An iris image acquisition system comprises an image sensor comprising an array of pixels including pixels sensitive to NIR wavelengths; at least one NIR light source capable of selectively emitting light with different discrete NIR wavelengths; and a processor, operably connected to the image sensor and the at least one NIR light source, to acquire image information from the sensor under illumination at one of the different discrete NIR wavelengths. A lens assembly comprises a plurality of lens elements with a total track length no more than 4.7 mm, each lens element comprising a material with a refractive index inversely proportional to wavelength. The different discrete NIR wavelengths are matched with the refractive index of the material for the lens elements to balance axial image shift induced by a change in object distance with axial image shift due to change in illumination wavelength.

An optical imaging system includes a first lens having a positive refractive power and a concave object-side surface, a second lens having a positive refractive power, a third lens having a negative refractive power, a fourth lens having a positive refractive power, and a fifth lens having a positive refractive power and a concave image-side surface. The first through fifth lenses are sequentially disposed in ascending numerical order from an object side of the optical imaging system toward an imaging plane of the optical imaging system.

Systems and methods according to one or more embodiments are provided for annealing a chalcogenide lens at an elevated temperature to accelerate release of internal stress within the chalcogenide lens caused during a molding process that formed the chalcogenide lens. In particular, the annealing process includes gradually heating the chalcogenide lens to a dwell temperature, maintaining the chalcogenide lens at the dwell temperature for a predetermined period of time, and gradually cooling the chalcogenide lens from the dwell temperature. The annealing process stabilizes the shape, the effective focal length, and/or the modulation transfer function of the chalcogenide lens. Associated optical assemblies and infrared imaging devices are also described.

The present disclosure provides a camera lens including six lenses, having good optical characteristics under near-infrared light and having a bright F number. The camera lens includes, from an object side: a first lens having a positive refractive power; a second lens having a negative refractive power; a third lens having a positive refractive power; a fourth lens having a positive refractive power; a fifth lens having a negative refractive power; and a sixth lens having a positive refractive power. The camera lens satisfies prescribed conditions.

A four-piece infrared single wavelength lens system includes, in order from the object side to the image side: a stop, a first lens element with a refractive power having an object-side surface being convex near an optical axis, a second lens element with a positive refractive power, a third lens element with a positive refractive power having an object-side surface being concave near the optical axis and an image-side surface being convex near the optical axis, a fourth lens element with a negative refractive power having an object-side surface being convex near the optical axis and an image-side surface being concave near the optical axis. Such arrangements can provide a four-piece infrared single wavelength lens system which has a wide field of view, large stop, short length and less distortion.

An optical imaging system includes a first lens, as second lens, a third lens, a fourth lens, and a fifth lens. The first lens includes a positive refractive power and a convex image-side surface. The second lens includes a positive refractive power, and the third lens includes a negative refractive power. The fourth lens includes a positive refractive power, and the fifth lens includes a positive refractive power. The first to fifth lenses are sequentially disposed from an object side toward an imaging plane.

A combined optical lens module and an optical imaging device with the combined optical lens module are provided. The optical imaging device includes a visible light-emitting unit, an invisible light-emitting unit, at least one visible light lens group and at least one invisible light lens group. After a visible light beam is transmitted through the at least one visible light lens group, a propagating direction of the visible light beam is changed. After an invisible light beam is transmitted through the at least one invisible light lens group, a propagating direction of the invisible light beam is changed.

An imaging lens is constituted by, in order from the object side to the image side: a positive first lens group; a stop; a negative second lens group; and a positive third lens group. Only the second lens group moves in the direction of the optical axis to perform focusing operations. The second lens group is constituted by one or two positive lenses and one negative lens. The third lens group is constituted by, in order from the object side to the image side, two or three positive lenses and one negative lens.

An optical image capturing system includes, along the optical axis in order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. At least one lens among the first to the sixth lenses has positive refractive force. The seventh lens have negative refractive force, wherein both surfaces thereof can be aspheric, and at least one surface thereof has an inflection point. The lenses in the optical image capturing system which have refractive power include the first to the seventh lenses. The optical image capturing system can increase aperture value and improve the imagining quality for use in compact cameras.

An optical image capturing system includes, along the optical axis in order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. At least one lens among the first to the sixth lenses has positive refractive force. The seventh lens can have negative refractive force, wherein both surfaces thereof are aspheric, and at least one surface thereof has an inflection point. The lenses in the optical image capturing system which have refractive power include the first to the seventh lenses. The optical image capturing system can increase aperture value and improve the imaging quality for use in compact cameras.