Non-linear optics encompasses a range of optical phenomena, including two- and three-photon fluorescence, second harmonic generation (SHG), sum frequency generation (SFG), difference frequency generation (DFG), third harmonic generation (THG), coherent anti-Stokes Raman scattering (CARS), and stimulated Raman scattering (SRS). The combined advantages of using these phenomena for imaging complex...

We model spontaneous parametric down-conversion (SPDC) as classical difference frequency generation (DFG) of the pump field and a hypothetical stochastic ``vacuum'' seed field. analytically show that second-order spatiotemporal correlations generated from DFG process replicate those signal SPDC. Specifically, for low gain, is consistent with quantum calculation photon's reduced density matrix; ...

We report optical parametric amplification (OPA) of low-frequency infrared pulses in the intermediate region between terahertz (THz) frequency and mid-infrared (MIR), i.e. , from 16.9 to 44.8 THz (6.7–17.8 ?m). The 255-fs laser output Yb:KGW regenerative amplifier is compressed 11-fs using a multi-plate broadening scheme, which generates THz-to-MIR with spectrum extending approximately 50 by in...

In this work, we propose a novel dual optical frequency comb (DOFC) generation scheme based on cascaded difference (DCDFG). Feasible designs are introduced that enable the two sets of waves, initially generated by DCDFG in an aperiodically periodically poled lithium niobate (APPLN) crystal with pump wave and signal then transferred to high-order Stokes waves oscillations optimization phase mism...

We propose a new approach to quasi-phasematching (QPM) design based on convex optimization. We show that with this approach, globally optimum solutions to several important QPM design problems can be determined. The optimization framework is highly versatile, enabling the user to trade-off different objectives and constraints according to the particular application. The convex problems presente...

The development of a compact tunable mid-IR laser system at 3.5 micrometers for quantitative airborne spectroscopic trace gas absorption measurements is reported. The mid-IR laser system is based on difference frequency generation (DFG) in periodically poled LiNbO3 and utilizes optical fiber amplified near-IR diode and fiber lasers as pump sources operating at 1083 nm and 1562 nm, respectively....

We report on the first characterization of orientation-patterned gallium phosphide (OP-GaP) crystals used to generate narrow-linewidth, coherent mid-infrared (MIR) radiation at 5.85m by difference frequency generation (DFG) of continuous-wave (cw) Nd:YAG laser at 1064nm and diode-laser at 1301nm. By comparison of the experimental absolute MIR efficiency versus focusing to Gaussian beam DFG the...