Raman optical amplifier. simple presentation
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The document discusses Raman optical amplifiers, which amplify optical signals directly through a phenomenon called scattering rather than converting them to electrical signals. It distinguishes between two types of Raman amplifiers: distributed Raman amplifiers, which use the transmission fiber as the medium, and discrete Raman amplifiers, which consist of dedicated fiber and pumps. While these amplifiers have advantages such as low noise and wide gain bandwidth, they also face limitations like low gain and the necessity for high pump powers.
Raman optical amplifier. simple presentation
- 1. { Raman optical amplifiers By: Eng. Donaire Carapichoso
- 2. An Optical Fibre system in order to transmit signals overlong distances it is necessary to compensate for attenuation losses within the fibre Semiconductors devices can convert an optical signal into an electrical signal, amplify it and reconvert the signal back to an optical signal. However this procedure has several disadvantages Engineers developed what is called Optical Amplifier which amplifies the optical signal directly, without ever changing it to electrical signal. The light itself is amplified Introduction
- 3. In this presentation we will focus on Raman Optical Amplifier and Because of severe limitations such as narrow linewidth, and almost the same operation as the Raman, Brillouin fibre amplifiers will not be treated henceforth . Introduction (cont) Basic diagram of an optical amplifier
- 4. Raman Amplifier The Raman amplifier in order to amplify the optical signal it makes use of a process/phenomenum called scattering. Scattering • Raman scattering (one of the types of scattering)
- 5. In simple terms in raman scattering a molecule absorbs light, goes up to a virtual state and falls back down to a final state which is different to the inicial state. When it emits energy as it falls back down, the frequency or the energy of the light is going to be different to the incoming light. Raman scattering (Basic concepts) Consider a material which are having energy levels
- 6. Raman Scattering Stimulated Raman Scattering (The one used for Optical amplification) Spontaneous Raman Scattering Raman scattering (Basic concepts cont…)
- 7. Use stimulated Raman effect and pump laser whose frequency is equal to signal frequency plus frequency of chemical bond in the material and because it is a nonlinear process, requires very high pump powers (watts) A Raman amplifier is a device which takes input 𝜔𝑠 and amplified in the same direction or opposite direction with pump laser 𝜔𝑃. Raman amplifier (Working principal)
- 8. There are basically two types of Raman amplifiers as given here: Distributed Raman Amplifier (DRA): uses the transmission fiber itself as the medium, into which a backward pump is injected. Discrete (Lumped) Raman Amplifier (RA): The amplifier consists of a coil of dedicated fiber together with pumps. Advantages: • Low noise (3–5 dB). • Wide gain bandwidth (up to 10 nm). • Distributed amplification within the transmission fiber. Limitations: • Low gain (10 dB). • Requirement of high pump power. Types of Raman amplifier
- 9. In conclusion to this presentation we pin point the most important things concerned about the Raman Amplifier It make uses of a scattering process, to be specific Simulated Raman Scattering They are two types : Distributed Raman Amplifier (DRA Discrete (Lumped) Raman Amplifier (RA) Conclusion