Apparatus for reducing coherence of a laser beam

An apparatus for reducing a coherence of a laser beam, the apparatus comprising:

• a chamber being rectangular, the chamber comprising:
• a first wall, a second wall, and a third wall each comprising a reflective inner surface;
• and
• a fourth wall comprising a beam splitter;
• the fourth wall configured to transmit at least a portion of the laser beam into the chamber to form an input laser beam incident upon the first wall;
• the first wall configured to reflect the input laser beam onto the second wall;
• the second wall configured to reflect the input laser beam onto the third wall;
• and the third wall configured to reflect the input laser beam onto the fourth wall;
• the fourth wall further configured to reflect a first portion of the input laser beam to form a further input laser beam incident upon the first wall and to transmit a second portion of the input laser beam out of the chamber to form an output laser beam;
• the chamber defining a light path extending from the fourth wall, to the first wall, to the second wall, to the third wall, and back onto the fourth wall, the light path being a closed loop, the light path having a length greater than or equal to a coherence length of the laser beam;
• a further chamber being rectangular, the further chamber comprising:
• a further first wall, a further second wall, and a further third wall each comprising a corresponding reflective inner surface;
• and
• a further fourth wall comprising a corresponding beam splitter;
• the further chamber defining a further light path extending from the fourth wall, to the first wall, to the second wall, to the third wall, and back onto the fourth wall, the further light path being a closed loop;
• and
• a middle wall comprising a corresponding reflective surface, the middle wall disposed between the chamber and the further chamber;
• the fourth wall and the further fourth wall facing one another;
• and
• the middle wall parallel with the first wall and the further third wall, the middle wall configured to reflect the output laser beam onto an outer surface of the further fourth wall;
• and
• whereby the further chamber is configured to receive as an input the output laser beam and produce as an output a further output laser beam.