Patent ID: 8798105

Claim:
A laser target designator, comprising: a gain element having a primary axis terminated by a front end and a back end; a pumping source cooperative with the gain element and configured to transmit optical pumping energy into the gain element through its back end; a first Porro prism positioned to intercept light emerging at a first angle from the front end of the gain element and oriented to reflect the light back into the front end of the gain element; a second Porro prism positioned to intercept light emerging at a second angle from the front end of the gain element and oriented to reflect the light back into the front end of the gain element, the second Porro prism having a crossed orientation relative to the first Porro prism, the gain element and the first and second Porro prisms forming an optical resonator path in which light reflected by the first Porro prism travels through a first Porro leg, enters the front end of the gain element at the first angle, undergoes total internal reflection within the gain element and is amplified thereby, emerges from the front end of the gain element at the second angle, travels through a second Porro leg, and strikes the second Porro prism, the light being thereby reflected so that it substantially reverses its path and returns through the gain element to the first Porro prism; and a beam extraction mechanism intersecting the resonator path and configured to extract a portion of the light in the resonator path to form an output beam, the beam extraction mechanism being configured to direct the output beam toward the front end of the gain element so that the output beam passes twice through the gain element without internal reflection, thereby amplifying the output beam before it emerges from the designator.