physics

Sajeev John

Sajeev John is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Sajeev John rather than just read about it. In short: Sajeev John, OC, FRSC (born 1957) is a Professor of Physics at the University of Toronto and Canada Research Chair holder. He is known for his discovery of photonic crystals.

Key takeaways

Sajeev John belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Sajeev John to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Sajeev John from memory before moving on to harder problems.

Reference excerpt

Sajeev John, OC, FRSC (born 1957) is a Professor of Physics at the University of Toronto and Canada Research Chair holder. He is known for his discovery of photonic crystals.

Education and career He received his bachelor's degree in physics in 1979 from the Massachusetts Institute of Technology and his Ph.D. in physics at Harvard University in 1984. His Ph.D. work at Harvard introduced the theory of classical wave localization and, in particular, the localization of light in three-dimensional strongly scattering dielectrics. From 1984 to 1986 he was a Natural Sciences and Engineering Research Council of Canada postdoctoral fellow at the University of Pennsylvania, as well as a laboratory consultant to the Corporate Research Science Laboratories of Exxon Research and Engineering from 1985 to 1989. From 1986 to 1989 he was an assistant professor of physics at Princeton University. In 1987, while at Princeton he co-invented, along with Eli Yablonovitch, the concept of a new class of materials with a photonic band gap called photonic crystals. This provided a fuller explanation of his original conception (1984) of the localization of light. He was a laboratory consultant to Bell Communications Research (Red Bank, NJ) in 1989. In the fall of 1989 he joined the senior physics faculty at the University of Toronto. He has been a Principal Investigator for Photonics Research Ontario and is a fellow of the Canadian Institute for Advanced Research.

Recognition John is the winner of the 2001 King Faisal International Prize in Science, which he shared with C. N. Yang. He is also the first ever winner of Canada’s Platinum Medal for Science and Medicine in 2002. Dr. John is the winner of the Institute of Electrical and Electronics Engineers (IEEE) LEOS International Quantum Electronics Award in 2007 for “the invention and development of light-trapping crystals and elucidation of their properties and applications.” He is the 2008 winner of the IEEE Pioneer Award in Nanotechnology and the 2013 IEEE David Sarnoff Award. In 2011, John was selected as a Thomson-Reuters Citation Laureate. John was awarded the Killam Prize in Natural Sciences for 2014 by the Canada Council for the Arts. In 2017, he was appointed as an Officer of the Order of Canada "For his revolutionary contributions to optical sciences, notably for his role in the development of new structures capable of harnessing the flow of light." In 2021, John was awarded the Herzberg Canada Gold Medal by the Natural Sciences and Engineering Research Council of Canada. He was elected a Fellow of the Royal Society in 2025. Dr. John also received the 1996 Herzberg Medal for Physics and the 2007 Brockhouse Medal for Condensed Matter and Materials Physics from the Canadian Association of Physicists. He received the first ever McLean Fellowship from the University of Toronto in 1996, the 1997 Steacie Prize in Science and Engineering from the National Research Council of Canada, and the 2004 Rutherford Medal from the Royal Society of Canada. He is the first ever winner of Brockhouse Canada Prize in 2004, which he shared with materials chemist Geoffrey Ozin for their groundbreaking interdisciplinary work on photonic band gap materials synthesis. Professor John has also received the Killam Fellowship of the Canada Council for the Arts, the Guggenheim Fellowship (USA), the Japan Society for the Promotion of Science Fellowship, and the Humboldt Senior Scientist Award (Germany). In 2007, Dr. John was awarded the C.V. Raman Chair Professorship of the Government of India. Prof. John is a Fellow of the American Physical Society, the Optical Society of America, the Royal Society of Canada, and a member of the Max Planck Society of Germany. He was the 2011 Elizabeth R. Laird Lecturer at the Memorial University of Newfoundland.

References

External links Sajeev John's University of Toronto home page Why trap light? Photonic Band Gap Materials: Semiconductors of Light (YouTube) Photonic Crystals Increase Solar Cell Efficiency (YouTube)

Worked examples

Example 1 — a first encounter with Sajeev John

Start with the simplest possible case. Write down what Sajeev John claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Sajeev John before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Sajeev John ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Sajeev John

In research: Sajeev John appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Sajeev John in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Sajeev John is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1957 births, 20th-century Indian physicists, 21st-century Indian physicists, so understanding it makes those chapters shorter.
In everyday life: Look for Sajeev John outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Sajeev John in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Sajeev John means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Sajeev John out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sajeev John in simple terms?

Sajeev John, OC, FRSC (born 1957) is a Professor of Physics at the University of Toronto and Canada Research Chair holder. He is known for his discovery of photonic crystals.

Why does Sajeev John matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Sajeev John?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Sajeev John.