An additive manufacturing device (100, 200, 300, 600) for fabricating an article, comprising: a stage configured to support a substrate; a printhead disposed above the stage, the printhead configured to heat a build material to a molten build material and deposit the molten build material on the substrate in the form of droplets to fabricate the article; a targeted heating system disposed proximal the printhead, the targeted heating system configured to control a temperature or temperature gradient of the droplets deposited on the substrate, an area proximal the substrate, or combinations thereof, wherein the targeted heating system comprises a laser system (400, 500), the laser system (400, 500) characterised therein by comprising: a fiber coupled laser module; an output fiber coupled with the fiber coupled laser module; a collimator disposed downstream of the fiber output; a polarization rotator disposed downstream of the collimator; a variable retarder disposed downstream of the collimator; and a wave retarder disposed downstream of the variable retarder; a first polarizer, a second polarizer, and a third polarizer, wherein: the first polarizer is disposed between the collimator and the polarization rotator, the second polarizer is disposed between the polarization rotator and the variable retarder, and the third polarizer is disposed downstream of the wave retarder, optionally wherein the polarization rotator is disposed upstream of the variable retarder and the wave retarder, or the first polarizer is disposed between the collimator and the variable retarder, the second polarizer is disposed between the wave retarder and the polarization rotator, and the third polarizer is disposed downstream of the polarization rotator, optionally wherein the variable retarder and the wave retarder are disposed upstream of the polarization rotator. a stage configured to support a substrate; a printhead disposed above the stage, the printhead configured to heat a build material to a molten build material and deposit the molten build material on the substrate in the form of droplets to fabricate the article; a targeted heating system disposed proximal the printhead, the targeted heating system configured to control a temperature or temperature gradient of the droplets deposited on the substrate, an area proximal the substrate, or combinations thereof, wherein the targeted heating system comprises a laser system (400, 500), the laser system (400, 500) characterised therein by comprising: a fiber coupled laser module; an output fiber coupled with the fiber coupled laser module; a collimator disposed downstream of the fiber output; a polarization rotator disposed downstream of the collimator; a variable retarder disposed downstream of the collimator; and a wave retarder disposed downstream of the variable retarder; a fiber coupled laser module; an output fiber coupled with the fiber coupled laser module; a collimator disposed downstream of the fiber output; a polarization rotator disposed downstream of the collimator; a variable retarder disposed downstream of the collimator; and a wave retarder disposed downstream of the variable retarder; a first polarizer, a second polarizer, and a third polarizer, wherein: the first polarizer is disposed between the collimator and the polarization rotator, the second polarizer is disposed between the polarization rotator and the variable retarder, and the third polarizer is disposed downstream of the wave retarder, optionally wherein the polarization rotator is disposed upstream of the variable retarder and the wave retarder, or the first polarizer is disposed between the collimator and the variable retarder, the second polarizer is disposed between the wave retarder and the polarization rotator, and the third polarizer is disposed downstream of the polarization rotator, optionally wherein the variable retarder and the wave retarder are disposed upstream of the polarization rotator. the first polarizer is disposed between the collimator and the polarization rotator, the second polarizer is disposed between the polarization rotator and the variable retarder, and the third polarizer is disposed downstream of the wave retarder, optionally wherein the polarization rotator is disposed upstream of the variable retarder and the wave retarder, or the first polarizer is disposed between the collimator and the variable retarder, the second polarizer is disposed between the wave retarder and the polarization rotator, and the third polarizer is disposed downstream of the polarization rotator, optionally wherein the variable retarder and the wave retarder are disposed upstream of the polarization rotator.