Patent ID: 7006283

Claim:
An optical amplifier stage for amplifying a light beam comprising: a first lens having a collimating end, a focusing end, an optical axis, and a focal point lying on the optical axis, the first lens for receiving the light beam at the collimating end for directing the light beam towards the focal point along a first path s 1 ; an amplifying medium disposed along the optical axis for amplifying the light beam propagating along the first path s 1 ; a reflector disposed for reflecting the light beam back through the amplifier medium towards the focusing end of the first lens along a second path s 2 to amplify the light beam, wherein the first path s 1 and the second path s 2 lie in a same plane P 1; and N redirecting means {R 1 , R 2 , R 3 , . . . , R N }, N being a natural number, disposed adjacent the collimating end of the lens; wherein redirecting means R x , x being a natural number between 1 and N, receives the light beam propagating along the path s 2x , and redirects the light beam through the first lens back through the amplifier medium along a path s 2x+1 to amplify the light beam; wherein, s 2x+1 and s 2(x+1) lie in a same plane P x+1 ; and wherein all the planes are distinct.