Versatile, compact chirped pulse amplifier pump system for ultrafast optical parametric amplifiers

Abstract

We report on the development of a pump system for ultrafast optical parametric amplifiers (uOPA) as an upgrade for the existing uOPA at the Petawatt High Energy Laser for heavy Ion eXperiments (PHELIX) and the new Petawatt ENergy-Efficient Laser for Optical Plasma Experiments (PEnELOPE). The system consists of a two-stage chirped pulse amplifier, centered around a high energy Yb:YAG regenerative amplifier that delivers 108 mJ uncompressed output energy, resulting in 92 mJ at 1030 nm after compression, pulse durations of 1.4 ps, a high beam quality of M x / y 2 = 1.02 / 1.16 and a relative energy stability of 0.35 %. A second harmonic generation (SHG) efficiency of up to 70 % is achievable and a maximum pulse energy of 43 mJ at 515 nm has been obtained, which is only limited by the damage threshold of the SHG crystal. A self-phase modulation stage makes this system a widely applicable, self-seedable pump module for uOPA without placing strong requirements on its seed oscillator.

Millijoule ultrafast optical parametric amplification as replacement for high-gain regenerative amplifiers

“…The following section will briefly cover the experimental setup of the uOPA, starting with the layout of the pump system, its working parameters and key features. A detailed description of the architecture of this pump laser can be found in a recent publication of our group [ 27 ] . Subsequently, we describe the details of the uOPA architecture before presenting the performance of the system as a stand-alone system and as a fully implemented high-contrast module.…”

“…As shown in the previous section, the amplifier provides a sufficiently high beam quality and a sufficient amount of energy, yet its energy stability has still to be shown. Of course, the stability of the pump has the largest influence, but with an energy stability of 0.35% [ 27 ] it provides a stable basis. Independent of the pump energy, the slow time drift between the pump and signal has to be considered.…”

Synchronized off-harmonic probe laser with highly variable pulse duration for laser–plasma interaction experiments

“…A more detailed description of this amplifier can be found in Ref. [18]. A leakage with a pulse energy of approximately 10 µJ is sent towards the pulse-conditioning stage, shown in Figure 2.…”

“…The black boxes correspond to the PHELIX beamline, starting from a short-pulse oscillator. A fraction of this pulse feeds an amplifier, providing the energy for the pump pulse of the subsequent ultra-fast optical parametric amplifier (uOPA) stage [ 18 ] . Within the following chirped pulse amplification (CPA) chain of the PHELIX facility, the pulse is temporally stretched, amplified and re-compressed before propagating towards the target chamber [ 17 ] .

Figure 1 Scheme of the principle of the SEPPL (blue boxes) integrated into the PHELIX facility (black boxes).

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“…The regenerative amplifier used to amplify the seed pulse shares a common design with the uOPA pump [ 18 ] . It runs at a repetition rate of 10 Hz, synchronized with the front end and independent of the full-energy shots of the PHELIX facility.…”