A system for generating laser sustained broadband light includes a pump source configured to generate a pumping beam, a gas containment structure for containing a gas and a multi-pass optical assembly. The multi-pass optical assembly includes one or more optical elements configured to perform a plurality of passes of the pumping beam through a portion of the gas to sustain a broadband-light-emitting plasma. The one or more optical elements are arranged to collect an unabsorbed portion of the pumping beam transmitted through the plasma and direct the collected unabsorbed portion of the pumping beam back into the portion of the gas.