Photonics: Technological Platform for the 21st Century

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Photonics Technological Platform for the 21st
Century
Dr. Ping Koy Lam Department of Physics, The
Australian National University, Canberra, ACT
0200, Australia. E-mail Ping.Lam_at_anu.edu.au
http//photonics.anu.edu.au
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What is Photonics?

• "Photonics is the technology of generating and
  harnessing light and other forms of radiant
  energy whose quantum unit is the photon. The
  science includes light emission, transmission,
  deflection, amplification and detection by
  optical components and instruments, lasers and
  other light sources, fibre optics,
  electro-optical instrumentation, related hardware
  and electronics, and sophisticated systems. The
  range of applications of photonics extends from
  energy generation to detection to communications
  and information processing."
• (The Photonics Dictionary, Laurin Publishing)

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What is Photonics in Simple Terms?

• Almost everything you can do with electricity,
  you can do with light better!
• Photonics is about using light to perform tasks
  that we normally do with electricity and more...

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Why Use Photons?

• Photons are very small
• Provides fine control to many applications

• It is massless, yet it has momentum!
• Effective Mass Planck / (Wavelength Light
  speed)
• There is a minimum size to structures it can
  penetrate.

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Why Use Photons?

• Photons travel in straight lines
• Very handy as a ruler for measuring distance

• When traveling in vacuum it defines what
  straightness is!
• We would rather say that space is curve! But
  photons travel in straight lines.

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Why Use Photons?

• Photons are very fast
• Good for tele-communication.

• Speed of light is
• c 299,792,458 m/s
• Nothing travels faster than light
• It also oscillate very fast
• f gtgt 1,000,000,000,000,000 Hz is very easy.

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Why Use Photons?

• Photons have colors - Bandwidth
• Different colors can be use to represent
  different channels. We can simultaneously use
  many light channels.

• Its color (wavelength) is dependent on its
  frequency of oscillation.
• Speed of light Color Frequency

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Why Use Photons?

• Photons interact readily with atoms
• Extremely small tweezers to manipulate atoms
  with. Essential for future nanotechnologies.

• Absorption
• Spontaneous Emission
• Stimulated emission
• Atomic dipole interaction

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Why Use Photons?

• Photons have many other weird properties!
  (quantum-ness)
• Future Quantum Technologies!

• Polarization
• Discrete packets
• Nonlinear
• Social (Bosons)
• Wave-particle duality
• Vacuum is full of virtual photons
• Superpositions and Entanglement

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Examples 1

• Communication
• Smoke signal gt Homing Pigeons gt Electrical
  Telephone gt Optical Fibre

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Examples 2

• Clock
• Hourglass gt Mechanical Clock gt Quartz Clock gt
  Atomic Clock
• 1sec 9,192,931,770 oscillation of 133Cs55
  transition.

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Examples 3

• Music
• Gramophone gt Magnetic tape recorder gt CD and DVD
  players

DVD disc can store about 3000 songs (about
equivalent to 300 vinyl record). Sound quality
is higher The songs stored are more robust
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Other examples

• Business Bar code, scanning and copying
• Visual arts Laser show holograms
• Medical breath analysis
• Distance measurement
• Gyroscope and GPS.
• Optical memory
• Cooling
• Forensics
• Medical surgery
• Dentistry
• Machining

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Examples 4

• Calculation
• Stonehenge, Pyramid of Egypt, Sky measurer of
  China
• (Calculate seasons and astronomical events)
• Pebbles and abacus
• (Provide visualization of a rather abstract
  concept the numbers)
• Jacquard loom
• (Programmable weaving machine for textile)
• 17th century mechanical calculators
• (Pascal, Leibniz and Schickard)
• 1821, Difference Engine No. 1 by Charles Babbage
• (First mechanical computer, not built until
  1991!)
• 1837, Analytical engine
• (First proposed programmable computer)
• 1853, Difference Engine by George Schentz
• (Less accurate than Babbages)

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Examples 4 continues

• Calculation
• 20th century, Alan Turing, Alonso Church, Kurt
  Gödel and Emil Post
• (Math models of computation! Free us from
  system constrains!)
• 2nd World War, Turing machine
• (Broke the Enigma code, perhaps won the war for
  the Allies)
• Christmas 1947, First transistor by Shockley,
  Bardeen and Brattain
• (First electronic transistor)
• 1965 Gordon Moores law
• (Computer speed, number of transistors and
  memory will double every 18 months)
• Moores law works extremely well until

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The Quantum Limit

• Number of bits of information/transistors cannot
  be larger than the number of atoms.
• Size of computer with certain number of
  transistors cannot be smaller than number of
  atoms used to make them.
• Clock speed of computer cannot increase
  indefinitely with present technological platform.
• Moores Law will not hold for long!!
• Need to shift our paradigm to quantum computing

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Quantum Computation

• Bits is replaced by Qubits 1gt or 0gt
• One atom is sufficient to denote one
  qubit/transistor
• Need to build the first scalable quantum
  transistor!!!
• Quantum mechanics means natural parallel
  processing
• Moores law is very easy to satisfy
• At the moment, there are more mathematics than
  physics. Quantum computers are being proposed
  for many systems. Diamond NV centres,
  Phosphorous ion in Silicon, Atom traps,
  Optical,Electrons in liquid Helium.
• QC can now factorize 15 15 3 x 5.

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Photonics _at_ the ANU
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Photonics _at_ the ANU

• Quantum Optics (Physics, Science)
• Atom Optics (Physics, Science)
• Gravitational Wave Detection (Physics, Science)
• Aerophysics and Laser Diagnostic (Physics,
  Science)
• Optical Science Centre (RSPhysSE)
• Laser Physics Centre (RSPhysSE)
• Electronic Materials Engineering (RSPhysSE)
• Telecommunication Engineering (RSISE)
• http//photonics.anu.edu.au/qoptics