Radially Self-Accelerating Optical Pulses

We generalise the concept of radially self-accelerating beams, to the domain of optical pulses. In particular, we show, how radially self-accelerating optical pulses (RSAPs) can be constructed by suitable superpositions of X-waves, which are a natural extension of Bessel beams in the pulsed domain. Moreover, we show, that while field rotating RSAPs preserve their self-acceleration character, intensity rotating RSAPs only possess pseudo self-acceleration, as their transverse intensity distribution is deformed during propagation, due to their propagation-dependent angular velocity

Cylindrically Polarized Nondiffracting Optical Pulses

We extend the concept of radially and azimuthally polarized optical beams to the polychromatic domain by introducing cylindrically polarized nondiffracting optical pulses. In particular, we discuss in detail the case of cylindrically polarized X-waves, both in the paraxial and nonparaxial regime. The explicit expressions for the electric and magnetic fields of cylindrically polarized X-waves is also reported

PT-symmetric photonic quantum systems with gain and loss do not exist

We discuss the impact of gain and loss on the evolution of photonic quantum states and find that PT-symmetric quantum optics in gain/loss systems is not possible. Within the framework of macroscopic quantum electrodynamics we show that gain and loss are associated with non-compact and compact operator transformations, respectively. This implies a fundamentally different way in which quantum correlations between a quantum system and a reservoir are built up and destroyed