How can i use the optical cable for TV to make sound from home theater?

[some14mine]

I bought an optical cable to connect my TV to the home theater and transfer the sound to this. i set the home theater on AUX 1 and AUX 2 but the sound didn't play from home theater. id don't know what should i do to remove this problem.

 

[BrandonYoung]

Is there an option in the TV to change the audio output? I have to do this on my Sony Bravia.