Abstract: The principle of all-silicon Raman lasers for an
output wavelength of 1.3 μm is presented, which employs
quasi-phase-matched structures and resonators to enhance the output
power. 1.3-μm laser beams for GE-PONs in FTTH systems generated
from a silicon device are very important because such a silicon device
can be monolithically integrated with the silicon planar lightwave
circuits (Si PLCs) used in the GE-PONs. This reduces the device
fabrication processes and time and also optical losses at the junctions
between optical waveguides of the Si PLCs and Si laser devices
when compared with 1.3-μm III-V semiconductor lasers set on the
Si PLCs employed at present. We show that the quasi-phase-matched
Si Raman laser with resonators can produce about 174 times larger
laser power at 1.3 μm (at maximum) than that without resonators
for a Si waveguide of Raman gain 20 cm/GW and optical loss 1.2
dB/cm, pumped at power 10 mW, where the length of the waveguide
is 3 mm and its cross-section is (1.5 μm)2.
Abstract: An optical fault monitoring in FTTH-PON using ACS
is demonstrated. This device can achieve real-time fault monitoring
for protection feeder fiber. In addition, the ACS can distinguish
optical fiber fault from the transmission services to other customers
in the FTTH-PON. It is essential to use a wavelength different from
the triple-play services operating wavelengths for failure detection.
ACS is using the operating wavelength 1625 nm for monitoring and
failure detection control. Our solution works on a standard local area
network (LAN) using a specially designed hardware interfaced with a
microcontroller integrated Ethernet.
Abstract: This paper introduces a new signal denoising based on the Empirical mode decomposition (EMD) framework. The method is a fully data driven approach. Noisy signal is decomposed adaptively into oscillatory components called Intrinsic mode functions (IMFs) by means of a process called sifting. The EMD denoising involves filtering or thresholding each IMF and reconstructs the estimated signal using the processed IMFs. The EMD can be combined with a filtering approach or with nonlinear transformation. In this work the Savitzky-Golay filter and shoftthresholding are investigated. For thresholding, IMF samples are shrinked or scaled below a threshold value. The standard deviation of the noise is estimated for every IMF. The threshold is derived for the Gaussian white noise. The method is tested on simulated and real data and compared with averaging, median and wavelet approaches.
Abstract: With the drastically growth in optical communication
technology, a lossless, low-crosstalk and multifunction optical switch
is most desirable for large-scale photonic network. To realize such a
switch, we have introduced the new architecture of optical switch
that embedded many functions on single device. The asymmetrical
architecture of OXADM consists of 3 parts; selective port, add/drop
operation, and path routing. Selective port permits only the interest
wavelength pass through and acts as a filter. While add and drop
function can be implemented in second part of OXADM architecture.
The signals can then be re-routed to any output port or/and perform
an accumulation function which multiplex all signals onto single path
and then exit to any interest output port. This will be done by path
routing operation. The unique features offered by OXADM has
extended its application to Fiber to-the Home Technology (FTTH),
here the OXADM is used as a wavelength management element in
Optical Line Terminal (OLT). Each port is assigned specifically with
the operating wavelengths and with the dynamic routing management
to ensure no traffic combustion occurs in OLT.
Abstract: This paper presented a MATLAB-based system named Smart Access Network Testing, Analyzing and Database (SANTAD), purposely for in-service transmission surveillance and self restoration against fiber fault in fiber-to-the-home (FTTH) access network. The developed program will be installed with optical line terminal (OLT) at central office (CO) to monitor the status and detect any fiber fault that occurs in FTTH downwardly from CO towards residential customer locations. SANTAD is interfaced with optical time domain reflectometer (OTDR) to accumulate every network testing result to be displayed on a single computer screen for further analysis. This program will identify and present the parameters of each optical fiber line such as the line's status either in working or nonworking condition, magnitude of decreasing at each point, failure location, and other details as shown in the OTDR's screen. The failure status will be delivered to field engineers for promptly actions, meanwhile the failure line will be diverted to protection line to ensure the traffic flow continuously. This approach has a bright prospect to improve the survivability and reliability as well as increase the efficiency and monitoring capabilities in FTTH.
Abstract: This paper presented a new approach for centralized
monitoring and self-protected against fiber fault in fiber-to-the-home
(FTTH) access network by using Smart Access Network Testing,
Analyzing and Database (SANTAD). SANTAD will be installed
with optical line terminal (OLT) at central office (CO) for in-service
transmission surveillance and fiber fault localization within FTTH
with point-to-multipoint (P2MP) configuration downwardly from CO
towards customer residential locations based on the graphical user
interface (GUI) processing capabilities of MATLAB software.
SANTAD is able to detect any fiber fault as well as identify the
failure location in the network system. SANTAD enable the status of
each optical network unit (ONU) connected line is displayed onto
one screen with capability to configure the attenuation and detect the
failure simultaneously. The analysis results and information will be
delivered to the field engineer for promptly actions, meanwhile the
failure line will be diverted to protection line to ensure the traffic
flow continuously. This approach has a bright prospect to improve
the survivability and reliability as well as increase the efficiency and
monitoring capabilities in FTTH.