Relative intensity noise comparison of fiber laser and amplified spontaneous emission sources

Abstract The performance of Raman fiber laser and amplifier largely depends on the temporal stability of the pump sources. Here the relative intensity noise of three different sources are experimentally investigated and compared, which are fiber laser oscillator, master oscillator power amplifier, and amplified spontaneous emission. The amplified spontaneous emission source exhibits the lowest intensity noise. The fiber laser oscillator and amplifier have inevitable relaxation oscillation and longitudinal mode beating, which results in higher intensity noise and frequency dependent features. The results firmly explain the recent demonstrations in the performance improvement with amplified spontaneous emission as pump sources and the beneficiation of backward pumping for single frequency fiber amplifier.