Theoretical and numerical investigations of parametric transfer via difference-frequency generation for indirect mid-infrared pulse shaping

Abstract

We theoretically and numerically investigate indirect mid-infrared pulse shaping via parametric transfer, specifically difference-frequency generation. We define a quantitative measure for the fidelity of parametric transfer, and investigate the effect of material dispersion and process nonlinearity on the parametric transfer. We show that a good fidelity transfer of a broadbandwidth pulse can be efficiently achieved with a reasonable wavelength tunability, by careful design of the experimental configuration.

High-energy, near- and mid-IR picosecond pulses generated by a fiber-MOPA-pumped optical parametric generator and amplifier

“…The idler spectral FWHM bandwidth was measured to be 6 nm. As expected, the frequency bandwidth was essentially transferred from pump (4.7 cm -1 ) to idler (5.4 cm -1 ) [17]. No Raman peaks were observed in this case as the narrower linewidth did not seed its generation.…”

Experimental investigation of parametric transfer in synchronously pumped optical parametric oscillators

“…A more detailed explanation of this mechanism is given Ref. [19]. We find that our experimental SPOPO results agree with these numerical predictions.…”

“…1 with mirrors of different signal reflectivities. Our numerical investigations found that increasing the resonator loss and hence increasing the required signal gain worsens the transfer fidelity as is predicted by the single pass DFG process [19]. Moreover, we have observed both theoretically [20] and experimentally that a high resonator loss reduces the effect of the etalon as the signal bandwidth is broader at steady state.…”

“…Following this demonstration of the potential for this adaptive MIR pulse shaping technique, we progressed to numerical studies of the fidelity of transfer, firstly in the simple single pass DFG process [19] and then to the somewhat more complicated case of the SPOPO [20]. The effects of temporal walk-off (TWO), group delay dispersion (GDD), signal bandwidth, signal amplification and pump depletion were considered.…”

Near-degenerate doubly resonant synchronously pumped OPO for intracavity THz generation

“…GaAs has many attractive properties for THz generation such as a small THz absorption coefficient, small mismatch between the optical group index (n g,opt ≈ 3.41) 8 and THz phase index (n THz ≈ 3.6), 9 large thermal conductivity, large nonlinear coefficient, and well-established QPM fabrication techniques. 10 Using a split-step Fourier method and known cavity modeling techniques, 11,12 we have constructed a temporal model of the steady-state behavior of the SP OPO including material dispersion, resonator-length detunings, and intracavity losses. We experimentally and theoretically investigated the relative positions of the signal and idler pulses as well as the pulse shapes as a function of separate signal and idler cavity lengths.…”