Abstract: A semiconductor laminate film includes a silicon substrate and a semiconductor layer formed on the silicon substrate and containing silicon and germanium. The semiconductor layer having a surface roughness Rms of 1 nm or less. Further, the semiconductor layer satisfies the following relationship t?0.881×x?4.79 where t represents a thickness (nm) of the semiconductor layer, and x represents a ratio of the number of germanium atoms to a sum of the number of silicon atoms and the number of germanium atoms in the semiconductor layer. Also, the semiconductor layer being a mixed crystal semiconductor layer containing silicon and germanium.

Abstract: There are provided a zoom lens which has a wide angle, maintains the brightness of an F-number, and has various aberrations excellently corrected, and an image pickup device having such zoom lens mounted thereon. A zoom lens 10 substantially includes a positive first lens group Gr1, a negative second lens group Gr2, a positive third lens group Gr3, a positive fourth lens group Gr4, and a fifth lens group Gr5 in order from an object side. At a time of magnification change from a wide-angle end to a telephoto end, the first lens group Gr1 and fifth lens group Gr5 are fixed, while the second lens group Gr2, the third lens group Gr3, and the fourth lens group Gr4 move, and the conditional expressions (1) and (2) are satisfied.

Abstract: There are provided a zoom lens which has a wide angle, maintains the brightness of an F-number, and has various aberrations excellently corrected, and an image pickup device having such zoom lens mounted thereon. A zoom lens 10 substantially includes a positive first lens group Gr1, a negative second lens group Gr2, a positive third lens group Gr3, a positive fourth lens group Gr4, and a fifth lens group Gr5 in order from an object side. At a time of magnification change from a wide-angle end to a telephoto end, the first lens group Gr1 and fifth lens group Gr5 are fixed, while the second lens group Gr2, the third lens group Gr3, and the fourth lens group Gr4 move, and the conditional expressions (1) and (2) are satisfied.

Abstract: Provided is a compact zoom lens with a high resolving power, a large aperture, and a high variable power. The zoom lens includes a positive first lens group, a moving negative second lens group, a stationary positive third lens group, and a moving positive fourth lens group. The first lens group includes a negative eleventh lens, a positive twelfth lens, and a positive thirteenth lens. The second lens group is composed of a negative twenty-first lens, a negative twenty-second lens, a positive twenty-third lens, and a negative twenty-fourth lens. The third lens group includes a positive thirty-first lens, a positive thirty-second lens, and a negative thirty-third lens. The fourth lens group is composed of a positive forty-first lens having one or more aspheric surfaces. The zoom lens satisfies the prescribed conditional expressions.

Abstract: Provided is a compact zoom lens with a high resolving power, a large aperture, and a high variable power. The zoom lens includes a positive first lens group, a moving negative second lens group, a stationary positive third lens group, and a moving positive fourth lens group. The first lens group includes a negative eleventh lens, a positive twelfth lens, and a positive thirteenth lens. The second lens group is composed of a negative twenty-first lens, a negative twenty-second lens, a positive twenty-third lens, and a negative twenty-fourth lens. The third lens group includes a positive thirty-first lens, a positive thirty-second lens, and a negative thirty-third lens. The fourth lens group is composed of a positive forty-first lens having one or more aspheric surfaces. The zoom lens satisfies the prescribed conditional expressions.

Abstract: A zoom lens includes in the order from an object a first lens group having a negative refractive power, including at least one negative lens and one positive lens, wherein a negative plastic lens having one or more aspherical surfaces is arranged on a side closest to the object; a second lens group having positive refractive power, including a first positive lens, a second positive lens and a negative lens in the order from the object; and a third lens group, wherein each lens group is moved in a direction of an optical axis for zooming, and the following expressions are satisfied: 2.0<|f1/fw|<3.0 1.2<|f1a/fw|<1.8 where f1, f1a and fw represent focal lengths of the first lens group, of the negative plastic lens arranged closest to the object, and at a wide-angle end of an entire zoom lens, respectively.

Abstract: A rear focus type zoom lens for an image capturing element, comprising, in the order from the object side: a first lens group having a positive refracting power; a second lens group having a negative refracting power and movable for variable magnification; a third lens group having a positive refracting power; and a fourth lens group having a positive refracting power and movable for correcting positional change of an image plane in variable magnification. When ?1 represents Abbe's number of at least one piece of positive lenses of the first lens group, ?31 represents Abbe's number of a single lens, fi represents a focal length of an ith lens group and f4? represents a focal length of the negative lens in the fourth lens group, the following conditional expressions are satisfied: 75.0<?1, 40.0>?31, 0.8<f4/|f4?|<1.5, 3.0<|f1/f2|<6.0.

Abstract: A zoom lens includes in the order from an object a first lens group having a negative refractive power, including at least one negative lens and one positive lens, wherein a negative plastic lens having one or more aspherical surfaces is arranged on a side closest to the object; a second lens group having positive refractive power, including a first positive lens, a second positive lens and a negative lens in the order from the object; and a third lens group, wherein each lens group is moved in a direction of an optical axis for zooming, and the following expressions are satisfied: 2.0<|f1/fw|<3.0 1.2<|f1a/fw|<1.8 where f1, f1a and fw represent focal lengths of the first lens group, of the negative plastic lens arranged closest to the object, and at a wide-angle end of an entire zoom lens, respectively.

Abstract: A rear focus type zoom lens for an image capturing element, comprising, in the order from the object side: a first lens group having a positive refracting power; a second lens group having a negative refracting power and movable for variable magnification; a third lens group having a positive refracting power; and a fourth lens group having a positive refracting power and movable for correcting positional change of an image plane in variable magnification. When v1 represents Abbe's number of at least one piece of positive lenses of the first lens group, v31 represents Abbe's number of a single lens, fi represents a focal length of an ith lens group and f4? represents a focal length of the negative lens in the fourth lens group, the following conditional expressions are satisfied. 75.0<v1, 40.0>v31, 0.8<f4/|f4?|<1.5, 3.0<|f1/f2|<6.