This paper presents a high-intensity source of polarization-entangled photon pairs with high momentum definition. The source uses type-II noncollinear phase matching in parametric down conversion to produce true entanglement, where no part of the wave function must be discarded. The source allows for the ready preparation of all four EPR-Bell states. The experiment demonstrated a violation of Bell's inequality by over 100 standard deviations in less than 5 minutes, with two-photon fringe visibilities exceeding 97%. The source is more than an order of magnitude brighter than previous sources for polarization-entangled photons, with coincidence rates greater than 1500 s⁻¹. The high net detection efficiency (>10%) is an important step towards a loophole-free Bell-inequality experiment. The source has several advantages, including being relatively insensitive to larger collection irises, and being simpler and more stable than other down-conversion setups. The technique is expected to find immediate application in many experiments requiring a stable source of easily controllable entangled states of two particles, including quantum communication, quantum cryptography, teleportation, entanglement swapping, and quantum computation. The source is also important for investigations of the foundations of quantum mechanics. The experiment was supported by the Austrian Science Foundation and the U.S. National Science Foundation.This paper presents a high-intensity source of polarization-entangled photon pairs with high momentum definition. The source uses type-II noncollinear phase matching in parametric down conversion to produce true entanglement, where no part of the wave function must be discarded. The source allows for the ready preparation of all four EPR-Bell states. The experiment demonstrated a violation of Bell's inequality by over 100 standard deviations in less than 5 minutes, with two-photon fringe visibilities exceeding 97%. The source is more than an order of magnitude brighter than previous sources for polarization-entangled photons, with coincidence rates greater than 1500 s⁻¹. The high net detection efficiency (>10%) is an important step towards a loophole-free Bell-inequality experiment. The source has several advantages, including being relatively insensitive to larger collection irises, and being simpler and more stable than other down-conversion setups. The technique is expected to find immediate application in many experiments requiring a stable source of easily controllable entangled states of two particles, including quantum communication, quantum cryptography, teleportation, entanglement swapping, and quantum computation. The source is also important for investigations of the foundations of quantum mechanics. The experiment was supported by the Austrian Science Foundation and the U.S. National Science Foundation.