scholarly journals Design and Implementation of a Semi-Reflective Plate Operating in the Visible and near Infrared Fields, with Reflection Coefficient Robust to the Light Wavelength and Angle of Incidence

2021 ◽  
pp. 1-5
Author(s):  
Mohammad Saeed Marouf ◽  
Keyword(s):  
Optical Communication ◽  
Light Field ◽  
Near Infrared ◽  
Optical Measurement ◽  
Extinction Ratio ◽  
Optical Measurements ◽  
Angle Of Incidence ◽  
Light Wavelength ◽  
Laser Technology ◽  
Transmission Coefficients

This research illustrates the design of a parallel plate reflector operating in the visible and near infrared fields, with a reflection and/or transmission coefficients equal to 50%, and robust to the polarization of the used light and its extinction ratio (PER), in each of the two directions of polarization (perpendicular S and parallel P). Also there is no need for accurate adjustment of the plate so that the angle of incidence is exactly equal to 45°. The research has its various applications in optical measurements laboratories, laser technology laboratories, optical communication laboratories, and photography. One of the most important applications of this plate is ophthalmology devices, which can be used as glasses for people with impaired vision, light measurements in laser laboratories and optical measurements. Purpose of the Research: The need for the use of one semi-reflector plate for all the visible and near infrared fields, instead of using one for each wavelength or light field, which will reduce the number of needed optical pieces used in the optical measurement and laser technology laboratories, because of its wide applications.

scholarly journals Noncontact Optical Measurement of Aqueous Humor Glucose Levels and Correlation with Serum Glucose Levels in Rabbit

Biosensors ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 387
Author(s):  
Yih-Shiou Hwang ◽  
Eugene Yu-Chuan Kang ◽  
Chia-Rui Shen ◽  
Wei-Hsin Hong ◽  
Wei-Chi Wu
Keyword(s):  
Aqueous Humor ◽  
Optical System ◽  
Near Infrared ◽  
Optical Measurement ◽  
Serum Glucose ◽  
Mean Difference ◽  
Optical Measurements ◽  
Glucose Levels

The noninvasive measurement of serum glucose levels has been investigated for the monitoring of blood sugar control in diabetes. In our study, we aimed to develop a novel noncontact glucometer (NCGM) utilizing an optical approach to measure the intraocular aqueous humor glucose levels in the anterior chamber of rabbit eyes. The NCGM consists of a hybrid optical system that simultaneously measures near-infrared absorption and the polarized rotatory distribution of glucose molecules in the aqueous humor. In vitro optical measurements demonstrated that NCGM measurements had high precision and repeatability for different glucose levels, including 50 mg/dL (14.36%), 100 mg/dL (−4.05%), 200 mg/dL (−5.99%), 300 mg/dL (4.86%), 400 mg/dL (−2.84%), 500 mg/dL (−0.11%), and 600 mg/dL (4.48%). In the rabbit experiments, we found a high correlation between aqueous glucose levels and serum glucose levels, with a mean difference of 8 mg/dL. According to the testing results, the in vivo NCGM measurement of aqueous humor glucose levels also displayed a high correlation with serum glucose levels, with a mean difference of 29.2 mg/dL. In conclusion, aqueous humor glucose levels were accurately measured using the NCGM, and the results correlated with serum glucose levels.

scholarly journals Upconversion Spectral Rulers for Transcutaneous Displacement Measurements

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3554
Author(s):  
Melissa M. Suckey ◽  
Donald W. Benza ◽  
John D. DesJardins ◽  
Jeffrey N. Anker
Keyword(s):  
Optical Measurement ◽  
Optical Measurements ◽  
Small Displacement ◽  
Simple Method ◽  
Low Background ◽  
X Ray ◽  
Optical Displacement ◽  
Spectral Peaks ◽  
Displacement Measurements ◽  
Minimal Intensity

