OPTICAL ELEMENT AND LIGHT EMISSION SYSTEM

To provide a reliable optical element that is superior in heat conductivity and hardly has warpage of a substrate and peeling of a fluorescent film in high-temperature environment or during irradiation with high-density energy exciting light.SOLUTION: An optical element (1) comprises a substrate (10) and a phosphor layer (20) arranged facing the substrate (10), and the phosphor layer (20) includes a first binder including an inorganic compound and phosphor particles dispersed in the first binder, and also has a first surface (22) facing the substrate (10) and a second surface (23) opposed to the first surface (22). The phosphor layer (20) is parted continuously by a cut part (21) from the first surface (22) to the second surface (23), and at least a part of an inner wall of the cut part (21) in the phosphor layer (20) is formed obliquely to a top surface of the substrate (10).SELECTED DRAWING: Figure 3 【課題】熱伝導性に優れ、且つ高温環境下または高密度エネルギー励起光の照射時に基板の反りや蛍光膜の剥離が生じにくい信頼性の高い光学素子を提供する。【解決手段】光学素子（１）は、基板（１０）と、基板（１０）に面して配置された蛍光体層（２０）とを備え、蛍光体層（２０）は、無機化合物を含む第１のバインダと、前記第１のバインダ内に分散した蛍光体粒子とを含み、蛍光体層（２０）は、基板（１０）に面する第１の面（２２）と、第１の面（２２）と対向する第２の面（２３）とを有し、第１の面（２２）から第２の面（２３）まで連続的に切れ込み部（２１）により蛍光体層（２０）が分断され、蛍光体層（２０）の切れ込み部（２１）の内壁の少なくとも一部は、基板（１０）の表面に対して、傾斜して形成されている。【選択図】図３