Progress Toward Spatially-Entangled Photon-Pair Generation in a Few-Mode Fiber

We describe a scheme for generation of spatial-mode-entangled photon pairs in a few-mode fiber and experimentally demonstrate generation of idler beams from classical seed signals representing various superpositions of fiber LP
₀₁
and LP
_11a
modes. For every signal mode superposition, we observe the indication of idler mode orthogonality to the signal mode.