Approaching single-photon detection in near-infrared region Appl. Phys. Lett. 101, 141126 (2012) Tm3+ doped silicon thin film and waveguides for mid-infrared sources Appl. Phys. Lett. 101, 141107 (2012) Record-low propagation losses of 154dB/cm for substrate-type W1 photonic crystal waveguides by means of hole shape engineering Appl. Phys. Lett. 101, 131108 (2012) Electro-optic polymer/TiO2 multilayer slot waveguide modulators Appl. We report on the experimental demonstration of adiabatic light transfer between the outer waveguides in a finite array of evanescently coupled optical waveguides with negligible excitation of all the intermediate waveguides. Such a counterintuitive light transfer scheme is an optical analogue of stimulated Raman adiabatic passage via an auxiliary dressed state proposed in atomic physics for multilevel systems. © 2008 American Institute of Physics. Since the pioneering experiments in the early 1970s, 1 arrays of evanescently coupled optical waveguides have at-tracted a continuous interest as integrated optical devices possessing extremely rich optical properties. Already at the linear level, interesting propagation effects, including anomalous refraction and diffraction, 2 Bloch oscillations, 3–6 self-imaging, 7,8 discrete Talbot effect, 9 and quasi-incoherent propagation, 10 have been demonstrated in infinitely extended waveguide arrays. Propagation in spatially finite waveguide arrays has been considered as well. 11–13 Recently, it was sug-gested 13,14 that light transfer in a chain of coupled wave-guides may be conveniently achieved using adiabatic pas-sage schemes that mimic, for optical waves, the well-developed coherent population transfer techniques for atomic or molecular systems. 15,16 For three waveguides, recent experiments 17,18 showed that a suitable control of the cou-pling among the waveguides enables a full light transfer be-tween the two outer waveguides, with negligible excitation of the middle one. Such a rather counterintuitive result, which is the optical analogue of the celebrated stimulated Raman adiabatic passage STIRAP technique 15,16 for three-level atoms, is based on the existence of a dark or trapped state and on adiabatic evolution of the system. Extension of STIRAP to multilevel systems is a nontrivial task owing to the nonexistence of a dark state with no populations in all the intermediate levels. 16 A pulse scheme which dramatically re-duces the intermediate populations was theoretically sug-gested by Malinovsky and Tannor, 19 and later extended and explained in terms of a dressed state approach. 20,21 In such a scheme, which is referred to as straddle STIRAP, the transfer process may be basically reduced to a three-level STIRAP scheme, in which the auxiliary third level is provided by a dressed state of the intermediate levels. 21 Unfortunately, such a scheme has not been demonstrated for atomic systems yet. The optical analogue of straddle STIRAP corresponds to adiabatic tunneling of light waves between the outer waveguides of a finite array, with small excitation of all in-termediate waveguides. It is the aim of this letter to provide the first experimental demonstration of straddle STIRAP for optical waves in a chain of coupled waveguides. A schematic of the waveguide array designed for our experiment is shown in Fig. 1a. The array consists of N straight channel waveguides, of length L = 48 mm and equally spaced by a distance d, which connects two outer circularly curved waveguides L and R in the figure, with opposite curvature of radius R 0 and longitudinally displaced