Impact of spectral phase mismatch on femtosecond coherent beam combining systems

Louis Daniault (1) , Marc Hanna (1) , Laurent Lombard (2) , Yoann Zaouter (3) , Eric Mottay (3) , Didier Goular (2) , Pierre Bourdon (2) , Frédéric Druon (1) , Patrick Georges (1)

1 Laboratoire Charles Fabry / Lasers
2 ONERA - The French Aerospace Lab [Châtillon]
3 Amplitude Systèmes

We experimentally investigate the impact of spectral phase mismatch on the coherent beam combining of two femtosecond fiber chirped-pulse amplifiers. By measuring the differential spectral phase, both linear and nonlinear contributions are identified. An accumulated nonlinear phase as high as 6 rad has been measured, for which a combination efficiency of 91% can be obtained by symmetrizing the pump and injection powers. This also allows us to quantitatively separate the spatial and temporal contributions of the nonperfect combining efficiency.

Domaines: Optique [physics.optics]

Louis Daniault, Marc Hanna, Laurent Lombard, Yoann Zaouter, Eric Mottay, et al.. Impact of spectral phase mismatch on femtosecond coherent beam combining systems. Optics Letters, 2012, 37 (4), pp.650-652. ⟨hal-00702163⟩