Distance Measurement by Means of a Modulated Light Beam yet Independent of the Speed of Light

1967 ◽  
pp. 263-277 ◽  
Author(s):  
K. D. Froome ◽  
R. H. Bradsell
Keyword(s):  
Light Beam ◽  
Distance Measurement ◽  
Speed Of Light ◽  
Modulated Light

Early Ideas

Lightspeed ◽  
2019 ◽  
pp. 4-17
Author(s):  
John C. H. Spence
Keyword(s):  
Light Beam ◽  
Laser Pointer ◽  
Speed Of Light ◽  
Least Action ◽  
Principle Of Least Action ◽  
Modern Physics ◽  
Action At A Distance ◽  
Snell’S Law ◽  
Snell's Law ◽  
The Universe

Mankind’s early ideas about the speed of light, the Aether (supposed to fill the universe) and the instantaneous “action at a distance” theory, before the speed of light was first measured. Euclid’s work on optics, in which he used his theorems from geometry to explain what is seen, assuming that rays of vision were sent out by the eye. The discovery of refraction, explained by Snell’s law and its implications for the speed of light in the theories of Descartes and Fermat, and its importance in modern physics as a principle of least action. How the study of refraction, as when a light beam from a laser pointer bends on entering water, divided scientists for centuries into two groups, those who believed that light sped up on entering water and was a particle, and those who believed it slowed down and was a wave.

scholarly journals Uncertainty in the Phase Flicker Measurement for the Liquid Crystal on Silicon Devices

Photonics ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 307
Author(s):  
Zhiyuan Yang ◽  
Shiyu Wu ◽  
Jiewen Nie ◽  
Haining Yang
Keyword(s):  
Liquid Crystal ◽  
Measurement Uncertainty ◽  
Light Beam ◽  
Performance Parameter ◽  
Phase Response ◽  
Silicon Devices ◽  
Intensity Response ◽  
Liquid Crystal On Silicon ◽  
The Relationship ◽  
Modulated Light

Phase flicker has become an important performance parameter for the liquid crystal on silicon (LCOS) devices. Since the phase response of the LCOS device cannot be measured directly, it is usually derived from the intensity response of the modulated light beam when the LCOS device was placed between a pair of crossed polarisers. However, the relationship between the intensity of the beam and the phase response of the LCOS device is periodic. This would lead to uncertainty in the phase flicker measurement. This paper analyses this measurement uncertainty through both simulation and experiments. It also proposed a strategy to minimise the uncertainty.

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