Modulation characteristics of a three-section master oscillator power amplifier at 1.5 μm

Resumen

Direct optical modulation of a 1.55 ?m three-section Master Oscillator Power Amplifier has been demonstrated. The temporal response, the optical spectra and the optical modulation amplitude have been analyzed as a function of the frequency and the modulating amplitude. For low modulation amplitude, no spectral broadening was observed up to 1.5 GHz. However, at 12.5 MHz an optical broadening of ~ 4 pm was observed for high modulation amplitudes. At this frequency an extinction ratio of 42 dB has been achieved. The modulation amplitude degrades for frequency values higher than 30 MHz. The device performance under modulation at 12.5 MHz is interesting for its application as laser source for CO2 detection by differential absorption LIDAR operating in the Continuous Wave Random Modulation mode.