Abstract: There is provided an infrared light source that has a simple structure and radiates infrared rays polarized in a specific direction and having a specific wavelength. The infrared light source (100) comprises a heat generator (107) and a latticework (101) in which a dielectric part (105) and a metal part (103) are alternately formed at a constant pitch in a constant direction. The infrared rays are radiated in a direction perpendicular to the surface of the latticework and are polarized in the direction indicated by an arrow A. If the constant pitch is denoted by P, the width of the dielectric part in the constant direction by T, and the specific wavelength by ?, for arbitrary P and T that meet the inequalities 0<P?2.0 and T?0.5P, the depth D of the latticework is so selected that the intensity spectrum of the infrared rays radiated from the infrared light source has the peak at ?.

Abstract: An imaging optical system capable of moving a meridian image plane further closer to an ideal imaging plane vertical to an optical axis with the number of lenses kept constant. At least one plane of at least one optical element and including at least one optical element is divided into at least one zonal area surrounding an optical axis and a center area including the optical axis.

Abstract: This invention provides a mold with which a two-dimensional subwavelength grating can be produced with a higher percentage transfer by injection molding and a two-dimensional subwavelength grating having a high aspect ratio produced with such a mold. The mold for a fine grating according to the present invention has protrusion parts (107) arranged at an interval on the bottom face (103) of a cavity, wherein the interval is a distance between centers of the protrusion parts and a period of the fine grating smaller than wavelengths of visible lights. In one embodiment, a cross-section of the protrusion parts, parallel to the bottom face of the cavity decreases with height along the protrusion parts and a decreasing rate of the cross-section increases with height along the protrusions.

Abstract: An optical pickup records data in or reproduces data from optical recording media respectively having recording faces at different heights, and includes a semiconductor laser diode array having light emitting portions for respectively emitting laser beams of different wavelengths. A finite conjugate type object lens used in this optical pickup is designed so that the numerical aperture of the object lens can be controlled to be changed in accordance with switching between the different wavelengths for allowing a laser beam to be focused on each optical recording medium.

Abstract: An optical pickup having a light-emitting element, an objective lens unit, a reflecting mirror and a light-receiving element, emits a beam onto an optical recording medium and uses a reflected beam to read recorded information. In the objective lens unit, a central part of a surface, facing the light-emitting element, of an objective lens disposed so that an optical axis is substantially aligned with a chief ray of the beam emitted by the light-emitting element, is a transmissive diffraction grating, and a central part of a surface of the objective lens that will face the optical recording medium is a convex mirror which bulges toward the light-emitting element. The reflecting mirror, which is annular and encompasses the optical axis of the objective lens, reflects toward the objective lens the beam from the light-emitting element that has passed through the transmissive diffraction grating and been reflected by the convex mirror.

Abstract: The production method for an optical fiber connector includes the steps of: injecting and hardening a first resin (26) into a resin-injection portion (29) of a connector body (22), the first resin (26) being a light hardening resin or a heat hardening resin; forming a pre-lens by further injecting a second resin (27) on the hardened first resin (26), the second resin (27) being the light hardening resin or the heat hardening resin; and forming a lens by hardening the second resin (27). In this way, it is possible to provide a production method for an optical lens by which influences by volume shrinkage of a resin are decreased, a lens surface can be formed with high accuracy and the product can be made with high quality.

Abstract: An optical fiber connector (19) has a connector main body including a first pipe (20) for receiving a fiber (24) inside, and three second pipes (21a) through (21c) for receiving the first pipe (20) inside. With this arrangement, the fiber (24) can be securely held with ease at the center of the connector main body. On this account, it is possible to provide the optical fiber connector (19) in which the fiber (24) is securely held with ease at the center of the connector main body.

Abstract: An optical pickup records data in or reproduces data from optical recording media respectively having recording faces at different heights, and includes a semiconductor laser diode array having light emitting portions for respectively emitting laser beams of different wavelengths. A finite conjugate type object lens used in this optical pickup is designed so that the numerical aperture of the object lens can be controlled to be changed in accordance with switching between the different wavelengths for allowing a laser beam to be focused on each optical recording medium.