Abstract: An irradiation assembly for a laser-based fusion reaction is disclosed. The laser-based fusion reaction is an initiation of a fusion reaction in a fusion fuel pellet by a laser beam. The irradiation assembly comprises: an optical input for the laser beam originating from a laser source; a profile forming component; and at least one steering element. The laser beam has an initial transverse phase distribution and an initial transverse intensity profile. The profile forming component is configured to shape the initial phase distribution of the laser beam so that the initial transverse intensity profile is transformed into a final transverse profile at the fusion fuel pellet. The at least one steering element is configured to steer the laser beam towards the profile forming component or towards the fusion fuel pellet to trigger the fusion reaction in the fusion fuel pellet by the laser beam. The final transverse intensity profile has a Gaussian-like profile when arriving at the fusion fuel pellet.

Abstract: A method for calibrating the angle-axis of signals measuring changes in an index of refraction. A pump beam is generated to propagate near a prism to induce index-changes in air by lining up air molecules outside of the prism. A generated probe beam is directed at the prism. A sinc2 pattern is then generated in a far-field based on a diffraction of a laser beam from a slit, where the laser beam is directed at the prism. An angle-axis of the sinc2 pattern is calibrated using maxima of the sinc2 pattern.