High power laser assembly with accurate pointing in the far field

A laser assembly for generating a mid-infrared output beam directed along an output axis, the laser assembly comprising:

• a first laser that generates a first laser beam in a mid-infrared range having a first polarization state;
• a first lens assembly that collimates the first laser beam;
• a second laser that generates a second laser beam in the mid-infrared range;
• a second lens assembly that collimates the second laser beam;
• a polarization beam combiner that combines the collimated first laser beam and the collimated second laser beam to form a combination beam;
• and
• an optical assembly that receives the combination beam and provides the mid-infrared output beam, the optical assembly including a first lens, a second lens, and a third lens that are spaced apart from each other;
• wherein the first lens is a convex element that focuses the combination beam, the second lens is a diverging element that diverges the combination beam, and the third lens is a collimating element that collimates the combination beam to launch the output beam into free space;
• wherein the lenses of the optical assembly are coaxial with, and spaced apart along, the output axis;
• wherein the first lens, the second lens and the third lens cooperate to minimize pointing errors of the output beam so that the output beam is accurately pointed in a far field.

A method generating an output beam comprising:

• generating a first laser beam;
• collimating the first laser beam;
• generating a second laser beam;
• collimating the second laser beam;
• combining the collimated first laser beam and the collimated second laser beam to form a combination beam;
• and
• expanding and collimating the combination beam with an optical assembly to provide the output beam that is accurately pointed in a far field, and pointing of the output beam is relatively insensitive to temperature cycles and mechanical vibrations.