Patent ID: 9208806
Filing Date: 2015-12-08
Classification: G02B,G11B

Abstract:
1. A near-field light generator comprising: a waveguide including a core through which light propagates, and a cladding provided around the core; and a plasmon generator, wherein the core has a first front end face lying at an end of the core in a first direction, the first direction being a direction of travel of the light propagating through the core, the plasmon generator has a second front end face lying at an end of the plasmon generator in the first direction, the core and the plasmon generator are adjacent in a second direction orthogonal to the first direction, the plasmon generator includes a first portion and a second portion adjacent in the second direction, the second portion including the second front end face, the core includes a main body portion and a protruding portion adjacent in the second direction, the main body portion has a first surface facing toward the plasmon generator, and a second surface opposite to the first surface, the first surface and the second surface being flat surfaces parallel to each other, the first surface includes a first region, a second region and a third region, the first region has an edge located in the first front end face, the second region is contiguous with the first region and is located farther from the first front end face than is the first region, the third region is a region of the first surface other than the first and second regions, the protruding portion lies on the first region, and has a first end face constituting part of the first front end face, and a second end face opposite to the first end face, the cladding includes a receiving-portion-forming layer lying on the third region, the protruding portion and the receiving-portion-forming layer define therebetween a receiving portion, at least part of the first portion of the plasmon generator is received in the receiving portion, the first portion of the plasmon generator includes a first plasmon exciting portion opposed to the second region, and a second plasmon exciting portion opposed to the second end face of the protruding portion, the second region generates first evanescent light based on the light propagating through the core, the second end face of the protruding portion generates second evanescent light based on the light propagating through the core, the plasmon generator is configured so that a first surface plasmon is excited on the first plasmon exciting portion through coupling with the first evanescent light, and a second surface plasmon is excited on the second plasmon exciting portion through coupling with the second evanescent light, and the second front end face of the plasmon generator generates near-field light based on the first and second surface plasmons.