This optical amplification is started from some emission...

This optical amplification is started from some emission but it is not exposed yet until Albert Einstein proposed in 1916. After that, the things became more seriously after 1954 when Townes and Arthur Schawlow also with Gordon Gould proposed laser action, then not long after 4 years, in 1960, first laser was build by Theodore Maiman. Besides that, Gordon also derived the word laser from â€Å"light amplification by the stimulated emission of radiation†. The laser developer look amplification is very important as a step to build a laser, so these people make one advance to develop amplifiers from semiconductor laser to be used as light sources. This is because of semiconductor have high gain. Laser made up with high gain and low noise is†¦show more content†¦This is because maybe due to this erbium doped fiber amplifiers can amplify signals at the low loss. This type also is suitable to be use in long-haul and have low noise. Besides that, it also have wide spectral b and amplification and it is manly useful for WDM application and it’s have relative flat gain ( 20 dB). In contrast, there are some disadvantage using this type which is includes it is not easily integrated with other devices because it is relatively large device (km length of fiber). Diagram 3 : A Erbium doped fiber Amplifier The Optical gain in Optical amplifier can be defined as the ratio of the optical signal power at the input to the optical signal power at the output. This can de also shown by the formula ;, G = Pin Pout The gain is basically measured in dB and exist in the range of the 10 until 30 dB. Noise figure is the measure of the signal-to- noise ratio between input and output of the component. In other words, Noise Figure (NF) . It is a measure of how much a devices such as amplifier degrades the signal to noise ratio (SNR). During amplification process, noise exist, so the output signal is always noisier from input signal. So, in order to get better performance of optical amplifier, Noise figure should be kept as low as possible. Noise Figure , [dB] = 10 log10 (SNRin