Title: Refraction and Optical Fibres
1Refraction and Optical Fibres
Dr Murray Thompson University Senior
College Murray.thompson_at_adelaide.edu.au
Prof Tanya Monro Centre of Expertise in
Photonicstanya.monro_at_adelaide.edu.au
2Refraction and Optical Fibres
- This material has been developed as a part of
the Australian School Innovation in Science,
Technology and Mathematics Project funded by the
Australian Government Department of Education,
Science and Training as a part of the Boosting
Innovation in Science, Technology and Mathematics
Teaching (BISTMT) Programme.
3Refraction and Optical Fibres
- When light travels from one medium to another it
changes speed. - It also changes direction.
4Refraction
- From a fast medium to a slow medium, the light
bends towards the normal.
5Refraction
- From a slow medium to a fast medium, the light
bends away from the normal.
6Snells Law of Refraction
which is the refractive index from medium 1 to
medium 2.
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9Total Internal Reflection
- When the light goes from slow to fast, as the
angle of incidence is increased, the angle of
refraction increases as well, until it reaches
90?. - The angle of incidence when this happens is
called the critical angle.
10Total Internal Reflection Critical Angle
11Total Internal Reflection
- Beyond the critical angle, no refraction is
possible and the light is said to totally
internally reflect.
12Total Internal Reflection
- No refraction is possible beyond the critical
angle.
13Below the critical angle
14At the critical angle
Note the reflected ray
Note the refracted ray at grazing angle
colour dispersion
15Beyond the critical angle Total internal
reflection.
16Total Internal Reflection
Snells law
17Guiding Light
- Need to guide light to communicate optically
between points - First observation of light guiding made by John
Tyndall - Based on total internal reflection
18Photonics is Everywhere
Photonics is the science of the photon, the
fundamental particle of light.
Compact tunable lasers for optical
telecommunications
Optical fibres for structural strain sensing
Sea mice use photonic crystal effects to warn off
predators
19Optical Fibres Beyond Telecommunications
- Optical fibres can also have applications in
- Medicine
- Biological and genetics research
- Defence
- Industrial materials processing
- Chemical and pollution sensing
- Next generation lasers
- Optical data processing
- Transmitting light beyond the near-IR
- And so new types of optical fibres are needed
20Microstructured Optical Fibres
fibres with micron-scale transverse features
21Why Microstructure?
- Engineering materials on the scale of the
wavelength of light can lead to materials with
new optical properties - Using air as the cladding of an optical fibre
means that fibres can be made from a single
material - Light can be used to probe the properties of
materials located within the air holes - Here at Adelaide University, we are setting up
facilities to develop a whole new class of
optical fibres soft glass microstructured
optical fibres
22Overview of Fibre Activities at Adelaide
University
23Extrusion
glass billet
OD29mm h34mm
Stainless steel die
Structured glass preform
24Extrusion Preform Variety
- Structured preforms in one step
- Flexible geometry
- Geometric reproducibility
- Successfully applied to lead silicates,
tellurites, chalcogenides, bismuthates, lead
germanates
25Careers in Photonics
Centre of Expertise in PhotonicsSchool of
Chemistry PhysicsUniversity of
Adelaide Professor Tanya Monro Director
www.chemphys.adelaide.edu.au/physics/research/phot
onics
26Science Degrees at Adelaide University
- Bachelor of Science (BSc)
- - Biomedical sciences
- - Biophysics
- - Chemistry
- - Environmental biology and Ecology
- - Geosciences (Geology and Geophysics)
- - Molecular biology and Biotechnology
- - Physics
- - Psychology and Behavioural Sciences
27A Science Degree Provides
- Scientific knowledge
- Technical skills
- Problem solving skills
- Analytical skills
- Critical thinking
- Communication skills
- Initiative
- Teamwork
- Time management
- Responsibility
- Confidence
And Leads to a Career in
- Government
- Health
- Education
- Private industry
- Consultants
- Research laboratories
- Own business
28Pre-requisites
- BSc
- Two science subjects, one chosen from
- Chemistry, Maths Studies, Specialist Maths,
Physics - one from
- Biology, Chemistry, Geology, Physics
- Specialist Programs with Physics
- Physics,
- Maths Studies and
- Specialist Maths
29BSc (Optics and Photonics)
- Optics and Photonics is a steadily growing sector
in industry - Australian tertiary institutions are not
producing enough trained people - (even allowing for the bust in the boom/bust
cycle ! ) - Physics graduates are readily employable in this
industry - Named degree makes qualification more
recognisable - Adelaide is rapidly developing strength in
defence photonics (potential employers include
DSTO, Tenix, BAE systems - Wide range of other opportunities including in
medicine (eg ophthalmology), communications, etc - Attractive career opportunities with scope for
creativity and practical relevance
30Job opportunities in photonics
- There are opportunities for people with photonics
training in Academia, Industry, Defence - Requires study of physics and mathematics
- Bachelor of Science (Optics and Photonics)