Transcript Photonic Devices - Bragg gratings Reflectivity (%) Peak shifts with temperature and / or strain Reflectivity (%) Theory Experiment Victoria University 1430 Optical Technology Research Laboratory Wavelength (nm) This graph shows typical.

Photonic Devices - Bragg gratings
100
Reflectivity (%)
Peak shifts with
temperature and / or strain
Reflectivity (%)
80
60
40
Theory
Experiment
Victoria University
20
0
1430
Optical Technology
Research Laboratory
1435
Wavelength (nm)
1440
1445
This graph shows typical experimental & theoretical Grating reflection
spectra. The peak wavelength is sensitive to changes in temperature
(0.01nm/ degree C) as well as changes in strain (0.001 nm if the fibre
stretches by 1 part in 106), making Bragg gratings useful in fibre sensors.
Special fibres for special applications
Current sensing
on HV powerlines
Erbium-doped fibre amplifier for all-optical
repeaters in long haul communication links
“Non-zero dispersion-shifted fibre”
for long haul high bit rate links
Optical fibre
wound around
conductor can
safely sense
magnetic fields
Planar optical waveguides
Planar waveguides written
into a polymer on a silicon
wafer using a focused laser
Microscope photo of a
planar waveguide device
Planar Optical Waveguides
Planar waveguides can
also be built up layer by
layer, as has been done
for silicon chips
Sequence of processing
steps:
• Cladding deposition
• Core deposition
• Masking
• Etching
• Cladding deposition
This allows quite complex
waveguide structures to
be fabricated over a large
area in a short time
Microscope photo of
a buried channel
waveguide showing
the ~ 6 micron core
(bright) against a
darker cladding
Microphotonics - a new frontier
Micro-electro-mechanical systems (MEMS)
In recent years, new kinds of moving objects such as tiny motors, pumps and
moving mirrors have been fabricated on micrometer scales. This tiny
electronically tiltable mirror is a building block in devices such as all-optical
cross-connects and new types of computer data projectors.
MEMS array configured as an optical crossconnect