SURFACE PLASMON POLARITON DIRECTION CHANGE DEVICE, INFORMATION RECORDING REPRODUCTION HEAD, PHOTOASSIST MAGNETIC RECORDING DEVICE, AND OPTICAL CIRCUIT

摘要

This invention provides a surface plasmon polariton direction change device (1) for changing the propagation direction of a surface plasmon polariton (5). The surface plasmon polariton direction change device (1) comprises a metal film support member (2),and a first metal film (3) and a second metal film (4), which are provided on a predetermined plane of the metal film support member (2), are adjacent to each other, and are different from each other in effective refractive index. The surface plasmon polariton direction change device (1) is characterized in that the first metal film (3) and the second metal film (4) are provided so that, in at least a part of a boundary line provided between the first metal film (3) and the second metal film (4), the angle of the propagation direction of the surface plasmon polariton (5) to a line perpendicular to the boundary line, i.e., ?, is 0° < ? < 90° or -90° < ? < 0° and one of the metal films on its side remote from the side in contact with the metal film support member (2) flushes with the other metal film, adjacent to the above metal film, on its side remote from the side in contact with the metal film support member (2). The above constitution can provide a surface plasmon polariton direction change device which has a simple construction and can suppress scattering of the surface plasmon polariton at the edge.