Erbium-doped fiber amplifiers:
- The active medium in an optical fiber amplifier consists of a nominally 10 to 30 m length of optical fiber that has been tightly doped with a rare-earth element such as Erbium (), Ytterbium (), Neodymium () or Praseodymium (). The host fiber material can be either standard silica, a fluoride-based glass or a multicomponent glass.
- The operating regions of these devices depends on the host material and the doping Flourozirconate glasses doped with or are used for operation in the 1300-nm window, since neither of these ions can amplify 1300 nm signals when embedded in silica glass.
- The most popular material for long haul telecommunication application is a silica fiber doped with Erbium, which is known as Erbium-doped fiber amplifier or EDFA.
- The operation of an EDFA by itself normally is limited to the 1530 to 1560 nm region.
Features of EDFA
- Active medium is created by erbium (), ytterbium (), neodymium (), praseodymium( ).
- DFA can pump device at several different
- Low coupling
- Constant
∵
Example 8.3.1 :An EDFA amplifier produces = 27 dBm for an in out level of 2 dBm at 1542 nm.
- Find the amplifier
- What is the minimum pump power required ? [Jan./Feb.-2007, 10 Marks] Solution : i) Amplifier gain
… Ans
- ii) Pump power Pp, in
∵
Therefore minimum pump power should be 27 dBm. … Ans