Source numerical aperture control for efficient light emission from notched side-lighting fiber optics

2004 ◽  
Author(s):  
Sheldon Sillyman ◽  
Kenneth K. Li ◽  
Seiji Inatsugu
Keyword(s):  
Fiber Optics ◽  
Light Emission ◽  
Numerical Aperture ◽  
Aperture Control

scholarly journals Dynamically controlled light delivery over large brain volumes through tapered optical fibers

2016 ◽  
Author(s):  
Ferruccio Pisanello ◽  
Gil Mandelbaum ◽  
Marco Pisanello ◽  
Ian A. Oldenburg ◽  
Leonardo Sileo ◽  
...  
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Light Emission ◽  
Motor Behavior ◽  
Numerical Aperture ◽  
Brain Volumes ◽  
Light Emitting ◽  
Precise Control ◽  
Neural Processes ◽  
Large Brain

ABSTRACTOptogenetics promises spatiotemporal precise control of neural processes using light. However, the spatial extent of illumination within the brain is difficult to control and cannot be adjusted using standard fiber optics. We demonstrate that optical fibers with tapered tips can be used to illuminate either large brain volumes or dynamically selectable subregions. Remotely adjusting the light input angle to the fiber varies the light-emitting portion of the taper over several millimeters without movement of the implant. We use this mode to activate dorsal versus ventral striatum of individual mice and reveal different effects of each manipulation on motor behavior. Conversely injecting light over the full numerical aperture of the fiber results in light emission from the entire taper surface, achieving broader and more efficient optogenetic activation of neurons when compared to the standard flat-faced fiber stimulation. Thus, tapered fibers permit focal or broad illumination that can be precisely and dynamically matched to experimental needs.

scholarly journals Shaping Beam Profiles Using Plastic Optical Fiber Tapers with Application to Ice Sensors

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2503
Author(s):  
Kostas Amoiropoulos ◽  
Georgia Kioselaki ◽  
Nikolaos Kourkoumelis ◽  
Aris Ikiades
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Laser Cooling ◽  
Detection Efficiency ◽  
Numerical Aperture ◽  
Beam Profile ◽  
Hollow Beam ◽  
Enhanced Sensitivity ◽  
Surface Irregularities ◽  
Plastic Optical Fibers

Using either bulk or fiber optics the profile of laser beams can be altered from Gaussian to top-hat or hollow beams allowing enhanced performance in applications like laser cooling, optical trapping, and fiber sensing. Here, we report a method based on multimode Plastic Optical Fibers (POF) long-tapers, to tweak the beam profile from near Gaussian to a hollow beam, by generating surface irregularities on the conical sections of the taper with a heat-and-pull technique. Furthermore, a cutback technique applied on long tapers expanded the output beam profile by more than twice the numerical aperture (NA) of the fiber. The enhanced sensitivity and detection efficiency of the extended profile was tested on a fiber optical ice sensor related to aviation safety.

scholarly journals Study of Optical Fiber Design Parameters in Fiber Optics Communications

2017 ◽  
Vol 2 (3) ◽  
pp. 302-308 ◽  
Author(s):  
Salim Qadir Mohammed ◽  
Asaad M. Asaad M. Al-Hindawi
Keyword(s):  
Optical Fiber ◽  
Fiber Optics ◽  
Numerical Aperture ◽  
Design Parameters ◽  
Light Sources ◽  
Long Distance ◽  
Graded Index ◽  
Large Bandwidth ◽  
Telecommunication Infrastructure ◽  
Distance Communication

Fiber optics is an important part in the telecommunication infrastructure. Large bandwidth and low attenuation are features for the fiber optics to provide gigabit transmission. Nowadays, fiber optics are used widely in long distance communication and networking to provide the required information traffic for multimedia applications. In this paper, the optical fiber structure and the operation mechanism for multimode and single modes are analyzed. The design parameters such as core radius, numerical aperture, attenuation, dispersion and information capacity for step index and graded index fibers are studied, calculated and compared for different light sources.

