V. Perinova et A. Luks, Quantum dynamics of damped harmonic oscillator in terms of representationsof the group SU(1,1) and in relation to models of continuous measurement, FORTSCHR PH, 49(10-11), 2001, pp. 1077-1082
Solution of the master equation for the damped harmonic oscillator is expre
ssed in terms of the matrix elements of the representations of the group SU
(1,1). We investigate the role of the group SU(1,1) in the optical attenuat
ion and amplification processes. The connection to the ideal photon and qua
ntum counters is established.