title: Coherent addition of fiber-amplified ultrashort laser pulses.
abstract: We report on a novel approach of performance scaling of ultra-fast lasers by means of coherent combination. Pulses from a single mode-locked laser are distributed to a number of spatially separated fiber amplifiers and coherently combined after amplification. Splitting and combination is achieved by polarization cubes, i.e. the approach bases on polarization combining. A Hänsch-Couillaud detector measures the polarization state at the output. The error signal (deviation from linear polarization) is used to stabilize the synchronization of different channels. In a proof-of-principle experiment the combination of two femtosecond fiber-based CPA systems is presented. A combining efficiency as high as 97% has been achieved. The technique offers a unique scaling potential and can be applied to all ultrafast amplification schemes independent of the architecture of the gain medium.
authors.affiliation: Institute of Applied Physics, Friedrich-Schiller-University Jena, Jena, Germany. enrico.seise@uni-jena.de
authors.forename: Enrico
authors.initials: E
authors.lastname: Seise
authors.forename: Arno
authors.initials: A
authors.lastname: Klenke
authors.forename: Jens
authors.initials: J
authors.lastname: Limpert
authors.forename: Andreas
authors.initials: A
authors.lastname: Tünnermann
mesh_terms: D000669:Amplifiers, Electronic; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007368:Interferometry / Q000295:instrumentation*; D007834:Lasers