Angular aperture

About: Angular aperture is a research topic. Over the lifetime, 1771 publications have been published within this topic receiving 27257 citations.

Ultra wide angle imaging optical system, ultra wide angle imaging lens device, and image sensing apparatus

Abstract: An ultra wide angle imaging optical system includes, in order from an object side, a first lens group, an aperture stop, and a second lens group. The first lens group includes, in order from the position closest to the object side, a negative meniscus lens element convex to the object side, a negative lens element, and a negative lens element. The second lens group includes a plurality of positive lens elements. The first lens group and the second lens group each includes at least one anamorphic surface having different optical powers with respect to a first section extending in a first direction on a flat plane substantially orthogonal to an optical axis, and with respect to a second section extending in a second direction substantially orthogonal to the first direction. The first lens group includes the lens element satisfying the following conditional formula (1): −0.6<(Ph−Pv)*(fh+fv)<−0.1 (1) where Ph: an optical power in the first direction where a viewing angle is large; Pv: an optical power in the second direction where the viewing angle is small; fh: a focal length in the first direction with respect to the entirety of the optical system; and fv: a focal length in the second direction with respect to the entirety of the optical system.

Widely tunable optical parametric oscillator in a 5 mm thick 5% MgO:PPLN partial cylinder

Abstract: A 5 mm thick and 38 mm long 5% MgO-doped periodically poled lithium niobate (MgO:PPLN) cylinder with a grating period of 28 μm has been engineered as a partial cylinder with an angular aperture of 45°. An optical parametric oscillator based on this crystal and pumped at 1.064 μm is reported. The output energy is comparable to that generated in the same kind of sample cut as a slab, but the wavelength tunability from 1.41 to 4.3 μm is much broader and continuous.

Zoom lens having image stabilizing function

Abstract: A zoom lens comprises a plurality of lens units, in which at least one of lens unit separations in the plurality of lens units is varied to vary a focal length, an aperture stop, and a variable angle prism unit disposed on an image side of the aperture stop and having an apex angle varied to refract light, the zoom lens satisfying the following conditions: 1.16

Birefringent polarization prism with a large angular aperture

Abstract: An apparatus for polarizing natural light incident on a polarizer with an intermediate layer of one birefringent or biaxial material mounted between a pair of prism substrates of a second birefringent or biaxial material with a liquid or other index matching medium between the prism substrates and the intermediate layer to provide optical coupling between the three above-mentioned constituent parts of the prism. The materials of the prism substrates and of the intermediate layer being selected to be substantially transparent and to have orthogonal indices of refraction (n o and n e for birefringent materials and any two of n a , n b and n c for biaxial materials) which are considerably different for each individual material over the spectral region of the desired polarization. Further, the material of the intermediate layer is selected such that its greatest index of refraction curve is substantially equal to the lowest index of refraction curve of the material of the prism substrates over the spectral region of the desired polarization, and the optic axes of these materials are oriented in the assembled prism so that one constituent electric field component of the incident light experiences these matched indices of refraction. In addition, the liquid or other index matching medium is selected to have an index of refraction which is also substantially equal to the two matched indices of the prism materials. The single intermediate layer may be replaced with a sandwich of a plurality of intermediate layers. The composition of the plurality of intermediate layers alternates between the first and second birefringent or biaxial material with the outer layers being constructed from the second birefringent or biaxial material. In addition, the liquid or other index matching medium is used between each of this plurality of intermediate layers to provide optical coupling between each layer and the prism substrates. This prism configuration with a single or plurality of intermediate layers and the technique for choosing the prism materials provides the large angular aperture and, with the proper choice of materials, is operable substantially over the infrared, visible and ultraviolet spectrums.