Understanding Optical Coupling: A Key Concept in Modern Optics

[Psi-String]

What is "optical coupling" ??

This may problem may sound stupied,
but what is "optical coupling" ??

I did surf the net to find some information, but I can't find the definition of optical coupling, and I can't even find it in "Encyclopedia of Modern Optics".

Could someone please tell me what is optical coupling all about??

P.S I encounter the problem because of physics experiment class. The phenomina is associated with complete internal reflection.

 

[marcusl]

The totally internally reflected wave produces what's called an evanescent wave on the other side of the boundary. Essentially a little of the wave "leaks out", extending a very small distance out of the medium (e.g. glass) into the air. This is not a propagating wave, however, and no power is carried away. If you bring a second identical medium that also supports total internal reflection, and you position it so close that the two regions of evanescent waves overlap, then power couples from one into the other. This may be what you are referring to as "optical coupling."

Try repeating your search on evanescent coupling or evanescent wave coupling.

 

[Psi-String]

Thanks marcusl ! You lead me to many available source.
Also thanks for your brief and clear explanation!

 

[marcusl]

Happy to help!

 

[J77]

Could also be when you have two separate light sources, eg. lasers, which couple (lase) into one another.

 

[Psi-String]

J77, could you explain more details about your example to me??

Is this kind of couple relates to interference

Thanks for help!

 

[J77]

J77, could you explain more details about your example to me??

From my point of view, coupled lasers correspond to the case when one laser injects its light into another and vice versa.

This coupling can lead to continuous wave type solutions in both lasers which may be in phase or out of phase. It can also lead to more exotic dynamics -- such as relaxation oscillations, oscillations which depend on the detuning between the two laser's free-running frequencies, through to more complex quasiperiodic modulations through to chaotic dynamics.

Lasers may be injected into one another directly, or through an optical fibre.

Just my take on it tho

 

[Psi-String]

I see. Thanks a lot!