1. Where can i go for adjustable fiber optic cable i.e. L-shape cable. MY HT cabinet not deep enuff for my AVR cables..

thanks.

i believe fiber optic required around 10cm diameter for bending angle. 90degree angle will break the light/laser beam.

You should have at least 50cm depth for your cabinet... looks like you need to put the AVR "on" the cabinet?

Try coaxial instead? Provided you source has coaxial outputs.

Of course Coaxial cables are stiff with the shielding, use it with a L shaped RCA connector...you can try the car accessories shop.

You using fibec optic to connect with what device?