Optoelectronic imaging equipment is easy to expose to active laser detection devices because of ＂cat eye＂ effect. In this paper, we propose a new structure of optical system to reduce the retroreflector effect of a ...Optoelectronic imaging equipment is easy to expose to active laser detection devices because of ＂cat eye＂ effect. In this paper, we propose a new structure of optical system to reduce the retroreflector effect of a cat eye target. Decentered field lens structure is adopted in the design without sacrificing imaging quality and clear aperture. An imaging system with±30° field of view is taken for example. The detailed design and simulation results are presented. The results indicate that this kind of optical system can reduce the retroreflection signal substantially and maintain acceptable imaging performance.展开更多
Infrared （IR） absorption spectra and X-ray powder diffraction （XRD） patterrns of sexpenfine cat＇s eye from Sichuan Province have been investigated, and infrared absorption bands of the serpentine have been assign...Infrared （IR） absorption spectra and X-ray powder diffraction （XRD） patterrns of sexpenfine cat＇s eye from Sichuan Province have been investigated, and infrared absorption bands of the serpentine have been assigned in this paper. The results indicate that the bands near 3 600 - 3 700 cm^-1 belong to the stretching absorption band VOH, the bands in 948 - 1 100 cm^-1 axe assigned to the stretching vibraling band Usvo, and the bands at 600 570 and 440 cm^-1 respectively belong to the bending vibration band VOH, δMg-O and δSi-O. The serpentine cat＇ s eye includes two types： chrysotile and antigorite. Chrysotile has a sharp and intensive band at 3 688 cm^-1 and a weak band at 3 643 cm^-1 , while antigorite has only one intensive band in the region. At vibration band VSi-O, chrysotile and antigorite have a similar feature at 1 071 cm^-1, but the band at 980 cm^-1 in anfigorite has been split into two bands in chrysotile - a strong one at 1 027 cm^-1 and a weak one at 949 cm^-1. In addition, antigorite has a characteristic bending vibrating band δMg-O at 570 cm^-1. Based on the analysis of the feature of crystal structure, their IR differences axe well explained.展开更多
The article describes 6 types of gemstones which show phenomena such as chatoyancy and asterism.The gemstones have not been described before,either because they come from new sources,or because the phenomenon has not ...The article describes 6 types of gemstones which show phenomena such as chatoyancy and asterism.The gemstones have not been described before,either because they come from new sources,or because the phenomenon has not been seen before in the type of gemstone described.Gems from the new sources are star garnet from the Karelia Province in Russia,and star garnet from the Jiangsu Province in China.Grandidierite usually does not show a cat’s eye effect,but the two described samples display a weak cat’s eye.An unusual white quartz from Brazil with a sharp cat’s eye is described,as well as a star sapphire with two differently coloured stars on each side of the cabochon,as well as a trapiche-type quartz.The stones were tested with gemmological,microscopic,and advanced techniques and the results are presented.展开更多
Long arm trisomy of chromosome 22 or cat eye syndrome （OMIM#115470） is a disease with an enormous variability of clinical features, ranging from minor malformations like hypertelorism, to major ones, as congenital h...Long arm trisomy of chromosome 22 or cat eye syndrome （OMIM#115470） is a disease with an enormous variability of clinical features, ranging from minor malformations like hypertelorism, to major ones, as congenital heart and renal disorders, combined with variable growth retardation. The authors report a case of a newborn female with clinical features of cat eye syndrome with trisomy 22 in inbred line, who died 35 days after birth. The clinical features at the time of diagnosis were： left preauricular appendix, low-set ears, hypertelorism, mongoloid palpebral apertures, right-sided microphthalmia, left-sided anophthalmia, cleft lip and palate, short neck, anomalous pulmonary venous return, severe lung hypertension, hyperechogenic little kidneys and clinodactyly of the fifth finger on the left side. Cerebral ultrasound showed dilatation of both lateral ventricles, with a callosum corpus difficult to evaluate. The cytogenetics diagnostic was made from peripheral blood by conventional cytogenetics techniques in two different laboratories, and confirmed by fluorescent in situ hybridization.展开更多
