An apparatus, comprising: a material processing beam source that produces a material processing beam that is applied to a location of a material in a material modification process; an imaging light source that produces imaging light; a coherent imaging system including an optical interferometer that produces an interferometry output using at least a component of the imaging light that is delivered to a phase change region and/or a surrounding region created in the material before, during, and/or after the material modification process, the interferometry output based on at least one optical path length to at least one point in the phase change region and/or the surrounding region compared to another optical path length; a detector that receives the interferometry output and produces a detector output that is indicative of a characteristic of the phase change region and/or the surrounding region during the material modification process, a record generator that generates at least one record based on the detector output at a plurality of times; and one or more auxiliary optical sensor, wherein the one or more auxiliary optical sensor receives at least one optical emission from the phase change region, or the surrounding region, or both, and produces one or more output; wherein the one or more output is connected to at least one of a signal processor, a quality assurance signal generator, a feedback processor, and a record generator; wherein at least one of the signal processor, quality assurance signal generator, feedback processor, and record generator generates at least one of a record, annunciation, and feedback output; characterized in that an optical fiber being one of a multi-clad or multi-core fiber, and wherein the imaging light shares the optical fiber with the one or more auxiliary optical sensor; and the one or more auxiliary optical sensor collects light in a plurality of wavelength bands that measure optical emissions from the process not directly caused by the coherent imaging system. a material processing beam source that produces a material processing beam that is applied to a location of a material in a material modification process; an imaging light source that produces imaging light; a coherent imaging system including an optical interferometer that produces an interferometry output using at least a component of the imaging light that is delivered to a phase change region and/or a surrounding region created in the material before, during, and/or after the material modification process, the interferometry output based on at least one optical path length to at least one point in the phase change region and/or the surrounding region compared to another optical path length; a detector that receives the interferometry output and produces a detector output that is indicative of a characteristic of the phase change region and/or the surrounding region during the material modification process, a record generator that generates at least one record based on the detector output at a plurality of times; and one or more auxiliary optical sensor, wherein the one or more auxiliary optical sensor receives at least one optical emission from the phase change region, or the surrounding region, or both, and produces one or more output; wherein the one or more output is connected to at least one of a signal processor, a quality assurance signal generator, a feedback processor, and a record generator; wherein at least one of the signal processor, quality assurance signal generator, feedback processor, and record generator generates at least one of a record, annunciation, and feedback output; characterized in that an optical fiber being one of a multi-clad or multi-core fiber, and one or more auxiliary optical sensor, wherein the one or more auxiliary optical sensor receives at least one optical emission from the phase change region, or the surrounding region, or both, and produces one or more output; wherein the one or more output is connected to at least one of a signal processor, a quality assurance signal generator, a feedback processor, and a record generator; wherein at least one of the signal processor, quality assurance signal generator, feedback processor, and record generator generates at least one of a record, annunciation, and feedback output; characterized in that an optical fiber being one of a multi-clad or multi-core fiber, and wherein the imaging light shares the optical fiber with the one or more auxiliary optical sensor; and the one or more auxiliary optical sensor collects light in a plurality of wavelength bands that measure optical emissions from the process not directly caused by the coherent imaging system.