ABSORBING SUBSTRATE MIRROR

Provided for herein is a mirror including a substrate and a reflective coating, wherein the substrate is absorptive at a first wavelength and transmissive at a second wavelength, wherein the reflective coating is reflective at the first wavelength; and wherein the reflective coating is arranged on a first side of the substrate opposite a second side of the substrate; a first radiation source configured to transmit radiation at the first wavelength incident on the first side of the substrate; and a second radiation source configured to transmit radiation at the second wavelength incident on the second side of the substrate.