Idler Input Research Articles

Modeling high-peak-power few-cycle field waveform generation by optical parametric amplification in the long-wavelength infrared.

Extended coupled-wave analysis of optical parametric chirped-pulse amplification (OPCPA) reveals regimes whereby high-peak-power few-cycle pulses can be generated in the long-wavelength infrared (LWIR) spectral range. Broadband OPCPA in suitable nonlinear crystals pumped at around 2 μm and seeded either through the signal or the idler input is shown to enable the generation of high-power field waveforms with pulse widths shorter than two field cycles within the entire LWIR range.

Modeling and measurement of the noise figure of a cascaded non-degenerate phase-sensitive parametric amplifier

Semi-classical noise characteristics are derived for the cascade of a non-degenerate phase-insensitive (PI) and a phase-sensitive (PS) fiber optical parametric amplifier (FOPA). The analysis is proved to be consistent with the quantum theory under the large-photon number assumption. Based on this, we show that the noise figure (NF) of the PS-FOPA at the second stage can be obtained via relative-intensity-noise (RIN) subtraction method after averaging the signal and idler NFs. Negative signal and idler NFs are measured, and <2 dB NF at >16 dB PS gain is estimated when considering the combined signal and idler input, which is believed to be the lowest measured NF of a non-degenerate PS amplifier to this date. The limitation of the RIN subtraction method attributed to pump transferred noise and Raman phonon induced noise is also discussed.

Enhancement in quantum noise correlation between the two outputs of a nondegenerate optical amplifier with a non-vacuum state idler input

The theoretical limit of the noise correlation between the signal and idler outputs of a nondegenerate optical parametric amplifier (NOPA) with a coherent state signal and vacuum state idler input can be enhanced if a non-vacuum coherent state idler input is employed. By choosing a balanced signal and idler input, the noise correlation is $1/{({\root}g + {\root}{g-1})}^2$ , where g is the intensity gain of the NOPA, and that is superior to the prediced outputs with single signal input by approximately 3dB. The result is applicable to all the schemes that use the NOPA to produce a sub-shot noise light generation such as feed-back or feed-forward control.

Phase relationships and power gains of a SUPARAMP with a correlated double-sideband input

The input-output phase relationships for the doubly degenerate superconducting unbiased parametric amplifier (SUPARAMP) are given. The general analysis is performed for the case when the information is injected into both the signal and idler input channels of the amplifier and the phases of the signal, idler, and pump waves are correlated. The expressions for the phase-dependent power gains are evaluated. The operation for a double-sideband input with symmetry and the usual single-sideband input is treated as a special case. Double-sideband input operation may result in an effective increase of the output signal-to-noise ratio. Another improvement in the signal processing can be achieved by synchronous detection of the SUPARAMP's output.