In the present invention, a volume holographic optical element is used as
a pump coupler. The holographic coupler allows at least one pump
wavelength to be coupled into the laser medium. The direction of the pump
beam onto the coupler is not co-linear with the direction of the signal
beam out of the coupler. The invention further provides the coupling of
more than one pump wavelengths using a single holographic coupler element
while maintaining the high isolation between pump and signal beam. The
invention further provides a narrow-band reflection grating of various
efficiencies for the signal beam (as part of the laser cavity).