Showing papers on "Apochromat published in 2020"
20 Aug 2020
TL;DR: In this article, a color-selective geometric phase lens (CS-GPL) is proposed to mitigate the chromatic abberation in the AR/VR/MR lens system.
Abstract: Thin lenses have potentially much lower weight and volume than traditional refractive lenses, and therefore enable compelling solutions in augmented-/virtual-/mixed-reality (AR/VR/MR) headsets. The geometric-phase lens (GPL), formed either with liquid crystals (LCs) or metasurfaces, is emerging as a leading technology because of its ability to implement arbitrary aspherical phase profiles and its potential for low loss and minimal ghosting. However, a strong chromatic dispersion is inherent to each singlet. One prior method to overcome this employs a stack of multiple achromatic GPLs acting on all colors simultaneously with color filters and other waveplates to achieve an apochromatic lens system. Another concept in the prior art is to use multiple color-selective GPLs (CS-GPLs) wherein each diffracts only a single color while transmitting the others. In this work, we report on a family of color-selective GPLs with highly chromatic efficiency spectra, made using multi-twist LC coatings. In both theory and experiment, we show the diffraction efficiency of red, green, and blue lenses is high (< 91%) while the complementary colors of each coating are almost fully transmitted undiffracted. The CS-GPLs is a promising optical element to provide a new route to mitigate the chromatic abberation in the AR/VR/MR lens system.
4 citations
TL;DR: In this paper, measurements of the absolute sensitivity of three different optical cameras were presented, and an absolutely calibrated tungsten strip-lamp was used for calibrating the devices, and the results with five bandpass filters between 337nm and 740nm were shown.
Abstract: Measurements of the absolute sensitivity of three different optical cameras are presented. An absolutely calibrated tungsten strip-lamp was used for calibrating the devices. An experimental method for determining the solid angle which is accepted by the combination of the cameras with a broadband apochromatic lens is described. The results with five bandpass filters between 337nm and 740nm are shown. The signal to noise ratio and the spatial resolution of the camera systems is also discussed.
3 citations
Patent•
14 Apr 2020TL;DR: In this paper, a compact orthoscopic lens is corrected for monochromatic and chromatic aberrations over wavelengths from 450 to 2450 nm with an angular FOV of 5.56° vertical and 66° horizontal.
Abstract: A compact orthoscopic lens is corrected for monochromatic and chromatic aberrations over wavelengths from 450 to 2450 nm with an angular FOV of 5.56° vertical and 66° horizontal. The 4.36″ effective focal length lens with f-number of 4 is compact measuring 5.2″ from the first optical surface to the image. The lens includes, in order from object to image, a first optical group having a negative optical power; a second optical group having a positive optical power and a third optical group having a negative optical power. The first optical group consists of two elements, the second optical group consists of three elements, one a doublet, and the third optical group consists of two elements. A physical aperture stop is positioned inside the second optical group. Powers of groups and elements, shapes, refractive indices, Abbe numbers and partial dispersions of glasses are selected so the lens is apochromatic and orthoscopic.
1 citations
Patent•
08 May 2020
TL;DR: In this paper, an optical system of a high-zoom-ratio continuous zooming stereoscopic microscope is presented, which is characterized by sequentially comprising a first lens group G1 with a combined focal length of 90mm, a second lens groups G2 with a combination of 90.3 mm, a third lens group g3 with a combining focal length -31 mm, four lens groups g4 with a collection of 50.8 mm, five lens groupsg5 with a cumulative focal length-42 mm, six lens groupg6 with a composite focal length
Abstract: The invention discloses an optical system of a high-zoom-ratio continuous zooming stereoscopic microscope. The optical system is characterized by sequentially comprising a first lens group G1 with a combined focal length of 90mm, a second lens group G2 with a combined focal length of 90.3 mm, a third lens group G3 with a combined focal length of -31 mm, a fourth lens group G4 with a combined focallength of 50.8 mm, a fifth lens group G5 with a combined focal length of -42 mm, a sixth lens group G6 with a combined focal length of 189.5 mm, and a seventh lens group G7 with a combined focal length of 212mm from an object plane to an image plane in an optical axis direction, wherein the total length of the optical system is 501.6 mm. The optical system has the advantages that the multiplyingpower of the system is continuously adjustable in a large range and the zoom ratio is high on the premise of not including the magnification of an eyepiece, the image surface is kept stable, the imagequality is good, the aberration correction is balanced in the whole zoom process, and the apochromatic effect is achieved; the requirement of a user for additionally arranging accessories such as fluorescent accessories can be met; and the effects of simplifying the mechanical structure and being small in boundary dimension are achieved on the premise that various requirements are met, and transportation and user operation are facilitated.