Patent ID: 7031352

Claim:
A laser cavity for generating a pulsed laser output, comprising: a gain medium including a light transmission axis; at least one optical element disposed on one side of the gain medium to return laser light emitted from the one side of the gain medium back through the gain medium; a polarization selective element disposed on the light transmission axis to the other side of the gain medium; at least one further optical element arranged to define a cyclic optical path from the polarization selective element along which laser light is in use directed in one of the two directions depending on the polarization of the laser light; and at least one electro-optical element disposed in the optical path and being operable to switch the polarity of the laser light transmitted therethrough such as to generate a pulsed laser output; wherein the at least one further optical element comprises first and second further optical elements, with the first further optical element reflecting laser light to or from the second optical surface of the polarizer and the second further optical element reflecting laser light to or from the first optical surface of the polarizer; and wherein the at least one electro-optical element is disposed between the first and second further optical elements.