What is the principle of Raman amplifier?
What is the principle of Raman amplifier?
The amplifier works on the principle of Stimulated Raman Scattering (SRS), which is a nonlinear effect. It consists of a high-power pump laser and fiber coupler (optical circulator). The amplification medium is the span fiber in a Distributed Type Raman Amplifier (DRA).
What is a Raman pump?
Raman amplification /ˈrɑːmən/ is based on the stimulated Raman scattering (SRS) phenomenon, when a lower frequency ‘signal’ photon induces the inelastic scattering of a higher-frequency ‘pump’ photon in an optical medium in the nonlinear regime.
What is the difference between EDFA and Raman amplifier?
The main difference: the amplification mechanism is different. Edfa uses the principle of stimulated radiation of EDF fiber to amplify the optical signal. Raman amplification uses the Raman effect to achieve energy conversion and amplify the optical signal.
How does a light amplifier work?
Amplification is achieved by stimulated emission of photons from dopant ions in the doped fiber. The pump laser excites ions into a higher energy from where they can decay via stimulated emission of a photon at the signal wavelength back to a lower energy level.
Why we use Raman amplifier?
The Raman amplifier makes use of stimulated Raman scattering (SRS) within the fiber, which transfers the energy of higher-frequency pump signals to lower-frequency signals. It is also common to use a WDM coupler to add up two to three pump lasers with different center frequency.
Which one is also known as lump Raman amplifier?
8. _________ is also known as lump Raman amplifiers. Explanation: Discrete Raman Amplifiers are lumped elements. This lumped element is to be inserted in transmission line to provide gain.
What does Raman measure?
Raman spectroscopy is an analytical technique where scattered light is used to measure the vibrational energy modes of a sample. Raman spectroscopy can provide both chemical and structural information, as well as the identification of substances through their characteristic Raman ‘fingerprint’.
What is the function of EDFA?
Erbium-Doped Fiber Amplifier (EDFA) is an optical amplifier used in the C-band and L-band, where loss of telecom optical fibers becomes lowest in the entire optical telecommunication wavelength bands.
Which optical amplifier is mostly used?
In optical communication the EDFA fibre amplifiers, SOA semiconductor amplifiers, or amplifiers based on the Raman effect are the most widely used ones [2–4].
What is the function of optical amplifier?
An optical amplifier amplifies light as it is without converting the optical signal to an electrical signal, and is an extremely important device that supports the long-distance optical communication networks of today. The major types of optical amplifiers include an EDFA, FRA, and SOA.
What is meant by Raman effect?
The Raman effect involves scattering of light by molecules of gases, liquids, or solids. The Raman effect consists of the appearance of extra spectral lines near the wavelength of the incident light. The Raman lines in the scattered light are weaker than the light at the original wavelength.
How does a distributed type Raman amplifier work?
The amplifier works on the principle of Stimulated Raman Scattering (SRS), which is a nonlinear effect. It consists of a high-power pump laser and fiber coupler (optical circulator). The amplification medium is the span fiber in a Distributed Type Raman Amplifier (DRA).
How are pump lasers used in Raman amplification?
This amplifier requires much higher power than the EDFA. In practice, a Raman amplifier uses multiple pump lasers to realize high gain and flatness. Using a polarization multiplexer, two pump lasers with the same center frequency can be used to double pump power and reduce the polarization dependency of Raman gain.
How is the Raman amplification different from the EDFA?
Raman amplification is an alternative amplification technology and has been increasingly implemented in long-haul system. The Raman amplifier is different from the EDFA in that it is a distributed amplification system. Figure 15.4 shows a schematic of the Raman amplifier and power profile along the transmission line.
How big is the peak of Raman amplification?
This spectrum exhibits a peak for a 13.2-THz frequency shift in the case of Si-Ge glass with a top width of around 10-nm width. It represents the likelihood of interaction of pump power with the fiber glass.