In this paper, we propose and demonstrate an adjustable-free and movable Nd:YVO_(4)thin disk laser based on the telecentric cat’s eye cavity. We design a V-shaped laser cavity containing two reflectors with Nd:YVO_(4...In this paper, we propose and demonstrate an adjustable-free and movable Nd:YVO_(4)thin disk laser based on the telecentric cat’s eye cavity. We design a V-shaped laser cavity containing two reflectors with Nd:YVO_(4)thin disks as the gain medium.The experimental results from the traditional plane-plane cavity, plane-telecentric cat’s eye cavity, and double telecentric cat’s eye cavity are compared. They show that plane-telecentric cat’s eye cavity laser can keep operating at the adjustablefree range of -6° to +6°, which is up to 60 times better than that of traditional plane-plane cavity. In the double telecentric cat’s eye case, the adjustable-free range is improved to-13° to +13°. Additionally, in the case of the double telecentric cat’s eye cavity, the output telecentric cat’s eye can achieve free movement within the horizontal range of ±20 mm.展开更多
It is well known that cats have fascinating eyes with various colors,such as green,blue,and brown.In addition,they possess strong night vision ability,which can distinguish things clearly even in a poor light environm...It is well known that cats have fascinating eyes with various colors,such as green,blue,and brown.In addition,they possess strong night vision ability,which can distinguish things clearly even in a poor light environment.These drive us to reveal the secrets behind them.In fact,cats’ eyes can be considered as special lenses(which we would like to mimic by using a Luneburg lens).We make an analysis of the role of photonic crystals behind the lens and demonstrate that the integration of photonic crystals into Luneburg lens can be regarded as a retroreflector and greatly improve the light focusing intensity of the lens in a broad band of frequencies.This wonderful bioinspired phenomenon is expected to design more interesting and serviceable devices by combining photonic crystals with transformation optics.展开更多
In order to achieve high-accuracy measurement of radius of curvature of optical sphere, ultra-high accuracy radius of curvature testing device is developed by dual-frequency laser interferometer and Fizeau interferome...In order to achieve high-accuracy measurement of radius of curvature of optical sphere, ultra-high accuracy radius of curvature testing device is developed by dual-frequency laser interferometer and Fizeau interferometer based on cat’s eye and confocal method. Through analyzing the error source models of radius of curvature testing, optical configuration of the testing device has been optimized. Precise environment control and real-time monitoring system is also established to reduce the errors caused by environment. Through the above processes, the radius of curvature measurement relative accuracy is better than 2 ppm. One optical sphere, R88.5 mm, test aperture 59 mm, has been tested. Testing result is 88499.465 ± 0.176 μm, meeting the design requirement. The method has high accuracy and practical advantages.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61471039)
文摘Optoelectronic imaging equipment is easy to expose to active laser detection devices because of ＂cat eye＂ effect. In this paper, we propose a new structure of optical system to reduce the retroreflector effect of a cat eye target. Decentered field lens structure is adopted in the design without sacrificing imaging quality and clear aperture. An imaging system with±30° field of view is taken for example. The detailed design and simulation results are presented. The results indicate that this kind of optical system can reduce the retroreflection signal substantially and maintain acceptable imaging performance.
文摘Infrared （IR） absorption spectra and X-ray powder diffraction （XRD） patterrns of sexpenfine cat＇s eye from Sichuan Province have been investigated, and infrared absorption bands of the serpentine have been assigned in this paper. The results indicate that the bands near 3 600 - 3 700 cm^-1 belong to the stretching absorption band VOH, the bands in 948 - 1 100 cm^-1 axe assigned to the stretching vibraling band Usvo, and the bands at 600 570 and 440 cm^-1 respectively belong to the bending vibration band VOH, δMg-O and δSi-O. The serpentine cat＇ s eye includes two types： chrysotile and antigorite. Chrysotile has a sharp and intensive band at 3 688 cm^-1 and a weak band at 3 643 cm^-1 , while antigorite has only one intensive band in the region. At vibration band VSi-O, chrysotile and antigorite have a similar feature at 1 071 cm^-1, but the band at 980 cm^-1 in anfigorite has been split into two bands in chrysotile - a strong one at 1 027 cm^-1 and a weak one at 949 cm^-1. In addition, antigorite has a characteristic bending vibrating band δMg-O at 570 cm^-1. Based on the analysis of the feature of crystal structure, their IR differences axe well explained.
