Applied Physics B

, Volume 99, Issue 4, pp 657-671

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

Noise reduction in 3D noncollinear parametric amplifier

  • P. MigdałAffiliated withInstitute of Experimental Physics, University of Warsaw Email author 
  • , W. WasilewskiAffiliated withInstitute of Experimental Physics, University of Warsaw


We analytically find an approximate Bloch–Messiah reduction of a noncollinear parametric amplifier pumped with a focused monochromatic beam. We consider type I phase matching. The results are obtained using a perturbative expansion and scaled to the high-gain regime. They allow for a straightforward maximization of the signal gain and minimization of the parametric fluorescence noise. We find the fundamental mode of the amplifier, which is an elliptic Gaussian defining the optimal seed beam shape. We conclude that the output of the amplifier should be stripped of higher-order modes, which are approximately Hermite–Gaussian beams. Alternatively, the pump waist can be adjusted such that the amount of noise produced in the higher-order modes is minimized.