The Structure of the Cornea as Revealed by Polarized Light

1953 ◽  
Vol s3-94 (25) ◽  
pp. 83-88
Author(s):  
E. J. NAYLOR
Keyword(s):  
Refractive Index ◽  
Polarized Light ◽  
Preferential Orientation ◽  
Positive Sign ◽  
Immersion Technique ◽  
Intrinsic Birefringence

Studies of corneal sections in polarized light indicate that there are about 100 lamellae in the cat cornea; the coefficient of fibre birefringence is 0.0030. No evidence was found of preferential orientation of fibre directions. Corneal disks examined by an immersion technique show that the cornea exhibits both form and intrinsic birefringence of positive sign with a micellar refractive index of 1.50-1.52. The values of both form and intrinsic birefringence in various fixatives can be explained on the basis of swelling, which is both inter- and intra-micellar. The micellar volume according to the Wiener relationships does not exceed 3 per cent.; possible causes of this are discussed.

Light microscopy of ceramics

1993 ◽  
Vol 51 ◽  
pp. 908-909
Author(s):  
Walter C. McCrone
Keyword(s):  
Refractive Index ◽  
Light Microscopy ◽  
Light Microscope ◽  
Polarized Light ◽  
Refractive Indices ◽  
Complete Coverage ◽  
The Subject ◽  
Lower Refractive Index

An excellent chapter on this subject by V.D. Fréchette appeared in a book edited by L.L. Hench and R.W. Gould in 1971 (1). That chapter with the references cited there provides a very complete coverage of the subject. I will add a more complete coverage of an important polarized light microscope (PLM) technique developed more recently (2). Dispersion staining is based on refractive index and its variation with wavelength (dispersion of index). A particle of, say almandite, a garnet, has refractive indices of nF = 1.789 nm, nD = 1.780 nm and nC = 1.775 nm. A Cargille refractive index liquid having nD = 1.780 nm will have nF = 1.810 and nC = 1.768 nm. Almandite grains will disappear in that liquid when observed with a beam of 589 nm light (D-line), but it will have a lower refractive index than that liquid with 486 nm light (F-line), and a higher index than that liquid with 656 nm light (C-line).

High Polaried Transmission Effects for Double-Layer Metallic Grating Films on GaN Substrate

2011 ◽  
Vol 295-297 ◽  
pp. 1289-1293
Author(s):  
Bing Cao ◽  
Gui Ju Zhang ◽  
Qin Han ◽  
Chin Hua Wang ◽  
Jian Feng Wang ◽  
...  
Keyword(s):  
Refractive Index ◽  
Double Layer ◽  
Transition Layer ◽  
Light Transmission ◽  
Light Emitting Diode ◽  
Extinction Ratio ◽  
Polarized Light ◽  
Incident Wavelength ◽  
Metallic Grating ◽  
Low Refractive Index

Highly polarized light transmission from GaN based light emitting diode is proposed using a double-layer metallic grating film and a dielectric transition layer. TM mode transmission and the polarized extinction ratio (ER) are calculated using commercial software, based on a full vector implementation of Rigorous Coupled Wave Analysis (RCWA) algorithm. Such a thin-film double-layer grating with subwavelength metallic stripes are designed and simulated by perfect parameters of period, thickness and filling factor for achieving good polarization properties. It is found that TM transmission and ER are almost stable and flat under different slit arrays of the double-layer grating. The polarized structure shows larger width of incident wavelength with a transition layer of a low refractive index than that of a high refractive index, but higher TM transmission and ER can be obtained for low refractive index transition layer. Flat sensitivity and high transmission of the TM mode on the double-layer metal grating thickness have been achieved. Up to 100nm range of the grating height can be employed to achieve TM transmission more than 92% while ER> 20dB. The results provide guidance in designing, optimizing and fabricating the integrated GaN-based and polarized photonic devices.

Coherent, low-coherent, and polarized light interaction with tissues undergoing refractive-index matching control

1998 ◽  
Author(s):  
Valery V. Tuchin ◽  
Dmitry A. Zimnyakov ◽  
Irina L. Maksimova ◽  
Garif G. Akchurin ◽  
Alexey A. Mishin ◽  
...  
Keyword(s):  
Refractive Index ◽  
Polarized Light ◽  
Index Matching ◽  
Refractive Index Matching ◽  
Light Interaction

scholarly journals A Refractive Index Sensor Based on H-Shaped Photonic Crystal Fibers Coated with Ag-Graphene Layers

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 741 ◽  
Author(s):  
Tianshu Li ◽  
Lianqing Zhu ◽  
Xianchao Yang ◽  
Xiaoping Lou ◽  
Liandong Yu
Keyword(s):  
Refractive Index ◽  
Photonic Crystal ◽  
High Surface ◽  
Polarized Light ◽  
Pollution Monitoring ◽  
Confinement Loss ◽  
Silver Layer ◽  
Refractive Index Sensor ◽  
Graphene Layers ◽  
Wavelength Sensitivity

An Ag-graphene layers-coated H-shaped photonic crystal fiber (PCF) surface plasmon resonance (SPR) sensor with a U-shaped grooves open structure for refractive index (RI) sensing is proposed and numerically simulated by the finite element method (FEM). The designed sensor could solve the problems of air-holes material coating and analyte filling in PCF. Two big air-holes in the x-axis produce a birefringence phenomenon leading to the confinement loss and sensitivity of x-polarized light being much stronger than y-polarized. Graphene is deposited on the layer of silver in the grooves; its high surface to volume ratio and rich π conjugation make it a suitable dielectric layer for sensing. The effect of structure parameters such as air-holes size, U-shaped grooves depth, thickness of the silver layer and number of graphene layers on the sensing performance of the proposed sensor are numerical simulated. A large analyte RI range from 1.33 to 1.41 is calculated and the highest wavelength sensitivity is 12,600 nm/RIU. In the linear RI sensing region of 1.33 to 1.36; the average wavelength sensitivity we obtained can reach 2770 nm/RIU with a resolution of 3.61 × 10−5 RIU. This work provides a reference for developing a high-sensitivity; multi-parameter measurement sensor potentially useful for water pollution monitoring and biosensing in the future.

Improving the sensing performance of double gold gratings by oblique incident light

Nanoscale ◽  
2015 ◽  
Vol 7 (30) ◽  
pp. 13026-13032 ◽  
Author(s):  
Feifei Wu ◽  
Lingxiao Liu ◽  
Lei Feng ◽  
Daren Xu ◽  
Nan Lu
Keyword(s):  
Refractive Index ◽  
White Light ◽  
Incident Light ◽  
Polarized Light ◽  
Refractive Index Sensing ◽  
Sensing Applications ◽  
Sensing Performance

The refractive index sensing performance of double gold gratings can be improved by using the oblique incident light. And the application of white light instead of polarized light is beneficial to the sensing applications.

Sign in / Sign up

Export Citation Format

Share Document