Sum-frequency generation of 589 nm light with near-unit efficiency

We report on a laser source at 589 nm based on sum-frequency generation of two infrared laser at 1064 nm and 1319 nm. Output power as high as 800 mW are achieved starting from 370 mW at 1319 nm and 770 mW at 1064 nm, corresponding to converting roughly 90% of the 1319 nm photons entering the cavity. The power and frequency stability of this source are ideally suited for cooling and trapping of sodium atoms

Stability of the self-phase-locked pump-enhanced singly resonant parametric oscillator

Steady-state and dynamics of the self-phase-locked (3\omega ==> 2\omega, \omega) subharmonic optical parametric oscillator are analyzed in the pump-and-signal resonant configuration, using an approximate analytical model and a full propagation model. The upper branch solutions are found always stable, regardless of the degree of pump enhancement. The domain of existence of stationary states is found to critically depend on the phase-mismatch of the competing second-harmonic process.Comment: LateX2e/RevteX4, 4 pages, 5 figures. Submitted to Phys. Rev. A (accepted on Jan. 17, 2003

Line intensity measurements of methane’s ν3-band using a cw-OPO

We report on absolute line strength measurements of P(1), R(0) and R(1) singlet lines in the 3:3 μm ν3 (C–H stretching) band of methane 12CH4 at referencetemperature T = 296 K. Line strength measurements are performed at low pressure (P <1 Torr) using direct absorption spectroscopy technique based on a widely tunable continuous-wave singly resonant optical parametric oscillator. The 1σ overall accuracy in line strength determinations ranges between 7 and 8 % mostly limited by pressure and frequency measurements. A comparison with previous reported values is made. Our results show good agreement with the HITRAN 2012 database

Optical, vibrational, thermal, electrical, damage and phase-matching properties of lithium thioindate

Lithium thioindate (LiInS$_{2}$) is a new nonlinear chalcogenide biaxial material transparent from 0.4 to 12 $\mu$m, that has been successfully grown in large sizes and good optical quality. We report on new physical properties that are relevant for laser and nonlinear optics applications. With respect to AgGaS(e)$_2$ ternary chalcopyrite materials, LiInS$_{2}$ displays a nearly-isotropic thermal expansion behavior, a 5-times larger thermal conductivity associated with high optical damage thresholds, and an extremely low intensity-dependent absorption allowing direct high-power downconversion from the near-IR to the deep mid-IR. Continuous-wave difference-frequency generation (5-11$\mu$m) of Ti:sapphire laser sources is reported for the first time.Comment: 27 pages, 21 figures. Replaces the previous preprint (physics/0307082) with the final version as it will be published in J. Opt. Soc. Am. B 21(11) (Nov. 2004 issue

Line intensity measurements of methane’s ν3-band using a cw-OPO

We report on absolute line strength measurements of P(1), R(0) and R(1) singlet lines in the 3:3 μm ν3 (C–H stretching) band of methane 12CH4 at referencetemperature T = 296 K. Line strength measurements are performed at low pressure (P <1 Torr) using direct absorption spectroscopy technique based on a widely tunable continuous-wave singly resonant optical parametric oscillator. The 1σ overall accuracy in line strength determinations ranges between 7 and 8 % mostly limited by pressure and frequency measurements. A comparison with previous reported values is made. Our results show good agreement with the HITRAN 2012 database

LiGaSe2 optical parametric oscillator pumped by a Q-switched Nd:YAG laser

Optical parametric oscillation is demonstrated for the first time with the chalcogenide nonlinear crystal LiGaSe2 pumped by a nanosecond Nd:YAG laser. Angle tuning provides coverage of the 4.8–9.9 μm spectral range in the mid-IR by idler pulses

Réalisation d'un oscillateur paramétrique optique stabilisé en fréquence et accordable continûment sur 500ghz pour la spectroscopie infrarouge

