ABSTRACT
CONTENTS Acknowledgments............................................................................................... 160 Appendix:.Overlap.Integral.〈γ1|γ2 〉.for.Photons............................................... 161 References............................................................................................................. 162
We.review.and.sharpen.the.concept.of.a.photon.wave.function.based.on.the. quantum.theory.of.light..We.argue.that.a.point-like.atom.serves.as.the.archetype.for.both.the.creation.and.detection.of.photons..Spontaneous.emission. from.atoms.provides.a.spatially.localized.source.of.photon.states.that.serves. as.a.natural.wave.packet.basis.for.quantum.states.of. light..Photodetection. theory.allows.us.to.give.operational.meaning.to.the.photon.wave.function. which,.for.single.photons,.is.analogous.to.the.electric.field.in.classical.wave. optics..Entanglement.between.photons,.and.the.uniquely.quantum.phenomena.that.result.from.it,.are.exemplified.by.two-photon.wave.functions.
