How Does the Gradient Force Arise in Lasers?

[rida]

how come there is an electrical gradient in lasers? i means lasers are just monochromatic photons so how come a particle feels an electrical force there

 

[Drakkith]

A laser emits coherent electromagnetic waves. That's what light is; an electromagnetic wave. This wave consists of electric and magnetic fields that constantly alternate from + to - and back. The higher the intensity of the light, the greater the electric and magnetic forces felt by a particle in the beam path.

Also, depending on the size of the particle and the wavelength, the particle can experience radiation pressure by absorbing or reflecting light, taking some of the lights momentum and being accelerated away from the source.

 

[rida]

in polystyrene bead placed in lase, only the refracted wave is responsible for electrical gradient not the reflected one. how come it is so

 

[Andy Resnick]

how come there is an electrical gradient in lasers? i means lasers are just monochromatic photons so how come a particle feels an electrical force there

Because the intensity varies in spatial extent.

 

[sardar]

The gradient force in lasers is a result of the interaction between the electric field of the laser and the charged particles within the laser medium. This electric field is created by the stimulated emission of photons, which are monochromatic and have a specific frequency. However, the charged particles within the laser medium are not stationary and are constantly moving due to thermal energy. As they move, they interact with the electric field and experience a force known as the gradient force.

This force arises due to the spatial variation in the electric field strength, which can be caused by the geometry of the laser cavity or the presence of other electric fields within the laser medium. The charged particles within the laser medium can be ions, electrons, or even neutral atoms that have been excited to a higher energy state. As they move in response to the electric field, they can also interact with other particles and contribute to the amplification of the laser beam.

In summary, the electrical gradient in lasers is a result of the interaction between the electric field of the laser and the charged particles within the laser medium. This force is essential for the functioning of lasers as it helps to amplify the laser beam and maintain its coherence. Without the gradient force, the laser would not be able to produce a concentrated and powerful beam of light.