For laser detonator application, high-peak power pulsed Nd:YAG laser is transmitted through all-silica optical fiber. The
transmission properties of step-index fibers are investigated, using a high-peak power pulsed Nd: YAG rod laser with
beyond 1MW power and Q-switch mode. The fibers are step-index multimode fibers with 400 or 600 μm core diameters,
440 or 660 μm cladding diameters. The power delivery characteristics were studied by theory and experiments. The
results show that the fiber core diameter, NA, length and so on affect the transmission efficiency for high power laser.
When the laser power is beyond a certain threshold, the SRS and SBS will be serious; the quantity of fiber end-face
limits to the raising of laser power passing through fibers; the zero-probability damage threshold is calculated according
to ISO/DIS standard 11254-1.2, which is 58.6J/cm2. Energy distribution of output beam from fibers will be uniform.
Even the fiber end-face was partly damaged, laser power is still deliverable, and the transmission efficiency is related to
the fiber damage grade.