1. Light

2. Questions ??? What is light? What is light? Why can we see objects in the presence of light? Why can we see objects in the presence of light? How fast does light travel? How fast does light travel? What are the applications of light in our daily life? What are the applications of light in our daily life? video videovideo

3. History of Optics Geometrical Optics (study the behaviour of light using Geometry) by Euclid in Catoptrics, 300B.C. Geometrical Optics (study the behaviour of light using Geometry) by Euclid in Catoptrics, 300B.C. End of 17 th Century: Light as a wave to explain reflection and refraction, by Christian Huygens End of 17 th Century: Light as a wave to explain reflection and refraction, by Christian Huygens 1704: Light as moving particles to explain its behaviour, by Issac Newton 1704: Light as moving particles to explain its behaviour, by Issac Newton 1864: Light as electromagnetic wave by Maxwell 1864: Light as electromagnetic wave by Maxwell 20 th Century: Quantum theory (light as photon) 20 th Century: Quantum theory (light as photon)

4. How Fast does light travel ? Early Attempt Early Attempt Galileo Galilei proposed an “lantern” experiment in 1638 Galileo Galilei proposed an “lantern” experiment in 1638 Experiment carried out by the Accademia del Cimento of Florence in 1667  No Conclusive Result Experiment carried out by the Accademia del Cimento of Florence in 1667  No Conclusive Result First estimate of light is made in 1676 by Ole Christensen Rømer by studying the motion of Jupitor’s moon. First estimate of light is made in 1676 by Ole Christensen Rømer by studying the motion of Jupitor’s moon. Light travels at a speed of 300000000 m/s in vacuum. Light travels at a speed of 300000000 m/s in vacuum.

5. Photonics What is photonics? What is photonics? Photonics is the practical application of light and optics. Photonics is the practical application of light and optics. It integrates lasers, optics and electronics to develop applications in industries It integrates lasers, optics and electronics to develop applications in industries Application: telecommunications, information technology, entertainment and displays, lighting, consumer products, precision manufacturing, biology and medicine, environmental sensing, homeland security and defense, astronomy and aerospace, and research. Application: telecommunications, information technology, entertainment and displays, lighting, consumer products, precision manufacturing, biology and medicine, environmental sensing, homeland security and defense, astronomy and aerospace, and research. http://www.lasertechonline.org/Educator_course/overview.htm http://www.lasertechonline.org/Educator_course/overview.htm

6. Overview of Photonics The term “photonics” is coined in analogy with “electronics”. The term “photonics” is coined in analogy with “electronics”. Electronics involves the control of electron charges. Electronics involves the control of electron charges. Photonics involves the control of photons. Photonics involves the control of photons. It reflects the growing tie between optics and electronics with the increasing role of electronics devices in optical systems. It reflects the growing tie between optics and electronics with the increasing role of electronics devices in optical systems.

7. Overview of photonics Light emission Light emission Transmission Transmission Deflection: Reflection, Refraction, Diffraction, Interference Deflection: Reflection, Refraction, Diffraction, Interference Amplification and detection Amplification and detection

8. Major Developments Invention of the Laser in 1960s Invention of the Laser in 1960s Fabrication of low loss optical fibers Fabrication of low loss optical fibers Introduction of semiconductor devices Introduction of semiconductor devices

9. Application of photonics Information technology and telecommunication Information technology and telecommunication Information transportation, processing, storage etc. Information transportation, processing, storage etc. Optical fiber for communications is being installed at the rate of 1000 meters per second. Optical fiber for communications is being installed at the rate of 1000 meters per second. To meet the needs of computing and communication in the next 10 to 20 years, many capacities have to hundredfold. To meet the needs of computing and communication in the next 10 to 20 years, many capacities have to hundredfold.

10. Application of photonics Health care and life sciences Health care and life sciences A wide variety of new therapies, e.g. laser heart surgery A wide variety of new therapies, e.g. laser heart surgery Non-invasive diagnosis and monitoring Non-invasive diagnosis and monitoring New biological research tools for visualisation, measurement, analysis and manipulation, e.g. use of laser in DNA sequencing. New biological research tools for visualisation, measurement, analysis and manipulation, e.g. use of laser in DNA sequencing.

11. Application of Photonics Manufacturing Manufacturing Low-cost lasers and laser imaging system Low-cost lasers and laser imaging system Use of Optics in various industry such as semiconductor, construction and chemical production, e.g. semiconductor chips are manufactured by optical lithography. Use of Optics in various industry such as semiconductor, construction and chemical production, e.g. semiconductor chips are manufactured by optical lithography. Making optical equipment for manufacturing itself is a $1 billion industry, and it supports the $200 billions electronics industry. Making optical equipment for manufacturing itself is a $1 billion industry, and it supports the $200 billions electronics industry.

12. Application of photonics Manufacturing of optical systems and components Manufacturing of optical systems and components Changes in the design of optical systems and components to meet the needs in different industries Changes in the design of optical systems and components to meet the needs in different industries Better understanding of optical materials such as glass, polymers and metals. Better understanding of optical materials such as glass, polymers and metals.

13. Application of photonics Optical sensing, lighting and energy Optical sensing, lighting and energy Optical sensor, revealing information that cannot be seen by human eyes Optical sensor, revealing information that cannot be seen by human eyes Lighting system, reducing the electricity consumption Lighting system, reducing the electricity consumption Solar energy (photovoltaic cell) Solar energy (photovoltaic cell)

14. Application of photonics Military and surveillance Military and surveillance Satellite surveillance Satellite surveillance Night vision imagers Night vision imagers Lasers for targeting and navigation Lasers for targeting and navigation

15. The future of photonics Extensive high-speed fiberoptic communications network around the world Extensive high-speed fiberoptic communications network around the world New non-invasive way of health monitoring, diagnosis and treatment New non-invasive way of health monitoring, diagnosis and treatment Highly efficient lighting system and solar cells Highly efficient lighting system and solar cells More efficient manufacturing control and processing More efficient manufacturing control and processing

16. What have you learnt in this lesson?