ABSTRACT
Waveguides: Basic Equations...............................................................................................312 13.3 Coherent Destruction of Optical Tunneling ..........................................................................314 13.4 Optical Analog of Field-Induced Barrier Transparency........................................................316 13.5 Coherent Photonic Tunneling by Adiabatic Passage.............................................................319 13.6 Photonic Tunneling in Optical Lattices: Optical
Analog of the Quantum Zeno Effect ....................................................................................325 13.7 Photonic Landau-Zener Tunneling .......................................................................................331 13.8 Conclusions ...........................................................................................................................333 References......................................................................................................................................334
Tunneling is a universal phenomenon to wave physics which arises when an evanescent field transfers energy through a barrier to a region where a propagating wave is allowed. Tunneling phenomena have been predicted and observed in countless quantum and classical physical systems. In particular, optical (or photonic) tunneling usually refers to light propagation across forbidden photonic barriers, such as in photonic band gap structures or undersized waveguides, as well as to evanescent field coupling among waveguides or resonators or to light passage via evanescent coupling in frustrated total internal reflection (FTIR). The first observation of FTIR and of photonic tunneling date back to three centuries ago, when Newton reported on light transmission through a gap between prisms. Nowadays, FTIR at plane interfaces is generally viewed as an optical analog of quantum mechanical tunneling across a one-dimensional potential barrier [1]. Optical tunneling across photonic barriers, realized by for example, FTIR or photonic band gaps, has attracted a great deal of attention in the past two decades as an experimentally accessible system with which to measure tunneling times [2-7]. FTIR has been also exploited to study wave packet reshaping [8] and to provide an optical realization of curious quantum-mechanical effects such as quantum evaporation [9]. Similarly, photonic tunneling in spherical dielectric media has been proposed as an optical analog of nuclear decay arising form particle escape from a three-dimensional potential well [10]. In deformed dielectric microcavities, chaos-assisted tunneling phenomena have been investigated as well [11-14]. A different optical system that provides an experimentally accessible laboratory tool to visualize and control photonic tunneling, which is at the focus of this chapter, is represented
