Quantum optics: quantum, classical, and metaphysical aspects

Intensity interference 1114 6.1 Tw o type s of intensit y interference ; 6.2 Brow n - Twis s intensit y interference ; 6.3 Advance d wave s interference ; 6.4 Simultaneou s observatio n of tw o type s of interference ; 6.5 Classica l model s 7. Conclusion 1120 References 1122 Abstract. Presented belo w is th e critical review of th e moder n optical experiment s devote d to th e demonstratio n of th e quantu m natur e of light an d which reveal th e propertie s of photons . Th e thre e mai n language s used for th e description of such demonstratio n experiment s are described an d compared : th e forma l quantu m languag e Q, which enables calculation of all averaged experimenta l data ; th e classical or semiclassical languag e C, which allows a visual qualitative description of som e effects; th e metaphysica l languag e M, which uses vaguely defined term s (such as photons , their duality, quantu m nonlocality, etc.) an d provide s no ne w observabl e results, bu t claims to offer th e mos t profoun d reflection of th e quantum-optica l phenomena . It is propose d to distinguish th e thre e types of photons : Q-photo n (the Foc k state with n = 1), C-photo n (the classical wav e packet) , an d M-photo n (the hypothetica l elementar y particle producin g discrete pulses at th e photo n detector output , an d which ha s no t yet been defined in th e framewor k of an y consistent theory) .