文摘The article describes 6 types of gemstones which show phenomena such as chatoyancy and asterism.The gemstones have not been described before,either because they come from new sources,or because the phenomenon has not been seen before in the type of gemstone described.Gems from the new sources are star garnet from the Karelia Province in Russia,and star garnet from the Jiangsu Province in China.Grandidierite usually does not show a cat’s eye effect,but the two described samples display a weak cat’s eye.An unusual white quartz from Brazil with a sharp cat’s eye is described,as well as a star sapphire with two differently coloured stars on each side of the cabochon,as well as a trapiche-type quartz.The stones were tested with gemmological,microscopic,and advanced techniques and the results are presented.
文摘Long arm trisomy of chromosome 22 or cat eye syndrome （OMIM#115470） is a disease with an enormous variability of clinical features, ranging from minor malformations like hypertelorism, to major ones, as congenital heart and renal disorders, combined with variable growth retardation. The authors report a case of a newborn female with clinical features of cat eye syndrome with trisomy 22 in inbred line, who died 35 days after birth. The clinical features at the time of diagnosis were： left preauricular appendix, low-set ears, hypertelorism, mongoloid palpebral apertures, right-sided microphthalmia, left-sided anophthalmia, cleft lip and palate, short neck, anomalous pulmonary venous return, severe lung hypertension, hyperechogenic little kidneys and clinodactyly of the fifth finger on the left side. Cerebral ultrasound showed dilatation of both lateral ventricles, with a callosum corpus difficult to evaluate. The cytogenetics diagnostic was made from peripheral blood by conventional cytogenetics techniques in two different laboratories, and confirmed by fluorescent in situ hybridization.
基金This work was supported by the National Natural Science Foundation of China(NSFC)(Nos.61775223 and 11974367)Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB1603)Shanghai Science and Technology Innovation Action Plan Project(No.19142202500)。
文摘In this paper, we propose and demonstrate an adjustable-free and movable Nd:YVO_(4)thin disk laser based on the telecentric cat’s eye cavity. We design a V-shaped laser cavity containing two reflectors with Nd:YVO_(4)thin disks as the gain medium.The experimental results from the traditional plane-plane cavity, plane-telecentric cat’s eye cavity, and double telecentric cat’s eye cavity are compared. They show that plane-telecentric cat’s eye cavity laser can keep operating at the adjustablefree range of -6° to +6°, which is up to 60 times better than that of traditional plane-plane cavity. In the double telecentric cat’s eye case, the adjustable-free range is improved to-13° to +13°. Additionally, in the case of the double telecentric cat’s eye cavity, the output telecentric cat’s eye can achieve free movement within the horizontal range of ±20 mm.
基金supported by the National Key Research and Development Program of China (No. 2020YFA0710100)the National Science Foundation of China (Nos. 11874311 and 92050102)the Fundamental Research Funds for the Central Universities (No. 20720200074)
文摘It is well known that cats have fascinating eyes with various colors,such as green,blue,and brown.In addition,they possess strong night vision ability,which can distinguish things clearly even in a poor light environment.These drive us to reveal the secrets behind them.In fact,cats’ eyes can be considered as special lenses(which we would like to mimic by using a Luneburg lens).We make an analysis of the role of photonic crystals behind the lens and demonstrate that the integration of photonic crystals into Luneburg lens can be regarded as a retroreflector and greatly improve the light focusing intensity of the lens in a broad band of frequencies.This wonderful bioinspired phenomenon is expected to design more interesting and serviceable devices by combining photonic crystals with transformation optics.
文摘In order to achieve high-accuracy measurement of radius of curvature of optical sphere, ultra-high accuracy radius of curvature testing device is developed by dual-frequency laser interferometer and Fizeau interferometer based on cat’s eye and confocal method. Through analyzing the error source models of radius of curvature testing, optical configuration of the testing device has been optimized. Precise environment control and real-time monitoring system is also established to reduce the errors caused by environment. Through the above processes, the radius of curvature measurement relative accuracy is better than 2 ppm. One optical sphere, R88.5 mm, test aperture 59 mm, has been tested. Testing result is 88499.465 ± 0.176 μm, meeting the design requirement. The method has high accuracy and practical advantages.
