Yb3+-doped rod-type amplifiers with local adiabatic tapers for peak power scaling and beam quality improvement. (18th September 2017)

• Record Type: Journal Article
• Authors: Zhu, Yuan; Eschrich, Tina; Leich, Martin; Grimm, Stephan; Kobelke, Jens; Lorenz, Martin; Bartelt, Hartmut; Jäger, Matthias
• Is Part Of: Laser physics. Volume 27:Number 10(2017:Oct.)
• Publication Date: 2017-09-18
• Subjects: large-core fiber -- local adiabatic taper -- powder-sinter technology; Lasers -- Periodicals; 621.36605
• DOI: 10.1088/1555-6611/aa8576
• Languages: English
• ISSNs: 1054-660X

Abstract

Abstract: The use of short local tapers in large mode area fiber amplifiers is proposed for peak power scaling while maintaining good beam quality. To avoid modal distortions, the powder-sintering (REPUSIL) method was employed to obtain core materials with excellent refractive index homogeneity. First experiments with Yb 3+ -doped rod-type amplifiers delivered 2 ns pulses with peak powers of 540 kW and energies of 1.4 mJ for the untapered rod and 230 kW for the tapered rod (limited by facet damage). The beam quality improved from an M 2 value of approximately 10 to 3.5. The investigation of the taper structure indicates room for further improvement.