What is the meaning of co-propagating beam?

[cks]

I want to ask, is counter propagating beam written as co-propagating beam?

which means two beams that are traveling opposite to each other.

 

[Andy Resnick]

counter propagating and co-propagating beams generally mean they have the same wavevector: for counterpropagating beams the wavevector has opposite sign, for copropagating, the same sign.

 

[sir-pinski]

The term co-propagating beam refers to two beams of light that are moving in the same direction. This can also be referred to as parallel propagation. In contrast, counter propagating beam refers to two beams of light that are traveling in opposite directions, or antiparallel propagation. So, while co-propagating and counter propagating beams may seem similar, they actually have opposite directions of travel. It is important to use the correct terminology to avoid confusion and accurately describe the direction of light beams. Therefore, co-propagating beam and counter propagating beam are not interchangeable terms.