A variable magnification optical system comprising, in order from an object side, a first lens group having negative refractive power, a first intermediate lens group having positive refractive power, a second intermediate lens group having negative refractive power and a rear lens group; upon varying a magnification from a wide angle end state to a telephoto end state, a distance between the first lens group and the first intermediate lens group being varied, a distance between the first intermediate lens group and the second intermediate lens group being varied, and a distance between the second intermediate lens group and the rear lens group being varied; the rear lens group comprising at least one focusing lens group which is moved upon carrying out focusing from an infinitely distant object to a closely distant object; and predetermined conditional expressions being satisfied, thereby the focusing lens group(s) being reduced in weight.

It is provided a lens unit to be small-sized, while reducing deterioration in optical performance after experiencing thermal expansion. The lens unit includes an aperture member, a lens, an image sensor, and a holder. A range where the aperture member abuts on a flange part of the lens overlaps with a range where the holder abuts on the flange part of the lens. A first gap is provided between a holder inclined surface of the holder and a lens inclined surface of the lens over the entire circumference. A second gap is provided between an outer circumferential surface of the lens and an inner surface of the holder over the entire circumference.

A non-linear optical pumping detection apparatus and a non-linear optical absorption cross-section measurement method, which can simultaneously measure degenerate and non-degenerate two-photon absorption cross-section spectra. The measurement process is automatic, efficient and fast. The working wavelength band is from 380 nm to near infrared 1064 nm, and the non-linear performance measurement of the super-continuous wide spectra can be realized. A zoom optical system with a larger entrance pupil diameter is adopted as a weak signal acquisition lens. So the weak signal can be effectively extracted from background noise. Meanwhile, the mean square root diameter of an on-axis image point of the zoom optical system is 100 to 150 microns, the divergence angle 2α of the on-axis image point is 30.6 degrees, which well match the optical fiber coupling condition, thereby improving the coupling efficiency of the space light coupling into the optical fiber, and greatly improving the measurement sensitivity.

A light blocking sheet includes a central opening and a plurality of light blocking structures. A central axis passes through the central opening. The light blocking structures surround an inner peripheral surface of the central opening, the light blocking structures are tapered and extended from the central opening towards a direction close to the central axis, and the light blocking structures are for defining a circumscribed circle and an inscribed circle, wherein a plurality of inscribed circle ends of the light blocking structures close to the central axis are contacted with the inscribed circle, and a plurality of circumscribed circle ends of the light blocking structures away from the central axis are contacted with the circumscribed circle.

An optical lens assembly includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, all of which are arranged in order from an object side to an image side along an optical axis. The first lens is a meniscus lens with positive refractive power. The second lens is with positive refractive power. The third lens is with negative refractive power. The fourth lens is with positive refractive power and includes a convex surface facing the image side. The fifth lens is with negative refractive power and includes a concave surface facing the object side. The sixth lens is with positive refractive power and includes a convex surface facing the image side.

A lens group is provided, which includes a first lens (L1), a second lens (L2), a third lens (L3), a fourth lens (L4), and a fifth lens (L5) that are sequentially arranged from an object side to an image side, and a relative refractive index temperature coefficient β of at least one lens meets: −9×10.sup.−5≤β≤9×10.sup.−5. A temperature drift coefficient of the lens group falls within a small range, a temperature effect of the lens group is low, and a defocus phenomenon generated because the lens group changes with a temperature is weak. According to the application, a design difficulty of a voice coil motor in a lens can be reduced and user experience is improved.

An imaging lens module includes at least one plastic lens element having an optical axis, an object side and an image side. The plastic lens element includes, in order from a center to a peripheral region thereof, an optical effective portion and an outer peripheral portion. The outer peripheral portion surrounds the optical effective portion, wherein the outer peripheral portion includes, on at least one of the object side and the image side, a plurality of groove structures and a contacting surface. The contacting surface is an annular plane and perpendicular to the optical axis. The groove structures and the contacting surface are located on the same side. There is an air gap between the groove structures and at least one optical element adjacent thereto. The groove structures and the contacting surface located on the same side are not overlapped along a direction parallel to the optical axis.

An optical system includes a lens layer including a plurality of microlenses arranged along orthogonal first and second directions, and at least one optically opaque mask layer spaced apart from the lens layer and defining a plurality of through openings therein arranged along the first and second directions. There is a one-to-one correspondence between the microlenses and the openings, such that for each microlens, the microlens and corresponding openings are substantially centered on a straight line making a same oblique angle with the lens layer. An optical layer can include the lens layer and the optically opaque mask layer embedded in the optical layer.

A display substrate, a method for forming a display substrate, and a display device are provided. The display substrate includes: a plurality of pixels arranged in an array on a base substrate; a light-shielding pattern at a side, away from the base substrate, of the pixels, and an orthographic projection of the light-shielding pattern on the base substrate is overlapped with an orthographic projection of a gap between adjacent pixels on the base substrate; a light extraction structure arranged at a light-emitting side of the pixel and a side of the light-shielding pattern adjacent to the base substrate, a light-emitting direction of the light extraction structure is a direction of the light extraction structure away from the pixels, and an orthographic projection of the light extraction structure on the base substrate is overlapped with an orthographic projection of the pixels on the base substrate.

An optical system for a virtual retinal scan display. The optical system includes: a projector unit including a modulatable light source for generating at least one modulated light beam and including a movable deflection device for the light beam, a scanning projection of an image content being generatable from the at least one light beam as a result of the movement of the movable deflection device; a diverting unit, onto which the image content is projectable and which is configured to map the projected image content into an exit pupil and to guide it onto an eye of a user; an optical exit pupil shifting unit situated in an optical path of the light beam for spatially shifting the exit pupil of an eye box of the optical system in directions which extend at least essentially in parallel to an exit pupil plane of the exit pupil.