Wavelength Division Multiplexing
Jigisha patel, Nirma University, Richa Gandhi,Nirma University.
WDM,Wavelength division multiplexing optical module using a planar lightwave circuit for full duplex operation,
. The module cost is lower than that of conventional optical modules because we have integrated its optical functions and simplified its assembly.
II. MULTIPLEXING AND DEMULTIPLEXING
computing. Since a
Fig 1. The diagram for the structure of the Littrow type WDM.
If we put two layers of fiber arrays, the devices can transmit WDM signal in
Fig 2 Scheme of
Fig. 3 shows the single fiber
Fig. 3. ATM passive double star system configuration.
Fig. 4. Full duplex 1.3/1.55 micrometer WDM optical module configuration with PLC platform
IV. CROSS TALK IN FULL
To fabricate an optical module with the above configuration, we first determined the
Fig 5 Relationship between
The optical crosstalk was effectively suppressed by the WDM filter and was less than
filter while it was eliminated at greater distances.
The waveguide grating couplers described in this letter consist of a grating structure where the grating lines are arranged in a complicated manner determined by the design method. The freedom in choosing the local position of the grating lines makes it possible to impose a
modulation onto the incoupled light. This can be used to obtain a grating structure that in addition to coupling light into the waveguide performs functions such as focusing, beam splitting, and wavelength demultiplexing of the incoupled light. The design algorithm aims at optimizing the local position of each grating line so that as much light as possible of each wavelength is focused into the desired position. Two mechanisms are responsible for the wavelength discriminating capability of the grating coupler: First, the incident wave, which is a spherical wave emitted from the tip of the fiber, has a phase that varies over the grating area where the variation depends on the wavelength. Second, the optical path length in the waveguide is different simply because the vacuum wavelength is different and, to a lesser extent, because of the small change in the effective refractive index of the waveguide mode for the different wavelengths (waveguide and material dispersion). There is also a third mechanism contributing to the wavelength sensitivity: the local interaction between the optical field and the grating structure that determines the coupling strength. However, this effect was not taken into account because of the relatively small wavelength separation used. An accurate description of this interaction requires rigorous electromagnetic modeling using, e.g., the finite difference time domain method (FDTD). The coupler design was carried out using an efficient optimization algorithm. The computer code was written in MATLAB and the calculation time on a
A fiber optic system designed to transmit over a single optical fiber asynchronous signals previously carried by up to 48 separate metallic cables was developed as a test bed for aircraft applications of fiber optics. Advanced
In this letter we discussed the implementation of WDM using the systems described above. These systems efficiently multiplexes and demultiplexes different wavelengths used in telecommunication networks, and we also discussed full duplex system in which bidirectional link can be established.
Kurosaki, Masahiro Yanagisawa, Yasuhiro Suzuki, Member, IEEE, Yuji Akahori, Yasuyuki Inoue, Member, IEEE, Yuichi Tohmori, Member, IEEE, Kazutoshi Kato, Member, IEEE, Yasufumi Yamada, Noboru Ishihara, and Kuniharu Kato, Member, IEEE.
Wavelength division multiplexers/demultiplexers for highthroughput optical links The University of Texas at Austin, PRC, MER 1606H, 10100 Burnet Road
Applications of wavelength- division multiplexing and time-
division multiplexing to aircraft data links by garry duck,Canada.