Nous avons développé un oscillateur paramétrique optique simplement résonant (SRO) basé sur un cristal non linéaire de niobate de lithium dopé 5%-MgO et périodiquement polarisé (ppMgCLN). Il est pompé à 1064 nm par une diode laser en cavité étendue balayable continûment de 1050 à 1070 nm injectant un amplificateur Yb-fibré de puissance 10 W. Il génère une onde idler comprise entre 3 et 4 m et une onde signal entre 1450 et 1650 nm. La cavité SRO est asservie sur le pic de transmission d'une cavité Fabry-Perot de grande finesse. Nous avons alors pu démontrer un balayage mono-fréquence sans saut de mode de l'onde idler sur 500 GHz. Cette large accordabilité continue pourrait être utilisée pour la spectroscopie haute résolution multi-espèces dans le moyen infrarouge. Par ailleurs, nous avons revisité la théorie ondes planes du SRO, dont les solutions analytiques ont été données pour la première fois en 1969 par Kreuzer sous la forme d'une équation transcendante, en utilisant une méthode perturbative très puissante qui tient compte de la déplétion de la pompe. Nous avons pu ainsi déterminer les relations d'entrée-sortie du SRO sous la forme de relations explicites très simples, montrant que les puissances de sortie sont proportionnelles à la racine cubique de la puissance pompe.We developed a singly-resonant optical parametric oscillator (SRO) based on a nonlinear crystal of 5%-ppMgCLN congruent lithium niobate chip and pumped at 1064 nm by an extended cavity diode laser widely tuneable from 1050 to 1070 nm injecting a 10 W Yb-fiber amplifier. It generates an idler wave between 3 and 4 m and a signal wave between 1450 and 1650 nm. The SRO cavity is stabilized to the top of a Fabry-Perot transmission fringe. We then demonstrated a mode-hop-free idler tuning range of 500 GHz. This broad continuous tunability could be used for multi-species high resolution spectroscopy in the mid-infrared. Moreover, we have revisited the plane waves SRO theory, whose analytical solutions were given for the first time in 1969 by Kreuzer in the form of a transcendental equation, using a very powerful perturbative method which takes into account the depletion of the pump. We were able to determine the input-output relations of SRO in the form of very simple explicit relationships, showing that the output powers are proportional to the cubic root of the pump power.PARIS-CNAM (751032301) / SudocSudocFranceF

Second-harmonic generation with monolithic walk-off-compensating periodic structures. II. Experiments

International audienceThe theory of periodic walk-off compensation in monolithic structures is tested with type II second-harmonic generation experiments in the YZ plane of KTiOPO4 by use of 2N optically contacted, walk-off-compensating (OCWOC) structures with numbers of plates 2N=10 and 2N=4. The results confirm the theoretical prediction that such structures behave as harmonic birefringence filters whose N-dependent transfer functions select ranges of wavelengths for maximum conversion at normal incidence and extinguish others within the tuning bandwidth curve of nominal birefringence phase matching. The residual plate orientation mismatches that alter the periodicity of the phase-mismatch gratings were found to be responsible both for the reduced second-harmonic enhancement compared with that of a reference bulk crystal of the same total length and for broadening of the tuning bandwidth. The shapes of the tuning curves depend critically on the pump wavelength, displaying a variety of modulated patterns that were previously attributed to plate orientation mismatches. The tuning filter response was found to change with periodicity defects. An enhancement factor of 15 (scalable to 22) compared with a reference bulk crystal was measured with a 10-OCWOC structure of length LC=10 mm

Dynamical Signatures of Self-Phase-Locking in a Triply Resonant Optical Parametric Oscillator

International audienceWe report on specific signatures of self-phase-locking in a cw frequency divide-by-three optical parametric oscillator subject to two competing chi(2) nonlinear processes that couple the signal and idler subharmonic waves. The self-phase-locked pair appears as a broad fringe dip within the mode-pair cluster. We have also observed Hopf instabilities of the zero-detuning case at &tilde;4× the pump threshold. These results open the path to experimental investigation of quantum entanglement and phase-locked transverse mode structures in this novel class of parametric oscillators