Design of Novel Beam Demagnifier Based on Total Reflection -Refraction

A novel beam demagnifier(a cone) is presented based on total internal reflection-refraction principle, and the light propagation characteristics inside the cone were studied by using ray-tracing method and computer simulation. This paper presents several proof-theoretic results concerning a cone as a beam demagnifier under certain conditions. When the semiapex angle of the cone is equal to a series of specific values an output beam is parallel to an incident beam, the beam's diameter narrows, and the demagnification ratio of the cone is a function of apex angle and there exists a series of extreme points; the demagnifier can be used in series so as to further narrow or magnify the diameter of incident beam.

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Light propagation mechanism switching in a liquid crystal infiltrated microstructured polymer optical fibre

Opto-Electronics Review ◽

10.1515/oere-2015-0034 ◽

2015 ◽

Vol 23 (4) ◽

Cited By ~ 2

Author(s):

K.A. Rutkowska ◽

K. Milenko ◽

O. Chojnowska ◽

R. Dąbrowski ◽

T.R. Woliński

Keyword(s):

Liquid Crystal ◽

Optical Fibre ◽

Total Internal Reflection ◽

Light Propagation ◽

Propagation Mechanism ◽

External Temperature ◽

Air Channels ◽

Propagation Properties ◽

Infiltration Method ◽

Light Guidance

AbstractIn this work studies on propagation properties of a microstructured polymer optical fibre infiltrated with a nematic liquid crystal are presented. Specifically, the influence of an infiltration method on the LC molecular alignment inside fibre air-channels and, thus, on light guidance is discussed. Switching between propagation mechanisms, namely the transition from modified total internal reflection (mTIR) to the photonic bandgap effect obtained by varying external temperature is also demonstrated.

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Measurement of apex angle of the prism using total internal reflection

Optics & Laser Technology ◽

10.1016/j.optlastec.2004.01.008 ◽

2004 ◽

Vol 36 (8) ◽

pp. 617-624 ◽

Cited By ~ 2

Author(s):

A.M Ghodgaonkar ◽

R.D Tewari

Keyword(s):

Total Internal Reflection ◽

Apex Angle ◽

Internal Reflection

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Characterisation of Biological Materials at THz Frequencies by Attenuated Total Reflection: Lard

Applied Sciences ◽

10.3390/app10238692 ◽

2020 ◽

Vol 10 (23) ◽

pp. 8692

Author(s):

Zoltan Vilagosh ◽

Alireza Lajevardipour ◽

Dominique Appadoo ◽

Soon Hock Ng ◽

Saulius Juodkazis ◽

...

Keyword(s):

Penetration Depth ◽

Evanescent Wave ◽

Total Internal Reflection ◽

Complex Refractive Index ◽

Biological Tissues ◽

Total Reflection ◽

Attenuated Total Reflection ◽

Frustrated Total Internal Reflection ◽

Model Sample ◽

Difference Time

The penetration depth of an evanescent wave in Attenuated Total Reflection (ATR) is dependent on the wavelength of the radiation utilised. At THz frequencies, the penetration depth into biological tissues is in the order of 0.1 to 0.5 mm; rendered pig lard was used as a model sample in this study. A method for the direct measurement of the evanescent wave penetration depth is presented which allows for the estimation of the dispersion of the complex refractive index by using the reflection of the evanescent wave from varying sample depths. The method employs frustrated total internal reflection, and has been demonstrated by using the THz/Far-IR beamline at the Australian synchrotron, and modelled using finite difference time domain (FDTD) simulations.

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