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This serves the purpose of gravely enhancing the power of the light, and the radiation pressure it can exert on objects and materials. Optical control (that is, manipulation of the motion) of a plethora of objects has been realized: from kilometers long beams (such as in the LIGO interferometer ) [ 28 ] to clouds of atoms, [ 29 ] and from micro ...
Intensity is used most frequently with waves such as acoustic waves , matter waves such as electrons in electron microscopes, and electromagnetic waves such as light or radio waves, in which case the average power transfer over one period of the wave is used. Intensity can be applied to other circumstances where energy is transferred.
The simplest way to obtain the power transmission coefficient (transmissivity, the ratio of transmitted power to incident power in the direction normal to the interface, i.e. the y direction) is to use R + T = 1 (conservation of energy). In this way we find
Multiplication by 1/2 is required to properly describe the power flow since the magnitudes of E m and H m refer to the peak fields of the oscillating quantities. If rather the fields are described in terms of their root mean square (RMS) values (which are each smaller by the factor 2 / 2 {\displaystyle {\sqrt {2}}/2} ), then the correct average ...
Optical power meters usually display time-averaged power. So for pulse measurements, the signal duty cycle must be known to calculate the peak power value. However, the instantaneous peak power must be less than the maximum meter reading, or the detector may saturate, resulting in wrong average readings.
Pressure inside an incandescent light bulb [52] 75 kPa Minimum airplane cabin pressure and lowest pressure for normal breathing (at 2440 m) and also the limit stated by the Federal Aviation Regulation (FAR) [53] 80 kPa 12 psi Pressure inside vacuum cleaner at sea level on Earth (80% of standard atmospheric pressure) [citation needed] 87 kPa 13 psi
Emission spectrum of a fluorescent light, exhibiting many spectral lines. Each line corresponds to an energy level in one of the elements inside the light. A spectral line can result from an electron transition in an atom, molecule or ion, which is associated with a specific amount of energy, E. When this energy is measured by means of some ...
• is the time-average; S is the Poynting vector; α is the angle between a unit vector normal to the surface and S. For a propagating sinusoidal linearly polarized electromagnetic plane wave, the Poynting vector always points to the direction of propagation while oscillating in magnitude. The irradiance of a surface is then given by [3]