Abstract: An optical element including a first lens, a second lens, and an optical resin arranged between the lenses. The opposing surfaces of the first lens and the optical resin, and/or the opposing surfaces of the optical resin and the second lens are joined to each other with an adhesive resin having a specific elastic modulus. The first lens is a convex lens and the second lens is a concave lens. The thickness of the center of the optical resin is thicker than the thickness of the outer edge of the optical resin. The second lens has, on its outer periphery, a step structure thinner than the maximum thickness of the second lens. The thickness of the step structure and the thickness of the center of the optical resin satisfy a specific relationship.

Abstract: Provided is a cured product of a resin composition including a (meth)acrylate compound and a compound having at least one thiol group, wherein the content of the compound having at least one thiol group in the cured product is 30 mass % or less, and wherein the cured product has a secondary dispersion characteristic of 0.65 or more.

Abstract: Provided is an optical element that has at least a first optical component, a third optical component. A surface of the second optical component facing the first optical component has a convex shape and a surface of the third optical component facing the second optical component has a concave shape. At least one of the first optical component and the second optical component and the second optical component and the third optical component are bonded by an adhesive layer. The condition 0.2?Ead2/Ead1?0.5 is satisfied, where Ead1 is an elastic modulus of the adhesion layer at 20 degrees Celsius and Ead2 is an elastic modulus of the adhesion layer at 60 degrees Celsius. The condition of 0.25??1/?3<1.0 is also satisfied, where a1 and a3 are coefficients of linear expansion of the first optical component and the third optical component at 20 degrees Celsius to 60 degrees Celsius, respectively.

Abstract: Provided is an optical element that has at least a first optical component, a third optical component. A surface of the second optical component facing the first optical component has a convex shape and a surface of the third optical component facing the second optical component has a concave shape. At least one of the first optical component and the second optical component and the second optical component and the third optical component are bonded by an adhesive layer. The condition 0.2?Ead2/Ead1?0.5 is satisfied, where Ead1 is an elastic modulus of the adhesion layer at 20 degrees Celsius and Ead2 is an elastic modulus of the adhesion layer at 60 degrees Celsius. The condition of 0.25??1/?3<1.0 is also satisfied, where a1 and a3 are coefficients of linear expansion of the first optical component and the third optical component at 20 degrees Celsius to 60 degrees Celsius, respectively.