"/><ref>[http://www2.cut.ac.cy/digitalAssets/7/7848_seminar4.pdf Cyprus University of Technology]{{Dead link|date=October 2018 |bot=InternetArchiveBot |fix-attempted=yes }}, advertising a lecture to be given by Adams on 4 February 2011. Contains further biographical details.</ref>) is a British physicist who invented the strained-layer quantum-well laser.<ref name=SET2>{{cite web |title=A catalyst to our digital world: strained quantum well lasers—Full Case Study |url=http://www.setsquared.co.uk/impact/communications-case-studies/strained-quantum-well-lasers/catalyst-our-digital-world-straine-1 |website=SET squared |publisher=Universities of Bath, Bristol, Exetor, Southampton & Surray |accessdate=2015-04-02 |archive-url=https://web.archive.org/web/20150403135714/http://www.setsquared.co.uk/impact/communications-case-studies/strained-quantum-well-lasers/catalyst-our-digital-world-straine-1 |archive-date=3 April 2015 |url-status=dead }}</ref> Most modern homes will have several of these devices in their homes in all types of electronic equipment.<ref>{{Cite journal | doi = 10.1109/3.283784| title = Band-structure engineering in strained semiconductor lasers| journal = IEEE Journal of Quantum Electronics| volume = 30| issue = 2| pages = 366| year = 1994| last1 = O'Reilly | first1 = E. P. | last2 = Adams | first2 = A. R. |bibcode = 1994IJQE...30..366O }}</ref><ref>{{Cite journal | doi = 10.1143/JJAP.19.L621| title = The Temperature Dependence of the Efficiency and Threshold Current of In1-xGaxAsyP1-y ''Lasers'' Related to Intervalence Band Absorption| journal = Japanese Journal of Applied Physics| volume = 19| issue = 10| pages = L621| year = 1980| last1 = Adams | first1 = A. R. | last2 = Asada | first2 = M. | last3 = Suematsu | first3 = Y. | last4 = Arai | first4 = S. |bibcode = 1980JaJAP..19L.621A | s2cid = 93124735}}</ref><ref>{{Cite journal | doi = 10.1109/JSTQE.2002.801684| title = A quantitative study of radiative, Auger, and defect related recombination processes in 1.3-μm GaInNAs-based quantum-well lasers| journal = IEEE Journal of Selected Topics in Quantum Electronics| volume = 8| issue = 4| pages = 801| year = 2002| last1 = Fehse | first1 = R.| last2 = Tomic | first2 = S.| last3 = Adams | first3 = A. R. | last4 = Sweeney | first4 = S. J. | last5 = O'Reilly | first5 = E. P. | last6 = Andreev | first6 = A.| last7 = Riechert | first7 = H.| bibcode = 2002IJSTQ...8..801F}}</ref>

He served as a Distinguished Professor of Physics at the University of Surrey, where he headed the Optoelectronic Materials and Devices Research Group. He is now retired and holds the position of emeritus professor. He was awarded the Duddell Medal and Prize in 1995, and elected as a Fellow of the Royal Society in 1996. In 2014 he was awarded the Rank Prize in Optoelectronics for his pioneering work on strained-layer laser structures.

==Early life and education== Adams was born to a non-academic family. His grandmother had died from tuberculosis and his father was born with TB thus being excused from school on medical grounds, before working as cobbler, boxer and gym owner. Adams' mother left school at the age of 12. Adams was evacuated from Hadleigh, Essex during The Blitz in World War II. After taking his eleven-plus exam he attended the local technical school where he represented Southeast Essex at both football and cricket.<ref name="BBC R4"/>

He attended University of Leicester to study physics, in part because he didn't have the foreign language qualifications demanded by most other universities. He also completed his PhD at Leicester with Professor Walter Eric Spear on Orthorhombic crystal systems, before doing postdoctoral research in Physics at Karlsruhe Institute of Technology in Germany, where he met and married his wife Helga.<ref name="BBC R4">[http://www.bbc.co.uk/programmes/b03ynf4y BBC Radio 4, The Life Scientific. Profile of Alf Adams]</ref>

==Career== Back in Britain at the University of Surrey he conducted microwave research using Gallium arsenide crystals under high pressure. In 1980 he took a sabbatical to work on semiconductor lasers at the Tokyo Institute of Technology in Japan.<ref name="BBC R4"/>

After returning to the University of Surrey to continue research. While walking with his wife Helga on Bournemouth beach he realised that by straining semiconductor crystals he could alter the propensity of the electrons to move from low energy to high energy orbits, and vice versa, thus transforming the efficiency of laser light production. The genesis of the strained layer laser (aka strained quantum well laser). He did not patent the idea and so received no financial gain from a technology that is used in virtually every household in the world.<ref name="BBC R4"/>

==Honours and awards== In 1995 he was awarded the Duddell Medal and Prize and in 1996 was elected as a Fellow of the Royal Society.<ref name="BBC R4"/> His nomination for the Royal Society reads: {{quote|Distinguished for his pioneering work on the application of high pressure techniques to the study of semiconducting materials, Professor Adams has done much to advance the use of strain as an important variable in understanding the basic physics of devices. His contributions include the first demonstration of the Gamma-L-X ordering of the conduction band minima in GaAs, the first direct observations of scattering by the central cell potential of impurities, the proposal and experimental confirmation of intervalence band absorption as an important loss mechanism in semiconductor lasers and the prediction that the threshold current in a quantum-well laser can be greatly reduced if the wells are grown in a state of compressive stress. These latter ideas are currently being pursued vigorously around the world where they are resulting in lasers having greatly enhanced performance.<ref name="royal">{{cite web |url=http://royalsociety.org/DServe/dserve.exe?dsqIni=Dserve.ini&dsqApp=Archive&dsqDb=Catalog&dsqCmd=show.tcl&dsqSearch=(RefNo==%27EC%2F1996%2F01%27) |title=EC/1996/01: Adams, Alfred Rodney: Library and Archive Catalogue |publisher=The Royal Society |archivedate=27 March 2014 |archiveurl=https://archive.today/20140327020803/http://royalsociety.org/DServe/dserve.exe?dsqIni=Dserve.ini&dsqApp=Archive&dsqDb=Catalog&dsqCmd=show.tcl&dsqSearch=(RefNo=='EC/1996/01') |location=London |url-status = dead|access-date=26 March 2014 |df=dmy-all }}</ref>}}

Since retirement from the University of Surrey he holds the position of emeritus professor.

In 2014 he was awarded the {{Interlanguage link|Rank Prize in Optoelectronics|ru|Премия Ранка}} for his pioneering work on strained-layer laser structures.

In March 2014 he was the subject of the BBC Radio 4 programme, Professor Jim Al-Khalili's The Life Scientific<ref name="BBC R4"/>

==References== {{reflist}}

== External links == * [https://web.archive.org/web/20080318181350/http://www.ph.surrey.ac.uk/profiles?s_id=25 Biography from the Department of Physics, University of Surrey] * [https://web.archive.org/web/20080518101948/http://www.independent.co.uk/news/uk/this-britain/a-celebration-of-science-in-the-uk-10-britons-who-shaped-our-world-406704.html ''The Independent'': A celebration of science in the UK, 5 July 2006] * [http://www.rankprize.org/ The Rank Prize Funds]

{{DEFAULTSORT:Adams, Alf}} Category:Academics of the University of Surrey Category:British fellows of the Royal Society Category:Living people Category:1939 births Category:Laser researchers Category:People from Hadleigh, Essex Category:Alumni of the University of Leicester