Contents I. Introduction
Ultrahigh-Capacity optical transmission systems are a vital component for 21st-century telecommunications networks that support various expanding information systems such as the Internet, mobile communications, and digital cable television [1]. Wavelength-division-multiplexing (WDM) systems employing optical amplifiers such as the erbium-doped fiber amplifier (EDFA) are considered the most effective solution to increase data transmission capacity [2]–[4]. The main characteristics of EDFAs are their gain and noise figure, and their values depend on the input signal wavelength, input signal power, and pump power [5]. The gain is determined by measuring the difference between the output signal power and the input signal power, whereas the noise figure is calculated from the gain, amplified spontaneous emission (ASE), and resolution of the optical spectrum analyzer (OSA). The accurate ASE level is measured using the interpolation technique, and thus, even a slight error in the initial measurement of the input power level will cause a cascading effect that will render the final ASE measurement invalid. In addition, the accuracy of the gain value is also dependent on the accuracy of the input measurement. This makes the current manual measurement techniques not suitable for gain value measurement as even the slightest deviation in the initial input measurement will result in inaccurate gain values. As such, using manual measurement techniques for depressed cladding erbium-doped fiber (EDF) experiments could lead to inaccurate results and long experiment times.
