Sealed beam coupler for an isolated environment

A beam coupler assembly for a fiber laser for an isolated environment having an exterior wall defining an interior portion and an exterior portion and an aperture therethrough, said coupler assembly comprising:

• a housing having a sidewall with an interior surface, an exterior surface, a first end and a second end;
• a first seal extending from the interior surface of the housing and dividing the housing into a first section and a second section, the first section and second section being environmentally isolated from one another, said first seal being substantially optically neutral;
• a second seal adjacent to said first seal, the second seal extending from the interior surface of the tubular housing and providing a redundant seal to environmentally isolate the first section from the second section, the second seal being substantially optically neutrat
• an input collimator unit received within the first end of the sidewall of the housing and into the first section and releasably coupled thereto;
• an output collimator unit received within the second end of the sidewall of the housing and into the second section and releasably coupled thereto;
• a flange extending from the exterior surface of the sidewall of the housing and configured and arranged to mount to the aperture on the exterior wall whereby the output collimator unit is within the interior portion of the isolated environment and the input collimator unit is within the exterior portion of the isolated environment, and
• a shroud coupled to said flange and enclosing said output collimator unit, the shroud including a plurality of closable apertures therethrough.