EVANESCENT LIGHT GENERATOR

PROBLEM TO BE SOLVED: To provide a low-cost evanescent light generator which can generate an evanescent Bessel light with a large focal depth and a variable region.SOLUTION: The evanescent light generator includes a lens 4 in the shape of a conical board having a board surface 4a, a conical surface 4b, and a vertex 4p. A ring beam is reflected by the conical surface 4b to the vertex 4p of the conical surface 4b, and is entirely reflected by the board surface 4a located between the vertex 4p and the part where the reflected light is reflected again, and interferes with the surface so that a Bessel light is generated.SELECTED DRAWING: Figure 1 【課題】焦点深度が深く領域が可変のエバネッセントベッセル光を発生できる低コストのエバネッセント光発生装置を提供する。【解決手段】本発明のエバネッセント光発生装置は、環状のビームが円錐面４ｂで該円錐面４ｂの頂点４ｐ側に反射し、該反射した反射光が該反射した箇所と前記頂点４ｐとの間に配置される台面４ａで全反射し干渉してベッセルビームが生成される円錐台様レンズ４を備えている。【選択図】図１