35-dB nonlinear crosstalk suppression in a WDM analog fiber system by complementary modulation of twin carriers

2002 ◽  
Vol 14 (5) ◽  
pp. 699-701 ◽  
Author(s):  
K.K.Y. Wong ◽  
M.E. Marhic ◽  
Min-Chen Ho ◽  
L.G. Kazovsky
Keyword(s):  
Fiber System ◽  
Nonlinear Crosstalk

Modelling Light Transmission in a Fiber-Optical Reflection System

2004 ◽  
Vol 9 (1) ◽  
pp. 55-63
Author(s):  
V. Kleiza
Keyword(s):  
Optical Sensors ◽  
Light Transmission ◽  
External Cavity ◽  
Linear Displacement ◽  
Fiber System ◽  
Light Emitting ◽  
Optical Media ◽  
Reflected Light ◽  
Fiber Optical ◽  
Fiber Optical Sensors

Light transmission in the reflection fiber system, located in external optical media, has been investigated for application as sensors. The system was simulated by different models, including external cavity parameters such as the distance between light emitting and receiving fibers and mirror positioning distance. The sensitivity to a linear displacement of the sensors was studied as a function of the distance between the tips of the light emitting fiber and the center of the pair reflected light collecting fibers, by positioning a mirror. Physical fundamentals and operating principles of the advanced fiber optical sensors were revealed.

The frontal longitudinal system as revealed through the fiber microdissection technique: structural evidence underpinning the direct connectivity of the prefrontal-premotor circuitry

2020 ◽  
Vol 133 (5) ◽  
pp. 1503-1515 ◽  
Author(s):  
Spyridon Komaitis ◽  
Aristotelis V. Kalyvas ◽  
Georgios P. Skandalakis ◽  
Evangelos Drosos ◽  
Evgenia Lani ◽  
...  
Keyword(s):  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Frontal Area ◽  
Frontal Pole ◽  
Fiber System ◽  
Dorsolateral Prefrontal ◽  
Anterior Extension ◽  
Brodmann Areas ◽  
Longitudinal Fiber ◽  
Long Fibers

OBJECTIVEThe purpose of this study was to investigate the morphology, connectivity, and correlative anatomy of the longitudinal group of fibers residing in the frontal area, which resemble the anterior extension of the superior longitudinal fasciculus (SLF) and were previously described as the frontal longitudinal system (FLS).METHODSFifteen normal adult formalin-fixed cerebral hemispheres collected from cadavers were studied using the Klingler microdissection technique. Lateral to medial dissections were performed in a stepwise fashion starting from the frontal area and extending to the temporoparietal regions.RESULTSThe FLS was consistently identified as a fiber pathway residing just under the superficial U-fibers of the middle frontal gyrus or middle frontal sulcus (when present) and extending as far as the frontal pole. The authors were able to record two different configurations: one consisting of two distinct, parallel, longitudinal fiber chains (13% of cases), and the other consisting of a single stem of fibers (87% of cases). The fiber chains’ cortical terminations in the frontal and prefrontal area were also traced. More specifically, the FLS was always recorded to terminate in Brodmann areas 6, 46, 45, and 10 (premotor cortex, dorsolateral prefrontal cortex, pars triangularis, and frontal pole, respectively), whereas terminations in Brodmann areas 4 (primary motor cortex), 47 (pars orbitalis), and 9 were also encountered in some specimens. In relation to the SLF system, the FLS represented its anterior continuation in the majority of the hemispheres, whereas in a few cases it was recorded as a completely distinct tract. Interestingly, the FLS comprised shorter fibers that were recorded to interconnect exclusively frontal areas, thus exhibiting different fiber architecture when compared to the long fibers forming the SLF.CONCLUSIONSThe current study provides consistent, focused, and robust evidence on the morphology, architecture, and correlative anatomy of the FLS. This fiber system participates in the axonal connectivity of the prefrontal-premotor cortices and allegedly subserves cognitive-motor functions. Based in the SLF hypersegmentation concept that has been advocated by previous authors, the FLS should be approached as a distinct frontal segment within the superior longitudinal system.

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