Need of Optical Switching Devices

NEED OF OPTICAL SWITCHING DEVICES:-[pic 1]

The interest the optics community has in these devices has spawned from the fact that conventional computational speeds are approaching limits. All-optical logic devices are vital elements in ultra-high speed optical signal processing, which must have compatibility with large bandwidth of optical fiber. Presently for such compatibility the dense WDM system along with E-O-E conversion is used. Both of these functions require large power consumption. Besides this the power consumption increases as the number of wavelengths in WDM system increases. The present day technology of VLSI circuits is reaching to their miniaturization limit. These problems can be overcome by use of all optical signal processing. As such, all optical logic gates and particularly universal logic gate (NAND and NOR) are very important to support various necessary optical switching and processing functions.

Optical computing has many advantages over electronic computing.

 Some of them are:-

• Immunity to electronic interference

• Lighter, more compact systems

• Immunity to short circuits

• Lower-loss transmission

• Significantly more bandwidth

• Easier/cheaper parallel computing

Software used :- optisystem 7.0

Various Components used in simulations are:-

CW LASER:- it generates the continuous wave optical signal of the desired frequency.

USER DEFINED BIT SEQUENCE GENERATOR:-it generates the bit sequence as defined by user and gives output in the binary.

OPTICAL GAUSSIAN PULSE GENERATOR:-it generates a Gaussian pulsed optical signal according to the bit sequence at the output.

TRAVELING WAVE SOA:- it performs lumped amplification with traveling wave semiconductor optical amplifiers (SOA).it is mainly applicable to describe the amplification of CW and optical pulse signals. The pulse widths have to be much larger than the intraband relaxation time that governs the dynamics of the induced polarization. Typically, the intraband relaxation time is 0.1 ps. Therefore, the model can be used for pulse widths larger than 1 ps.

WDM MUX:-it filters the various input signals by an optical filter and combines them into in one signal. The Optical filter can be a Rectangle, Gaussian, or Bessel optical filter.

WDM DEMUX: The input signal is split into various signals that are filtered by an optical filter. The optical filter can be a Rectangle, Gaussian, or Bessel optical filter.

RECTANGLE OPTICAL FILTER:- it is a filter with rectangular transfer function

i.e. H(f)=[pic 2]

where αis the parameter Insertion loss, d is the parameter Depth, fcis the filter center frequency defined by the parameter Frequency, B is the parameter Bandwidth, and f is the frequency.