Fundamental eigenmode of traveling-wave phase-sensitive optical parametric amplifier: experimental generation and verification

Abstract

We investigate experimentally the eigenmodes of a Gaussian-beam-pumped traveling-wave phase-sensitive optical parametric amplifier (PSA). By varying the waist of an input LG(00) signal mode, we show that PSA performance improves with increasing spatial overlap between the input and the theoretically predicted fundamental eigenmode. For optimum waist, we report amplification and deamplification markedly higher than those observed for the traditional case of signal waist=√2× (pump waist). Lastly, we demonstrate the generation and verification of the PSA fundamental eigenmode.

Devices for quantum communication over mode-division-multiplexing systems

“…First, based on our previous studies of the nonlinear mode interactions in spatially-multimode optical parametric amplifiers in free space [6][7][8][9] and multimode waveguides [10], we have developed a scheme for a spatial-mode demultiplexer based on sum-frequency generation (SFG) in a two-mode PPLN waveguide [11,12]. We have experimentally demonstrated such a demultiplexer, in which, by adjusting the spatial profile of a 1560-nm pump wave, we could selectively upconvert either mode TM00, or mode TM01, or any superposition of these two modes of a 1540-nm signal to TM01 mode at 775 nm, for both classical [13,14] and single-photon-level [14,15] signals.…”