  We show theoretically that two evanescently coupled $\chi^{(2)}$ second
harmonic generators inside a Fabry-Perot cavity provide a tunable source of
quadrature squeezed light, Einstein-Podolsky-Rosen correlations and quantum
entanglement. Unlike systems using coupled downconverters, second harmonic
generation has no oscillation threshhold, so that the entangled fields become
macroscopically occupied as soon as the pumping fields are turned on. This
system also gives two frequencies at which the entangled fields can have
macroscopic intensity. We show how the entanglement properties can be
controlled by adjusting the pumping, the coupling strengths and the cavity
detunings.