Uranium Determination by Remote Time-Resolved Laser-Induced Fluorescence

1993 ◽  
Vol 47 (12) ◽  
pp. 2007-2012 ◽  
Author(s):  
Christophe Moulin ◽  
Stephane Rougeault ◽  
Dominique Hamon ◽  
Patrick Mauchien
Keyword(s):  
Fiber Optics ◽  
Fuel Cycle ◽  
Numerical Aperture ◽  
Laser Induced Fluorescence ◽  
Time Resolved ◽  
Aperture Diameter ◽  
Current Trends ◽  
Remote Measurements ◽  
Excitation Laser ◽  
A Cell

Uranium measurements taken in a hostile environment are required in the nuclear fuel cycle. Current trends are leading toward development of better sensitivity and rapidity as well as remote measurements. Time-Resolved Laser-Induced Fluorescence (TRLIF) is a very selective and sensitive method that has been widely used for uranium determinations in complex matrices. This technique evolved from analysis in a cell located in a glove box to remote measurements via fiber optics in a shielded cell. The setup of Remote Time-Resolved Laser-Induced Fluorescence (RTRLIF) includes an excitation laser focused in the excitation fiber, with the fluorescence collection fibers concentrically positioned around the excitation fiber at the optrode tip, which dips into the solution; the signal is analyzed by a pulsed intensified multichannel spectrofluorimeter. This analyzer allows for the elimination of the unwanted parasital fluorescence (organic, Raman) by the placement of a gate a few microseconds after the laser pulse. Special care is taken in terms of laser focalization, fiber-optic parameters (numerical aperture, diameter, and arrangement), parasital fluorescence, time delay, and width of the gate. Results obtained with RTRLIF in terms of limits of detection (LOD ∼ 10−10 M) are presented and compared with the results obtained by TRLIF.

Far field emission of micropillar and planar microcavities lattice-matched to ZnTe

Open Physics ◽  
2011 ◽  
Vol 9 (2) ◽  
Author(s):  
Tomasz Jakubczyk ◽  
Wojciech Pacuski ◽  
Paweł Duch ◽  
Piotr Godlewski ◽  
Andrzej Golnik ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Angular Distribution ◽  
Field Emission ◽  
Field Distribution ◽  
Cross Sections ◽  
Light Emission ◽  
Numerical Aperture ◽  
Far Field ◽  
Lattice Matched ◽  
Isotropic Radiation

AbstractWe investigate light emission from ZnTe-based microcavities containing CdTe quantum dots (QDs), with 2D (planar cavity) and 0D (pillar cavities) photonic confinement. The angular distribution from the planar cavity is presented as well as 2D cross-sections of the far field distribution of radiation from the micropillars. The efficient and desirable modification of the isotropic radiation of the QDs is shown for such structures. The diffraction observed is found to be inherent for such experiments with large numerical aperture of the lens and small diameters of the investigated pillars. This diffraction is successfully modeled.

Analysis of Effective Numerical Aperture in 2-D Photonic Crystal Waveguide

2014 ◽  
Vol 979 ◽  
pp. 455-458
Author(s):  
T. Chantakit ◽  
S. Kamoldilok ◽  
K. Srinuanjan ◽  
P.P. Yupapin
Keyword(s):  
Photonic Crystal ◽  
Fiber Optics ◽  
Numerical Aperture ◽  
Two Dimensional ◽  
Photonic Crystal Waveguide ◽  
Incident Wavelength ◽  
Dimensional Photonic Crystal ◽  
Near Future ◽  
Two Dimensional Photonic Crystal ◽  
Difference Time

The effective numerical aperture calculation in two-dimensional Photonic crystal waveguide has been proposed. In this paper we present the analysis of ray optics refracted inside nanorods and at the boundaries between rods, which separates rod gap is much smaller than the incident wavelength assumed to reflect on the region. In operation, the resolving numerical aperture was compared with the finite difference time domain method via OptiFDTD software. Although numerical aperture mentioned above was found to be extremely close to fiber optics, a transmission passes though compartments of the rods are observed due to significant estimation of transmission and reflection of electric field. The compared simulation results will be discussed. By the aforementioned is that in the near future we will modify wave equation in periodic media of waveguide structures reached to the transverse electric equation of beam propagation in the two-dimensional Photonic crystal waveguide analysed.

scholarly journals Electroluminescent optical fiber sensor for detection of a high intensity electric field

2020 ◽  
Vol 12 (1) ◽  
pp. 19
Author(s):  
Tadeusz Piotr Pustelny
Keyword(s):  
Electric Field ◽  
Optical Fiber ◽  
Fiber Optics ◽  
Fiber Optic ◽  
Light Emission ◽  
Fiber Type ◽  
Optical Fiber Sensor ◽  
Fiber Sensor ◽  
Sensor Technology ◽  
Experimental Investigations

