Mr. Espen Lippert Profile

Espen Lippert

Scientist at Norwegian Defense Research Establishment

SPIE Involvement:

Author

Proceedings Article | 19 October 2023 Presentation + Paper

Measuring and modeling the influence of atmospheric turbulence on a 2-µm laser beam

Utku Görkem Yasa, Mehmet Keskin, Ziya Gürkan Figen, Espen Lippert, Helge Fonnum

Proceedings Volume 12731, 1273109 (2023) https://doi.org/10.1117/12.2678501

KEYWORDS: Turbulence, Laser beam propagation, Atmospheric turbulence, Atmospheric propagation, Beam wander, Atmospheric scintillation, Directed infrared countermeasures, Infrared lasers, Numerical simulations

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Within the scope of NATO SET-304 research task group, a field trial was conducted in October/2022 at the ONERA campus located in Le Fauga, Toulouse, France. Part of this trial was devoted to the study of the influence of atmospheric turbulence on laser beam propagation. In this paper, measurement results obtained during the trial for a laser beam degraded by optical turbulence are presented along with the results of analytical expressions and a numerical model. The beam of a 50-Hz pulsed 2-µm laser source (owned and operated by FFI, Norway) was focused on a target screen located approximately 1 km away from the laser emitter. Throughout the trial under various atmospheric turbulence strengths (C_n^2 varying between 5×10-16 m-2/3 and 3×10-13 m-2/3), the scattered laser radiation was captured with an infrared camera (owned and operated by TÜBİTAK BİLGEM/İLTAREN, Türkiye) looking at the nearby target screen in an oblique direction. Also, at different times of the trial, a point receiver setup consisting of two photo-diodes was positioned in the propagation path to directly capture intensity fluctuations of the incident laser beam for further investigation of the turbulence effects. The infrared camera was triggered by a 100-Hz trigger signal that enabled successive recordings of the laser beam profiles and instantaneous background. Several post-processing techniques (background subtraction, 2X soft aperture etc.) are performed on the recordings to correctly evaluate the effect of atmospheric turbulence on laser beams such as beam spreading, wandering, and degradation. Calculated beam metrics such as short- and long-term beam radii and beam wander variance are compared with the results obtained from analytical expressions and it is observed that measurement results match well with theoretical expectations. Furthermore, propagation scenarios encountered in the trial are simulated using a wave-optics-based split-step phase screen model with/without considering temporal dynamics. Numerical model results also show good agreement with the measurement results.

Proceedings Article | 19 October 2023 Presentation + Paper

Optical turbulence on 1-km horizontal path with short and medium IR Gaussian laser beams

Andreas Schiller, Helge Fonnum, Espen Lippert

Proceedings Volume 12731, 127310A (2023) https://doi.org/10.1117/12.2678536

KEYWORDS: Turbulence, Beam wander, Stochastic processes, Optical turbulence, Lasers

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Proceedings Article | 23 April 2020 Presentation + Paper

A Monte Carlo approach to evaluate stray laser energy from the F-35 Lightning II

Gjermund Kjerkreit, Espen Lippert

Proceedings Volume 11410, 1141005 (2020) https://doi.org/10.1117/12.2556362

KEYWORDS: Safety, Nominal ocular hazard distance, Eye, Laser energy, Monte Carlo methods, Electro optical modeling, Data modeling, Target designation, Stochastic processes, Statistical analysis

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Proceedings Article | 7 October 2014 Paper

Laser source with high pulse energy at 3-5 µm and 8-12 µm based on nonlinear conversion in ZnGeP2

Espen Lippert, Helge Fonnum, Magnus Haakestad

Proceedings Volume 9251, 92510D (2014) https://doi.org/10.1117/12.2067046

KEYWORDS: Optical parametric oscillators, Crystals, Laser crystals, Polarization, Optical simulations, Laser sources, Numerical simulations, Laser countermeasures, Resonators, Phase matching

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Proceedings Article | 14 November 2012 Paper

Fiber laser pumped high energy cryogenically cooled Ho:YLF laser

Espen Lippert, Helge Fonnum, Knut Stenersen

Proceedings Volume 8543, 854308 (2012) https://doi.org/10.1117/12.973716

KEYWORDS: Fiber lasers, Resonators, Absorption, Crystals, Laser crystals, Q switched lasers, Holmium, Laser resonators, Cryogenics, Thulium

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Proceedings Article | 5 October 2011 Paper

Progress with OPO-based systems for mid-IR generation

Espen Lippert

Proceedings Volume 8187, 81870F (2011) https://doi.org/10.1117/12.903735

KEYWORDS: Optical parametric oscillators, Crystals, Mid-IR, Resonators, Fiber lasers, Absorption, Directed infrared countermeasures, Quantum cascade lasers, Nonlinear crystals, Mirrors

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Proceedings Article | 20 October 2010 Paper

High power multi-wavelength infrared source

Espen Lippert, Helge Fonnum, Knut Stenersen

Proceedings Volume 7836, 78360D (2010) https://doi.org/10.1117/12.864947

KEYWORDS: Optical parametric oscillators, Resonators, Infrared radiation, Fiber lasers, High power lasers, Holmium, Crystals, Laser resonators, Laser countermeasures, Mid-IR

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Proceedings Article | 2 October 2008 Paper

Tunable high-pulse-energy mid-infrared laser source based on optical parametric amplification in ZnGeP(2)

M. Haakestad, G. Arisholm, E. Lippert, S. Nicolas, G. Rustad, K. Stenersen

Proceedings Volume 7115, 71150Q (2008) https://doi.org/10.1117/12.800079

KEYWORDS: Crystals, Optical parametric oscillators, Mid-IR, Laser crystals, Ferroelectric materials, Optical simulations, Quantum efficiency, Nd:YAG lasers, Nonlinear crystals, Mirrors

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Proceedings Article | 22 April 2008 Paper

High-pulse-energy 8 µm laser source based on optical parametric amplification in ZnGeP2

M. Haakestad, G. Arisholm, E. Lippert, S. Nicolas, G. Rustad, K. Stenersen

Proceedings Volume 6998, 699812 (2008) https://doi.org/10.1117/12.779484

KEYWORDS: Crystals, Optical parametric oscillators, Ferroelectric materials, Nd:YAG lasers, Quantum efficiency, Nonlinear crystals, Laser crystals, Mid-IR, Laser sources, Nonlinear optics

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Proceedings Article | 10 October 2007 Paper

High power and efficient far infrared ZnGeP2-based optical parametric oscillator

Espen Lippert, Gunnar Rustad, Knut Stenersen

Proceedings Volume 6738, 67380D (2007) https://doi.org/10.1117/12.737714

KEYWORDS: Optical parametric oscillators, Crystals, Mirrors, Fiber lasers, Quantum efficiency, Resonators, Reflectivity, High power lasers, Far infrared, Phase matching

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Proceedings Article | 5 October 2006 Paper

High-power fiber-laser-pumped mid-infrared laser sources

Espen Lippert, Stephane Nicolas, Gunnar Arisholm, Knut Stenersen, Asta Villanger, Gunnar Rustad

Proceedings Volume 6397, 639704 (2006) https://doi.org/10.1117/12.689778

KEYWORDS: Optical parametric oscillators, Fiber lasers, Mid-IR, Optical simulations, Crystals, Laser countermeasures, Laser crystals, Resonators, Laser sources, Holmium

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