الفهرس 
GENERAL INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Internet is growing at a very fast rate. So, its demand for network capacity is huge. All optical
networks are the only way to cater to this rising demand. Many studies have focused on the
optical networks switching and routing. On the other hand, insufficient research is done
paying attention for the optical devices, sub-systems and systems.
In this thesis, we elaborate on earlier trends to propose some new optical networks sub-
systems based on fiber Bragg grating (FBG). We demonstrate a silica-based tunable fiber
Bragg grating (TFBG) filter with a wavelength tuning range over 60 1U11. A magnetically
TFBG package is employed to obtain a wide wavelength tuning range from 1540 to 1602 lUll
which covers the entire C band and most of the L-band. The TFBG is achieved by varying an
input current to a solenoid, resulting in an electromagnetic force, which is used as a strain
(tension and compression) on the FBG. This approach is fast, has a broad band of tuning
wavelengths and achieves a power reduction as no continuous supply of power is needed to
maintain the set shift, due to the latch system used.
Also, a new optical buffer is presented with a better utilization, a better delay accuracy and a
shorter fiber length. In addition, a combination of two devices optical cross connect (OXC)
and optical add/DROP multiplexer (OADM) into a single device called optical cross add DROP
multiplexer (OXADM) is shown to give better crosstalk isolation levels around 30 dB when
compared with the use of each device alone. Different techniques are shown to further
enhance the OXADM isolation crosstalk level (lower crosstalk) leading to 65 dB. The first
one is to redesign the OXADM to get a better result. The second solution is to change the
parameters of the TFBG. Also, a multistage is shown making some sort of buffering for the
wavelengths, which we name as signal parking. So, this multistage OXADM can be used as
optical buffer. Finally, another upgrade of the OXADM is shown to get a bi-direction device.
This allows the same switching performance in both directions. Furthermore an NxN
OXADM is proposed.