On-line testing of high power electromagnetic devices is one of the most important problems of modern industrial metrology. In the paper, the results of experimental investigations of the electric field optical fiber sensor based on the electroluminescent phenomena are presented. The electro¬luminescent effect is observed in some composite semicon¬ductors, among others in zinc sulfide ZnS crystals. In our investigations, the used ZnS crystal was doped with copper Cu atoms as activators. The concentration of activator in the ZnS crystal was about 5.10-4 [g/g]. According to plans of investi¬gations of the elaborated electroluminescent sensor, the spectral properties as well as the intensity of light emission in sinusoidal alternating electric field were tested.Full Text: PDF References:K.T.V. Grattan, Fiber Optic Fluorescence Thermometry, Chapman and Hall, London, 1996 [CrossRef]K. Kyuma, S. Tai, T. Sawada, "Fiber-optic instrument for temperature measurement", J. Quntum. Electronics, 73(3), 1997 [CrossRef]A. Brief, J. Chem. Educ., 88(6), 731 (2011). [CrossRef]T. Pustelny, B. Pustelny, "Investigation of electroluminophores for their practical application in optical fibre sensor technology", Opto-Electronics Rev.,10(3), 193 (2002). [CrossRef]A.Wrzesinska, Photo- and electroluminophore, Wroclaw, PWN Press, 1988, (in polish) [DirectLink]K.A. Franz, W.G. Kehr, "Luminescent Materials", Ullmans Encyclopedie of Industral Chemistry, Wiley-VCH, Veinhen, 2008 [CrossRef]A.G. Milnes, Deep Impurities In Semiconductors, A Willey-Interscience Publication, Toronto, 1993 [DirectLink]M. Aven, J.S. Prener, Physics and Chemistry of II-VI Compounds, North-Holland Publishing Company - Amsterdam, 1993 [DirectLink]P.K. Cheo, Fiber Optics Devices and Systems, Prentice-Hall, 1985 [CrossRef]D. Randall, Fluorescence and Phosphorescence, Grown, Oxford, 2007. [CrossRef]M. Koen, Photoconductivity of Semiconductors, Edited by Parks, New York, 1996 [CrossRef]K.R. Murphy, C.A. Stedmon, Annal. Methods, 6(3), 658, (2014) [CrossRef]T. Pustelny, K. Barczak, K. Gut, J. Wojcik, "Special optical fiber type D applied in optical sensor of electric currents", Optica Applicata, 34(4), 531 (2004). [DirectLink]K. Barczak, T. Pustelny, D. Dorosz, J. Dorosz, "Polarization maintaining fibers for application in magnetic field measurements", Europ. Phys. Journal: S.T., 154, 11, (2008) [CrossRef]

scholarly journals Comparison of Several Characteristics of Single Mode Step-Index (SMSI), Multimode Step-Index (MMSI), and Multimode Graded-Index (MMGI) Fibers for Optical Communication Systems

2021 ◽  
Vol 9 (12) ◽  
pp. 566-570
Author(s):  
Muhammad Arif Bin Jalil
Keyword(s):  
Fiber Optics ◽  
Optical Communication ◽  
Communication System ◽  
Communication Systems ◽  
Propagation Constant ◽  
Numerical Aperture ◽  
Single Mode ◽  
Optical Communication System ◽  
Step Index ◽  
Graded Index

Abstract: Optical fiber is a medium that made by silica or plastic, and widely used in transmitting information over longer distance especially in communication system. There are three types of fiber optic used in this project which are single mode stepindex (SMSI), multimode step-index (MMSI), and multimode graded-index (MMGI) in optical communication system. There are three objectives in this project in order to get the suitable optical fibers in the communication system. First objective is to simulate the result by using Excel and Origin software. The data and the formula of fiber optics will be key in through Excel software while the graph will be analyzed by using Origin software. The second objective is to compare the different types of fiber optics in communication system by comparing the several of their characteristics such as numerical aperture (NA), acceptance angle (θ(a)) and propagation constant (β). The performance of all types fiber optics are analyzed from the result using the standard communication wavelength of 1550 nm. The core diameter for SMSI, MMSI, and MMGI are 9, 200 and 50 μm respectively while the cladding diameter for SMSI and MMGI is 125 μm and 240 μm for MMSI. This diameter also been analyzed by using the standard value for optical communication system. Then, the comparison between SMSI, MMSI and MMGI will be made to choose the more suitable for optical communication system based on their characteristics. From the results, MMSI and MMGI give best performance compared to SMSI. After that, the third objective is to make the comparison between MMSI and MMGI in term of intermodal dispersion to compare the efficiencies of fiber optics. MMGI give the better result in terms of efficiencies for communication system compared to MMSI. Keyword: Single Mode Step-Index (SMSI), Multimode Step-Index (MMSI), Multimode Graded-Index (MMGI), Communication System, Excel and Origin Software

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