Deployment of a spatial light modulator-based beam-shaping system on the OMEGA EP laser

A square flattop beam is a fundamental shape that is in high demand in various applications, such as ultra-high-power lasers, uniform surface processing and medical engineering. In this experiment, a new and simple scheme of the adaptive beam shaping system to generate a square flattop shape with high uniformity and edge steepness using virtual diagonal phase grating encoded on a spatial-light modulator and a 4f system is proposed. The grating vector kg is non-parallel to the normal vectors kx and ky of the objective beam profile to be extracted; thus, the residual and extracted components hit separately on the Fourier plane of the 4f system. Consequently, using a spatial-frequency filter passing components parallel to kx and ky, the residual components are blocked by the filter without loss of the high spatial-frequency domain of the extracted component. When the width of the filter was 1.0 mm, the edge of the shaped beam increased in height within 20 μm, which is less than 20% of that obtained with conventional vertical phase grating.

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“…4d . However, a diamond shape is not typically used in laser systems 6 – 9 . In the third configuration (Fig.…”

Section: Principlementioning

confidence: 99%

“…The wavefront was improved, but it has difficulties in flatness and complexity of the system 23 . Moreover, an adaptive beam shaping technique that uses phase grating encoded on an SLM with spatial-frequency filtering in the Fourier plane in a 4 f system has been developed 6 , 9 , 24 – 28 , as shown in Fig. 1 .…”

Section: Introductionmentioning

confidence: 99%

Utilization of the high spatial-frequency component in adaptive beam shaping by using a virtual diagonal phase grating

Nakata

Osawa

Miyanaga

2019

Sci Rep

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“…However, these are all passive shaping methods used for particular laser system, which is not suitable for achieving high spatial beam quality in complex high-power lasers applied in accurate physics experiments. In recent years, programmable liquid-crystal spatial light modulator (SLM) has been used for adaptive spatial beam shaping and it has been installed onto some large laser systems, such as the National Ignition Facility (NIF) [41] and the OMEGA EP laser [42] . However, there have been only a limited number of reports on spatial beam shaping for high-power lasers using an SLM, especially for medium-scale 100-J lasers [43] .…”

Section: Introductionmentioning

confidence: 99%

Hundred-Joule-level, nanosecond-pulse Nd:glass laser system with high spatiotemporal beam quality

Wang

Lü

et al. 2016

High Pow Laser Sci Eng

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A 100-J-level Nd:glass laser system in nanosecond-scale pulse width has been constructed to perform as a standard source of high-fluence-laser science experiments. The laser system, operating with typical pulse durations of 3-5 ns and beam diameter 60 mm, employs a sequence of successive rod amplifiers to achieve 100-J-level energy at 1053 nm at 3 ns. The frequency conversion can provide energy of 50-J level at 351 nm. In addition to the high stability of the energy output, the most valuable of the laser system is the high spatiotemporal beam quality of the output, which contains the uniform square pulse waveform, the uniform flat-top spatial fluence distribution and the uniform flat-top wavefront.

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“…A dynamic beam-shaping system using a liquid crystal spatial light modulator (SLM) underwent a successful transition from the initial proof-of-principle demonstration [1,2] to an implementation in a high-energy laser such as the OMEGA EP at the University of Rochester [3]. The operation principle of the beam-shaping system is based on the phase-only carrier method, which enables one to have arbitrary two-dimensional (2-D) control of both the laser-beam fluence and wavefront by adjusting the modulation depth and the bias of the carrier phase.…”

Section: Introductionmentioning

confidence: 99%

“…The precompensation of gain inhomogeneity in amplifiers reduces the peak-to-mode in fluence distribution in such a way that the total energy of the beam can be increased without risking damage to the optics. The gain precompensation in OMEGA EP long-pulse (ns) beamlines is achieved in multiple steps using both static and dynamic beam shapers [3,7]. The dynamic beam shaper is located in the low-energy front end, where a residual 2-D correction map is applied to improve the overall system gain precompensation performance and the uniformity of the final output beam.…”

Section: Introductionmentioning

confidence: 99%

Precompensation of gain nonuniformity in a Nd:glass amplifier using a programmable beam-shaping system

Bahk

Begishev

Zuegel

2014

Optics Communications

Self Cite

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A programmable liquid crystal beam-shaping system was installed for a 200-mJ optical parametric chirped-pulse amplification (OPCPA) system front end and was applied to dramatically improve the beam uniformity in the subsequent amplifier. A highly nonuniform beam profile caused by gain inhomogeneity in the amplifier was pre-compensated by the beam shaping system using significantly improved open-loop and closed-loop algorithms. The details of the improved algorithms will be described. The issues of running a liquid crystal device with a high-energy, ultrashort-pulse laser, such as damage risk and temporal contrast degradation, will be addressed.

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Deployment of a spatial light modulator-based beam-shaping system on the OMEGA EP laser

Cited by 21 publications

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Utilization of the high spatial-frequency component in adaptive beam shaping by using a virtual diagonal phase grating

Utilization of the high spatial-frequency component in adaptive beam shaping by using a virtual diagonal phase grating

Hundred-Joule-level, nanosecond-pulse Nd:glass laser system with high spatiotemporal beam quality

Precompensation of gain nonuniformity in a Nd:glass amplifier using a programmable beam-shaping system

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