Single Mode cable is a single stand (most applications use 2 fibers) of glass fiber with a diameter of 8.3 to 10 microns that has one mode of transmission. Single Mode Fiber with a relatively narrow diameter, through which only one mode will propagate typically 1310 or 1550nm. Carries higher bandwidth than multimode fiber, but requires a light source with a narrow spectral width. Synonyms mono-mode optical fiber, single-mode fiber, single-mode optical waveguide, uni-mode fiber.

Every single mode can act as a multi mode fiber for light having shorter wavelengths than the one it is designed to be single mode for.

Yes, it can. But it requires a special converter - single to multi-mode.

mode means path, the way in which light travel, in the fiber means angle in multi mode fiber light can travel in more then one angle so it is called multi mode fiber.

but in single mode fiber there is dedicated path or single path through which light beam/source can travel.

Hi,

Single mode fiber is used to send the data from transmitter to receiver or repeater. In single mode we can only send single signal at a time and hence it is single mode.

The Single mode fiber will have core and cladding arranged in such a way that the core has got one refractive index and the cladding has got another refractive index which will be constant through out the fiber.