Four-Beam Tiled-Aperture Coherent Beam Combining of High-Power Femtosecond Laser With Two Compressors

Abstract

The former reports of coherent beam combining (CBC) in the ultra-intense ultra-short laser field focus on the phase control technology and two-beam CBC. To study the four-beam tiled-aperture CBC in the ultra-intense and ultra-short laser field, we demonstrate four-beam CBC of femtosecond laser pulses based on chirped pulse amplification (CPA) scheme. In this experiment, the four beams were compressed using two grating compressors to simulate the situation in ultra-intense and ultra-short laser CBC systems. To achieve real-time measurement of the phase error between the four beams, we introduced a continuous reference laser and the phases of beams 2, 3, and 4 were locked to beam 1.A combined efficiency of 57% was achieved. Although the coherent combining efficiency is not very high, the possibility of a fourbeam CBC based on the CPA scheme was confirmed, especially with different grating compressors which can reduce the limitation of gratings in single beam petawatt lasers. Finally, the remaining difficulties in the implementation of CBC of four beams and the methods to improve its efficiency were analyzed. The use of CBC in ultra-intense and ultrashort laser systems is of considerable significance.

Coherent combining of broadband pulses after free space optical parametric amplification

“…Nevertheless, the requirement of focusing high peak power pulsed-beams into tiny glass tubes makes the energy scaling capabilities and longevity of such systems rather questionable. The aforementioned issues can be avoided in free space beam propagation, yet only a few experimental efforts exist where the aim was to combine broadband sub-50 fs transform-limited duration (TLD) high energy (≈ mJ level) wave-packets [7][8][9][10][11][12][13]. This type of research is focused exclusively on tiled-aperture [2] CBC in the far-field, in efforts to achieve ultra-relativistic peak intensity around 10 24 − 10 25 W cm 2 [11,14].…”

Coherent combining of broadband pulses after free space optical parametric amplification

“…Nevertheless, the requirement of focusing high peak power pulsed-beams into tiny glass tubes makes the energy scaling capabilities and longevity of such systems rather questionable. The aforementioned issues can be avoided in free space beam propagation, yet only a few experimental efforts exist where the aim was to combine broadband sub-50 fs transform-limited duration (TLD) high energy (≈ mJ level) wave-packets [7][8][9][10][11][12][13]. This type of research is focused exclusively on tiled-aperture [2] CBC in the far-field, in efforts to achieve ultra-relativistic peak intensity around 10 24 − 10 25 W cm 2 [11,14].…”

Deep learning assisted far-field multi-beam pointing measurement

“…Coherent beam combination (CBC) is a promising technique to solve the output problem from another direction 8 – 10 Experts attempt to combine multi-channel lasers to achieve higher output power. Several institutions have projected to utilize the CBC scheme to improve the output capacity of their ultra-fast laser facilities to the 100 PW class 5 , 7 …”