Search results for "Wave mixing"
showing 10 items of 107 documents
Enhanced photorefractive properties of Bi-doped Sn2P2S6
2008
International audience; Enhanced photorefractive properties of tin hypothiodiphosphate (Sn2P2S6) crystals as a result of Bi doping are presented. These new crystals were obtained by the vapor-transport technique using stoichiometric Sn2P2S6 composition with an additional amount of Bi up to 0.5 mol. % in the initial compound. The bandgap edges of the obtained crystals are located at ~750 nm and shift toward the red wavelengths with increasing Bi concentration. Sn2P2S6:Bi crystals are found to exhibit larger two-beam coupling gain coefficients (up to 17 cm−1 at a wavelength of 854 nm) as compared to (i) pure Sn2P2S6 (2.5 cm−1 at 854 nm), (ii) Sn2P2S6 crystals modified by the growth conditions…
Real-time monitoring of graphene patterning with wide-field four-wave mixing microscopy
2016
The single atom thick two-dimensional graphene is a promising material for various applications due to its extraordinary electronic, optical, optoelectronic, and mechanical properties. The demand for developing graphene based applications has entailed a requirement for development of methods for fast imaging techniques for graphene. Here, we demonstrate imaging of graphene with femtosecond wide-field four-wave mixing microscopy. The method provides a sensitive, non-destructive approach for rapid large area characterization of graphene. We show that the method is suitable for online following of a laser patterning process of microscale structures on single-layer graphene. peerReviewed
Frequency tunable polarization and intermodal modulation instability in high birefringence holey fiber
2009
International audience; We present an experimental analysis of polarization and intermodal noise-seeded parametric amplification, in which dispersion is phase matched by group velocity mismatch between either polarization or spatial modes in birefringent holey fiber with elliptical core composed of a triple defect. By injecting quasi-CW intense linearly polarized pump pulses either parallel or at 45 degrees with respect to the fiber polarization axes, we observed the simultaneous generation of polarization or intermodal modulation instability sidebands. Furthermore, by shifting the pump wavelength from 532 to 625 nm, we observed a shift of polarization sidebands from 3 to 8 THz, whereas int…
Tuning four-wave mixing through temperature in ethanol-filled photonic crystal fiber
2016
In this paper, continuous tuning of four-wave mixing bands in an ethanol-filled photonic crystal fiber is investigated. A wide tuning range of the parametric bands, from 745 nm to 920 nm (signal) and from 1260 nm to 1710 nm (idler), is achieved through the thermo-optic effect. This corresponds to a frequency tuning range higher than 2000 cm−1; such wide range can be particularly useful in applications that require broadband wavelength conversion, e.g., CARS microscopy. Numerical calculations are in good agreement with experimental measurements.
Broadband Tuning of Four-Wave Mixing Bands Using Photonic Crystal Fibers
2016
We present an experimental study of the shift with temperature of widely-spaced FWM parametric bands generated in an ethanol-inflltrated photonic crystal fiber. We report broadband tuning of 175 nm and over 500 nm for the signal and idler bands, respectively, achieved through the thermo-optic effect. Numerical calculations were carried out and show good agreement with experimental data.
Wideband tuning of four-wave mixing in solid-core liquid-filled photonic crystal fibers
2016
We present an experimental study of parametric four-wave mixing generation in photonic crystal fibers that have been infiltrated with ethanol. A silica photonic crystal fiber was designed to have the proper dispersion properties after ethanol infiltration for the generation of widely spaced four-wave mixing (FWM) bands under 1064 nm pumping. We demonstrate that the FWM bands can be tuned in a wide wavelength range through the thermo-optic effect. Band shifts of 175 and over 500 nm for the signal and idler bands, respectively, are reported. The reported results can be of interest in many applications, such as CARS microscopy.
Four Wave Mixing in Photonic Crystal Fibers:<br /> Tuning Techniques
2016
We present an experimental and numerical study of four-wave mixing in photonic crystal fibers. Our objective is the development of tuning techniques based on tailoring de dispersion of the fibers. We demonstrate wide tuning ranges.
Polarization backward-wave four-wave mixing in BaTiO_3:Fe using the photovoltaic effect
1997
We report the first study to our knowledge of polarization backward-wave four-wave mixing in a BaTiO3:Fe crystal and compare the results of our measurements with the calculations performed within the model of photovoltaic charge transport. Two identically polarized pump waves and one orthogonally polarized signal wave are sent to a sample in a plane normal to the crystal’s C axis; a phase-conjugate wave with polarization identical to that of the signal wave is generated. With a 2-mm-thick sample a phase-conjugate reflectivity Rpc≈0.01 is reached; for a 1-cm-thick sample, amplified reflection should be possible.
Alignment-free, all-spliced fiber laser source for CARS microscopy based on four-wave-mixing
2012
An environmentally-stable low-repetition rate fiber oscillator is developed to produce narrow-bandwidth pulses with several tens of picoseconds duration. Based on this oscillator an alignment-free all-fiber laser for multi-photon microscopy is realized using in-fiber frequency conversion based on four-wave-mixing. Both pump and Stokes pulses for coherent anti-Stokes Raman scattering (CARS) microscopy are readily available from one fiber end, intrinsically overlapped in space and time, which drastically simplifies the experimental handling for the user. The complete laser setup is mounted on a home-built laser scanning microscope with small footprint. High-quality multimodal microscope image…
Polarization Modulation Instability in All-Normal Dispersion Microstructured Optical Fibers With Quasi-Continuous Pump
2019
We report the experimental observation of the polarization modulation instability (PMI) effect in all-normal dispersion (ANDi) microstructured optical fibers (MOFs) with quasi-continuous pumping. The small unintentional birefringence (~10-5), that any realistic non-polarization maintaining MOF exhibits, contributes to this nonlinear effect. PMI can produce two sidebands whose polarization state is orthogonal to the polarization of the pump. In this work, only one type of PMI process is observed, i.e., when the pump is polarized along the slow axis of the fiber and sidebands are generated in the fast axis mode. This PMI process was studied experimentally in two ANDi fibers with different dis…