Browsing by Author "Rustad, Gunnar"
Now showing items 1-20 of 20
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Beam shaping of high power laser diode bars
Rustad, Gunnar; Lippert, Espen; Stenersen, Knut (2001)A technique for reshaping the highly astigmatic beam from a high-power laser diode bar by use of two parallel mirrors is studied theoretically and experimentally. It is found that the output from the 1 µm x 1 cm laser ... -
Comparison of 294 nm and 355 nm excitation wavelengths in UVLIF standoff detection of biological aerosols released in a semi-closed chamber
Farsund, Øystein; Rustad, Gunnar; Skogan, Gunnar (2012-02-07)FFI has previously developed a lidar for standoff detection of biological aerosols based on ultraviolet laser induced fluorescence, using an excitation wavelength at 355 nm. A 294 nm laser source has been developed and ... -
Design of a high pulse energy coherent ultraviolet source - simulations and experimental design
Rustad, Gunnar; Farsund, Øystein (2013-02-01)The report discusses design considerations and numerical simulations of different system architectures for generation of several tens of mJ pulse energy in the ultraviolet range around 290- 300 nm. The architectures ... -
Eye-safe fiber laser for long range 3D imaging applications
Holmen, Lars Grønmark; Rustad, Gunnar; Haakestad, Magnus W. (2018)We report an all-fiber Er/Yb master oscillator power amplifier at 1.55 μm, delivering 135 μJ pulses with 6 ns duration (full width at half-maximum) at 100 kHz pulse repetition frequency, limited by stimulated Brillouin ... -
High pulse energy and symmetrical far field from an optical parametric oscillator in the red spectral range
Rustad, Gunnar; Farsund, Øystein (2011)Red pulses with >30 mJ energy and <0.6 nm bandwidth have been demonstrated using a type 2 phase matched optical parametric oscillator pumped at 532 nm. A symmetrical signal beam with beam diameter-divergence product of ~3 ... -
High-pulse-energy, linear optical parametric oscillator with narrow and symmetrical far field
Farsund, Øystein; Rustad, Gunnar (2013)A new method to obtain a narrow and symmetrical far field from a high-pulse-energy optical parametric oscillator (OPO) with a linear resonator has been tested. The OPO employs two identical nonlinear crystals that are cut ... -
Mid-infrared optical parametric oscillators based on periodically-poled lithium niobate
Arisholm, Gunnar; Stenersen, Knut; Rustad, Gunnar; Lippert, Espen; Haakestad, Magnus (2002)A study has been conducted of mid-infrared optical parametric oscillators (OPOs) based on periodically poled lithium niobate (PPLN) as the nonlinear optical material. Experiments have been performed with a number of 1.06 ... -
Optical parametric master oscillator and power amplifier for efficient conversion of high-energy pulses with high beam quality
Arisholm, Gunnar; Nordseth, Ørnulf; Rustad, Gunnar (2004)We describe a system for parametric conversion of high-energy, Q-switched laser pulses from 1.064 µm to 2.1 µm in KTiOPO4. High beam quality and efficiency are obtained by use of a two-stage system: An optical parametric ... -
Optical parametric oscillators with high pulse energy and beam quality
Rustad, Gunnar; Farsund, Øystein; Arisholm, Gunnar (2010)A new method for obtaining high beam quality from high pulse energy optical parametric oscillators (OPOs) is demonstrated. By using different nonlinear crystals that have walk-off in orthogonal directions but are type 2 ... -
Optimal classification of standoff bioaerosol measurements using evolutionary algorithms
Nyhavn, Ragnhild; Moen, Hans Jonas Fossum; Farsund, Øystein; Rustad, Gunnar (2011)Early warning systems based on standoff detection of biological aerosols require real-time signal processing of a large quantity of high-dimensional data, challenging the systems efficiency in terms of both computational ... -
A review of theory and materials for optical parametric oscillators in the infrared
Arisholm, Gunnar; Rustad, Gunnar (1997) -
Robust eye-safe pulsed fiber laser source for 3D ladar applications
Holmen, Lars Grønmark; Rustad, Gunnar; Haakestad, Magnus W. (2017)We present a pulsed all-fiber Er/Yb-doped master oscillator power amplifier at 1.55 μm wavelength. In a simple two-stage amplifier design, the source delivers 140 μJ pulses at 25 kHz and 50 kHz pulse repetition frequency, ... -
Standoff detection of biological aerosols by means of UV-laser induced fluorescence : results from Umeå trial 2006
Farsund, Øystein; Rustad, Gunnar (2008)The objective of standoff detection is to enable early warning in case of a biological warfare agent attack. FFI has built a demonstrator employing ultraviolet laser induced fluorescence of biological aerosols. The field ... -
Standoff detection of biological aerosols by UV-laser induced fluorescence
Rustad, Gunnar; Farsund, Øystein (2008)Denne rapporten beskriver et eksperimentelt instrument som kalles biolidar og som er utviklet ved FFI i perioden 2005-2007. Biolidaren har som formål å oppdage aerosoler med biologisk innhold for å kunne gi tidlig oppdagelse ... -
Standoff detection of biological agents using laser induced fluorescence - a comparison of 294 nm and 355 nm excitation wavelengths
Farsund, Øystein; Rustad, Gunnar; Skogan, Gunnar (2012)Standoff detection measuring the fluorescence spectra of seven different biological agents excited by 294 nm as well as 355 nm wavelength laser pulses has been undertaken. The biological warfare agent simulants were released ... -
Sum-frequency generation of high-energy and hig-beam-quality ultraviolet pulses
Farsund, Øystein; Rustad, Gunnar (2011)Sum-frequency generation of UV pulses exceeding 25 mJ and with beam quality has been demonstrated by mixing the third harmonic pulses of a flash lamp pumped 1.06 μm Nd:YAG laser with 1.7 μm pulses from an optical parametric ... -
Technologies for standoff detection of liquid warfare agents
Rustad, Gunnar (2011-10-20)The topic of this report is a review of technologies that can be used for standoff detection of chemical warfare agents in the liquid phase, with the aim to point out technologies that could be topic of a further study. ... -
Thermal effects in end-pumped solid state lasers - influence on resonator stability, beam quality, and output power
Stenersen, Knut; Lippert, Espen; Rustad, Gunnar; Arisholm, Gunnar (2001)A theoretical analysis is given of the magnitudes of thermal effects in end-pumped high-power solid state lasers, and their influence on the laser output characteristics, particularly the beam quality and conversion ... -
Vurdering av teknologier for avstandsdeteksjon av radiologisk materiale
Rustad, Gunnar (2009)Rapporten gir en oversikt over teknologier som kan brukes i jakten på radioaktivt materiale eller kjernevåpen som er utenfor deteksjonsavstanden til tradisjonelle detektorer som for eksempel geiger-tellere. Mulige ... -
ZnGep2-based optical parametric oscillator for µm generation
Arisholm, Gunnar; Lippert, Espen; Stenersen, Knut; Rustad, Gunnar; Nicolas, Stephane (2004)Operation of a ZnGeP2-based optical parametric oscillator (OPO) for generation of 8-11 μm radiation is studied. The primary source used to pump the OPO is a KTP-based OPO pumped by a Nd:YAG laser, giving up to 2 mJ pump ...