We describe a method to measure micron to millimeter displacement through tissue using an upconversion spectral ruler. Measuring stiffness (displacement under load) in muscles, bones, ligaments, and tendons is important for studying and monitoring healing of injuries. Optical displacement measurements are useful because they are sensitive and noninvasive. Optical measurements through tissue must use spectral rather than imaging approaches because optical scattering in the tissue blurs the image with a point spread function typically around the depth of the tissue. Additionally, the optical measurement should have low background and minimal intensity dependence. Previously, we demonstrated a spectral encoder using either X-ray luminescence or fluorescence, but the X-ray luminescence required an expensive X-ray source and used ionizing radiation, while the fluorescence sensor suffered from interference from autofluorescence. Here, we used upconversion, which can be provided with a simple fiber-coupled spectrometer with essentially autofluorescence-free signals. The upconversion phosphors provide a low background signal, and the use of closely spaced spectral peaks minimizes spectral distortion from the tissue. The small displacement noise level (precision) through tissue was 2 µm when using a microscope-coupled spectrometer to collect light. We also showed proof of principle for measuring strain on a tendon mimic. The approach provides a simple method to study biomechanics using implantable sensors.

Electro-Optic Properties of (100)-Oriented (Pb,La(Zr,Ti)O3 Thin Film

2012 ◽  
Vol 185 ◽  
pp. 60-64
Author(s):  
Min Min Zhu ◽  
Ze Hui Du ◽  
Jan Ma
Keyword(s):  
Thin Films ◽  
Near Infrared ◽  
Infrared Light ◽  
Single Crystal Substrate ◽  
Light Wavelength ◽  
Prism Coupler ◽  
Electro Optic ◽  
Crystal Substrate ◽  
Tm Model ◽  
Plzt Thin Films

(100)-oriented PLZT ((Pb1-x, Lax) (Zry,Ti1-y)1-x/4O3, x/y=9/65) films of up to ~ 1.23 μm have been developed on LaAlO3single crystal substrate by magnetron sputtering. The as-grown PLZT thin films exhibit high optical transparency in visible and near-infrared light wavelength and high quadratic (Kerr) EO coefficients. Prism coupler measurements reveal that the PLZT thin films possess large refractive index, as high as 2.524 in TE model and 2.481 in TM model. The transparency of >70% in the range of λ= 500-1200 nm, the optic band gap of 3.42 eV and the quadratic electro-optic (EO) coefficient of 3.38 x 10-17(m/V)2have been measured in the films. Due to the large EO coefficient and the micrometric thickness, the as-developed PLZT films have great potential in developing longitudinal-or transverse-type EO devices in electric and optic field

Numerical Study of Near-Infrared Photodetectors with Surface-Plasmon Antenna for Optical Communication

2008 ◽  
Vol 47 (4) ◽  
pp. 2921-2923 ◽  
Author(s):  
Daisuke Okamoto ◽  
Junichi Fujikata ◽  
Kenichi Nishi ◽  
Keishi Ohashi
Keyword(s):  
Surface Plasmon ◽  
Optical Communication ◽  
Near Infrared ◽  
Numerical Study ◽  
Infrared Photodetectors

scholarly journals Multi-layered tissue head phantoms for noninvasive optical diagnostics

2015 ◽  
Vol 08 (03) ◽  
pp. 1541005 ◽  
Author(s):  
M. S. Wróbel ◽  
A. P. Popov ◽  
A. V. Bykov ◽  
M. Kinnunen ◽  
M. Jędrzejewska-Szczerska ◽  
...  
Keyword(s):  
Optical Properties ◽  
Near Infrared ◽  
Optical Measurement ◽  
Human Head ◽  
Medical Diagnostics ◽  
Optical Parameters ◽  
Measurement Systems ◽  
Tissue Phantoms ◽  
Optical And Mechanical Properties

Extensive research in the area of optical sensing for medical diagnostics requires development of tissue phantoms with optical properties similar to those of living human tissues. Development and improvement of in vivo optical measurement systems requires the use of stable tissue phantoms with known characteristics, which are mainly used for calibration of such systems and testing their performance over time. Optical and mechanical properties of phantoms depend on their purpose. Nevertheless, they must accurately simulate specific tissues they are supposed to mimic. Many tissues and organs including head possess a multi-layered structure, with specific optical properties of each layer. However, such a structure is not always addressed in the present-day phantoms. In this paper, we focus on the development of a plain-parallel multi-layered phantom with optical properties (reduced scattering coefficient [Formula: see text] and absorption coefficient μa) corresponding to the human head layers, such as skin, skull, and gray and white matter of the brain tissue. The phantom is intended for use in noninvasive diffuse near-infrared spectroscopy (NIRS) of human brain. Optical parameters of the fabricated phantoms are reconstructed using spectrophotometry and inverse adding-doubling calculation method. The results show that polyvinyl chloride-plastisol (PVCP) and zinc oxide ( ZnO ) nanoparticles are suitable materials for fabrication of tissue mimicking phantoms with controlled scattering properties. Good matching was found between optical properties of phantoms and the corresponding values found in the literature.

