Abstract: A diffractive optical element prevents degradation of the optical performance of the element due to moisture absorption of the resin layers from taking place and also can prevent cracks of the resin layers and peeling of the resin layers along the interface thereof from taking place in a hot environment or in a cold environment. The diffractive optical element comprises a first layer and a second layer sequentially laid on a substrate, a diffraction grating being formed at the interface of the first layer and the second layer, the height d of the diffraction grating, the average film thickness t1 of the first layer and the average film thickness t2 of the second layer satisfying the relationship requirements expressed by the expressions of 1.1×d?t1?50 ?m and 30 ?m?t2?(400 ?m?t1?d).

Abstract: A diffractive optical device comprising: a base substrate; a resin layer having consecutively formed grating grooves and ridges, the resin layer being provided on a surface of the base substrate and being formed of a resin including a photo-curing resin or a thermosetting resin; and a side-surface resin layer. The side-surface resin layer is formed continuously with the resin layer and on a side surface of the base substrate so as to intersect end portions of the grating grooves and ridges, the side-surface resin layer being formed of a resin, which is a same material as that which forms the resin layer. An average thickness of the side-surface resin layer is greater than or equal to 0.1 ?m and less than or equal to 35 ?m. An endoscopic probe including the diffractive optical device, and a method of fabricating such device are disclosed.

Abstract: A diffractive optical element prevents degradation of the optical performance of the element due to moisture absorption of the resin layers from taking place and also can prevent cracks of the resin layers and peeling of the resin layers along the interface thereof from taking place in a hot environment or in a cold environment. The diffractive optical element comprises a first layer and a second layer sequentially laid on a substrate, a diffraction grating being formed at the interface of the first layer and the second layer, the height d of the diffraction grating, the average film thickness t1 of the first layer and the average film thickness t2 of the second layer satisfying the relationship requirements expressed by the expressions of 1.1×d?t1?50 ?m and 30 ?m?t2?(400 ?m?t1?d).

Abstract: A diffractive optical element prevents degradation of the optical performance of the element due to moisture absorption of the resin layers from taking place and also can prevent cracks of the resin layers and peeling of the resin layers along the interface thereof from taking place in a hot environment or in a cold environment. The diffractive optical element comprises a first layer and a second layer sequentially laid on a substrate, a diffraction grating being formed at the interface of the first layer and the second layer, the height d of the diffraction grating, the average film thickness t1 of the first layer and the average film thickness t2 of the second layer satisfying the relationship requirements expressed by the expressions of 1.1×d?t1?50 ?m and 30 ?m?t2?(400 ?m?t1?d).

Abstract: A diffractive optical element prevents degradation of the optical performance of the element due to moisture absorption of the resin layers from taking place and also can prevent cracks of the resin layers and peeling of the resin layers along the interface thereof from taking place in a hot environment or in a cold environment. The diffractive optical element comprises a first layer and a second layer sequentially laid on a substrate, a diffraction grating being formed at the interface of the first layer and the second layer, the height d of the diffraction grating, the average film thickness t1 of the first layer and the average film thickness t2 of the second layer satisfying the relationship requirements expressed by the expressions of 1.1×d?t1?50 ?m and 30 ?m?t2?(400 ?m?t1?d).

Abstract: A multilayer diffractive optical element includes a first substrate, a second substrate, a first resin layer having a first diffraction grating pattern and interposed between the first substrate and the second substrate, and a second resin layer having a second diffraction grating pattern and interposed between the first substrate and the second substrate. The first resin layer includes a first region provided at a peripheral portion adjacent to a portion of the first diffraction grating pattern. The first resin layer includes a second region provided at a peripheral portion adjacent to the first region.

Abstract: A laminated diffraction optical element includes a substrate, and a resin layer provided on the substrate and including an optically effective portion and an optically non-effective outer portion adjacent to the optically effective portion. The optically non-effective outer portion in the resin layer has a continuous shape such that a layer thickness decreases when extending toward an outer periphery of the substrate. An angle formed between a straight line connecting both ends of the continuous shape and a tangent to a surface of the substrate at a point opposite to an end closer to the surface of the substrate is within a range of 20 to 60 degrees.

Abstract: A multilayer diffractive optical element includes a first substrate, a second substrate, a first resin layer having a first diffraction grating pattern and interposed between the first substrate and the second substrate, and a second resin layer having a second diffraction grating pattern and interposed between the first substrate and the second substrate. The first resin layer includes a first region provided at a peripheral portion adjacent to a portion of the first diffraction grating pattern. The first resin layer includes a second region provided at a peripheral portion adjacent to the first region.

Abstract: A laminated diffraction optical element includes a substrate, and a resin layer provided on the substrate and including an optically effective portion and an optically non-effective outer portion adjacent to the optically effective portion. The optically non-effective outer portion in the resin layer has a continuous shape such that a layer thickness decreases when extending toward an outer periphery of the substrate. An angle formed between a straight line connecting both ends of the continuous shape and a tangent to a surface of the substrate at a point opposite to an end closer to the surface of the substrate is within a range of 20 to 60 degrees.