What is chromatic dispersion?

Chromatic dispersion is the term given to the phenomenon by which different spectral components of a pulse travel at different velocities. To understand the effect of chromatic dispersion, we must understand the significance of the propagation constant β.

What are the two types of chromatic dispersion?

Normal and Anomalous Dispersion Anomalous dispersion sometimes occurs at longer wavelengths, e.g. in silica (the basis of most optical fibers) for wavelengths longer than the zero-dispersion wavelength of ≈ 1.3 μm. in units of picoseconds per nanometer and kilometer (ps/(nm km)).

What is the difference between modal and chromatic dispersion?

Modal and chromatic dispersion are important in describing the optical properties of optical fibers. The key difference between modal and chromatic dispersion is that modal dispersion can occur with a monochromatic light source whereas chromatic dispersion cannot occur with a monochromatic light source.

What causes chromatic dispersion?

Chromatic dispersion (CD) is caused by the fact that singlemode glass fibers transmit light of different wavelengths at different speeds. The ratio of the speed of light in a medium to the speed in a vacuum defines the index of refraction or refractive index of the material.

What is chromatic dispersion test?

Chromatic dispersion analyzers measure the total chromatic dispersion of the fiber as a function of wavelength, which also includes the CD slope. With these parameters, the CD test set calculates a Lambda-Zero—the wavelength where no dispersion occurs.

How can chromatic dispersion be reduced?

One way to decrease chromatic dispersion is to narrow the spectral width of the transmitter. Lasers, for example, have a more narrow spectral width than LEDs. A monochromatic laser emits only one wavelength and therefore, does not contribute to chromatic dispersion.

What are the different types of dispersion in optical fiber?

Dispersion in Optical Fibers. There are three types of dispersion: modal, chromatic, and material.

What are two types of dispersions?

In data transmission systems, five types of dispersion can occur:

  • Modal dispersion.
  • Chromatic dispersion.
  • Material dispersion.
  • Waveguide dispersion.
  • Polarization Mode Dispersion.

How is chromatic dispersion measured?

There are three methods to determine chromatic dispersion – pulse, phase shift, and optical time domain reflectometry (OTDR). The pulse method measures differential delay between optical pulses of various wavelengths, using a multiple wavelength transmitter at one end of the fiber and a receiver at the other end.

How do you compensate chromatic dispersion?

Chirped fiber Bragg grating can also be used, where different wavelengths are reflected at different positions in the grating so as to compensate the dispersion caused by transmission. It is capable of compensating a given amount of dispersion with a much shorter length when compared to DCF.

What are the two types of dispersion?

There are five types of dispersion:

  • Modal dispersion.
  • Material dispersion.
  • Waveguide dispersion.
  • Chromatic dispersion.
  • Polarization mode dispersion.

What are the two main types of dispersion and define each?

There are two main types of dispersion methods in statistics which are:

  • Absolute Measure of Dispersion.
  • Relative Measure of Dispersion.