scholarly journals Methods of Assessing Milk Proteins Coagulation as a Part of the Forecasting System of Technological Properties

2021 ◽  
pp. 503-519
Author(s):  
Elena Illarionova ◽  
Alexandr Kruchinin ◽  
Svetlana Turovskaya ◽  
Alana Bigaeva
Keyword(s):  
Near Infrared ◽  
Milk Proteins ◽  
Raw Milk ◽  
Optical Measurements ◽  
Integrated Monitoring ◽  
Milk Clotting ◽  
Advantages And Disadvantages ◽  
Rennet Coagulation ◽  
Instrumental Methods ◽  
Instrumental Approaches

Introduction. An integrated monitoring of raw milk’s contents, quality, and security is a key factor that guarantees the high-quality dairy production. As a result, new research methods of rennet clotting are a topical and urgent area of study. The research objective was to systemize and analyze the basic criteria and assessment methods of rennet-induced protein gels in milk systems. Study objects and methods. The authors reviewed the official Russian criteria and methods of raw milk assessment by its rennet coagulation properties. The research also featured the most widespread instrumental approaches used in best practices from around the world. Results and discussion. In Russian and foreign cheese production, milk is always tested for its physicochemical and microbiological indicators, with a mandatory check of its coagulation characteristics. Russian cheese-makers use different modifications of rennet and rennet-fermenting tests based on subjective sensory evaluation, while international scientific trends in this area aim at developing and improving instrumental methods by using a complex indicator MCP. This indicator characterizes the parameters of rennet coagulation with the help of such devices as Formagraph, Lattodinamografo, Optigraph, etc. Formagraph is a simple instrument for measuring rheological properties of milk clotting. It was popular in the late XX century. The resent years saw the development of other methods of instrumental control, including those based on optical measurements. For instance, Ortigraph is one such instrument that receives unified data on coagulation properties of raw milk by using near-infrared waves. Sensory and instrumental methods have their advantages and disadvantages. However, the most significant criteria for a quick test of cheeseability, yield, and quality are the speed of analysis and the comparability and reproducibility of results. Conclusion. To improve cheeseability testing, Russian cheese-makers need to use the international experience, which offers standardized evaluation criteria in combination with various instrumental approaches. However, the integration of foreign regulations and methods into Russian studies is not the only option. The improvement and development of national instrumental methods of evaluating milk protein coagulation is also crucial.

scholarly journals Wide-angle near infrared polarizer with extremely high extinction ratio

2013 ◽  
Vol 21 (9) ◽  
pp. 10502 ◽  
Author(s):  
X. L. Liu ◽  
B. Zhao ◽  
Z. M. Zhang
Keyword(s):  
Near Infrared ◽  
Extinction Ratio ◽  
Wide Angle ◽  
High Extinction Ratio

scholarly journals Recent Advances on Metal-Based Near-Infrared and Infrared Emitting OLEDs

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1412 ◽  
Author(s):  
Malika Ibrahim-Ouali ◽  
Frédéric Dumur
Keyword(s):  
Metal Complexes ◽  
Optical Communication ◽  
Near Infrared ◽  
Infrared Region ◽  
Infrared Emission ◽  
Organic Light Emitting Diodes ◽  
Triplet States ◽  
Light Emitting ◽  
The Past ◽  
Organic Light

During the past decades, the development of emissive materials for organic light-emitting diodes (OLEDs) in infrared region has focused the interest of numerous research groups as these devices can find interest in applications ranging from optical communication to defense. To date, metal complexes have been most widely studied to elaborate near-infrared (NIR) emitters due to their low energy emissive triplet states and their facile access. In this review, an overview of the different metal complexes used in OLEDs and enabling to get an infrared emission is provided.

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