Abstract

It has long been known that the problematic quantum phase should and may be treated alongside the rotation angle operator.¹ Also the solution of the quantum phase problem invented by Newton² resembles the orientation angle operator and Ban's concept of phase angle operator³ is similar. The appreciation of Ban's operator as an ideal concept and the interpretation of the Shapiro-Wagner phase operator in the heterodyne detection scheme⁴ as the feasible phase concept have been performed by Hradil.⁵

© 1994 IEEE