EDFA amplifier ppt

This topic is related to optical fiber communication.

1. Seminar Topic On EDFAs: Architecture ,working & Types Presented to: presented by : Dr. BC Choudhary sachin maithani Dr. balwinder raj m.e. (regular) ( ece )

2. Table of content 1. Introduction 2. Block diagram of EDFA 3. Why E rbium? 4. Amplification Mechanism 5. LOSS-GA IN Characteristi c s 6. Maximum possible gain 7. I nput- Output Characteristics 8. 980 nm vs 1 440 nm pumping EDFAs 9.How does an EDFAs Work? 10. Types of EDFAs 11. EDFA Optical Amplifier—Boosting Optical Signals More Effectively 12. Three EDFA Amplifier Types for DWDM Connectivity 13. Advantages OF EDFA 14. Drawbacks of EDFAs 15. Applications of EDFA 16. . Summary 17.Refrences

3. Introduction

4. Block diagram of EDFA EDFA s consist of erbium-doped fiber having a silica glass host core doped with active Er ions as the gain medium. Erbium-doped fiber is usually pumped by semiconductor lasers at 980 nm or 1480 nm

5. Why Erbium? Erbium has several important properties that make it an excellent choice for an optical amplifier Erbium ions (Er3+) have quantum levels that allows them to be stimulated to emit in the 1550 nm band, which is the band that has the least power loss in most silica-based fiber. Erbium's quantum levels also allow it to be excited by a signal at either 980nm or1480nm, both of which silica-based fiber can carry without great losses

6. AMPLIFICATION MECHANISM

7. AMPLIFICATION MECHANISM Step 1: T h e possible pump wavele n gt h s are 9 80 & 1 4 8 nm I n n ormal operatio n , a pump laser emitti n g 9 8 - nm p h oto n s is u sed to excite io n s from t h e grou n d state to t h e pump level, as sh own by transition process. Step 2: Durin g t his d ecay , th e excess energy is released as phonon s or , equivalently, mechanical vibrations in t h e fiber Within th e metastable ba nd , t h e electrons of t h e excited io n s te n d to pop u l ate the lower end of the ban d .

8. AMPLIFICATION MECHANISM Step 3: Another possible pump wavelength is 1480 nm. The energy of these pump photons is very similar to the signal-photon energy , but s lightly higher . Step 4: Some of the ions sitting at the metastable level can decay back to the ground state in the absence of an externally stimulating photon flux, as shown by transition process. This-decay phenomenon is known as s pontaneous emission and adds to the amplifier noise .

9. AMPLIFICATION MECHANISM Step 5 & 6: Two more types of transitions occur when a flux of signal photons that have energies corresponding to the band gap energy between the ground state and the metastable level passes through the device. First, a small portion of the external photons will be absorbed by ions in the ground state St ep 7: stimulated emission process a signal photon triggers an excited ion to drop to the ground state , thereby emitting new photon of the same energy , wavevector and polarization as the incoming signal photon.

10. LO S S- G A I N C h a r a cter i sti c s

11. Max i mum possib l e g a i n

12. I nput- Output Characteristics

13. 980 nm vs 1480 nm pumping EDFA

14. How Does an EDFA Work?

15. How Does an EDFA Work? The basic structure of an EDFA consists of a length of Erbium-doped fiber (EDF), a pump laser, and a WDM combiner. The WDM combiner is for combining the signal and pump wavelength so that they can propagate simultaneously through the EDF. The optical signal, such as a 1550nm signal, enters an EDFA amplifier from the input. The 1550nm signal is combined with a 980nm pump laser with a WDM device. The signal and the pump laser pass through a length of fiber doped with Erbium ions. As we talked above, EDFA uses the erbium-doped fiber as an optical amplification medium. The 1550nm signal is amplified through interaction with the doping Erbium ions. This action amplifies a weak optical signal to a higher power, effecting a boost in the signal strength.

16. EDFA types: EDFA amplifiers are of three types based on their purpose: Optical Boost Amplifier (OBA) Optical Pre Amplifier (OPA) Optical Line Amplifier (OLA)

17. Optical Boost Amplifier (OBA) The optical boost amplifier is placed just after the transmitter. It amplifies the multiplexed optical signals before sending into optical fiber. Features of OBA High input power High output power Medium optical gain

18. Optical Pre Amplifier (OPA) The optical pre-amplifier is placed just before the receiver, such that sufficient optical power will be received by the receiver. OPA is designed for optical amplification to compensate for losses in a de-multiplexer located near the receiver. Features of OPA Medium to low input power Medium output power Medium optical gain

19. Optical Line Amplifier (OLA) or in-line amplifier The optical line amplifier is placed in the middle of the transmission line. It compensates the optical signal loss caused by the optical fiber. The typical distance between each of the OLA is 40 km, 60km, 80km, or 100km, depends on the requirement. OLA is designed for optical amplification between two network nodes on the main optical link. Features of OLA Medium to low input power High output power High optical gain

20. EDFA Optical Amplifier—Boosting Optical Signals More Effectively

21. Three EDFA Amplifier Types for DWDM Connectivity

22. Advantages OF EDFA EDFA has high pump power utilization (>50%). EDFA directly and simultaneously amplifies a wide wavelength band (>80nm) in the 1550nm region, with a relatively flat gain. Flatness can be improved by gain-flattening optical filters. Gain in excess of 50 db . EDFA features low noise figure suitable for long haul applications. EDFA deployment is relatively easier to realize and more affordable compared with other signal amplification methods.

23. Drawbacks of EDFA The size of EDFA amplifier is not small. Unlike SOA and Ramen amplifier, EDFA, with a typical size of ten meters long, is difficult to integrate with other semiconductor devices. Since dropping channels can give rise to errors in surviving channels, dynamic control of amplifiers is necessary.

24. Applications of EDFA Dense Wavelength Division Multiplexing (DWDM)  

25. . Summary As EDFA performs as the most widely used optical amplifier, EDFA technology proves to be the most advanced one that holds the dominant position in the market. With the deployment of WDM systems and the increasing aggregate bandwidth of optical fibers, WDM system integrated with EDFA will gain more benefits.

26. References 1.Wikipedia 2. https://ieeexplore.ieee.org/document/9105942 3. https://www.physics-and-radio-electronics.com/blog/edfa-erbium-doped-fiber-amplifier/