An optical beam tracking method comprising: receiving, at signal processing hardware, axis signals (520, 530, 540, 550) from a multi-axis position sensing detector, each axis signal (520, 530, 540, 550) indicative of a beam position of an optical beam incident on the multi-axis position sensing detector, each axis signal (520, 530, 540, 550) corresponding to an axis of the multi-axis position sensing detector; generating, by the signal processing hardware, a reference signal by summing the axis signals (520, 530, 540, 550); for each axis of the multi-axis position sensing detector: converting, by the signal processing hardware, a phase (522, 532, 542, 552) of a first axis signal (520, 540) of the axis to have a 90 degree phase difference from a second axis signal (530, 550) of the axis; generating, by the signal processing hardware, an axis-phasor signal (640, 650) by summing the first and second axis signals (520, 530, 540, 550), the axis-phasor signal (640, 650) having an angle that maps to the beam position of the optical beam; comparing, by the signal processing hardware, the axis-phasor signal (640, 650) and the reference signal to determine a phase difference, the phase difference mapping to a beam position error (780, 790) along the corresponding axis on the multi-axis position sensing detector; and determining, by the signal processing hardware, a mirror position of a mirror directing the optical beam based on the beam position error (780, 790) of each axis of the multi-axis position sensing detector; and actuating, by the signal processing hardware, the mirror to move to the mirror position. receiving, at signal processing hardware, axis signals (520, 530, 540, 550) from a multi-axis position sensing detector, each axis signal (520, 530, 540, 550) indicative of a beam position of an optical beam incident on the multi-axis position sensing detector, each axis signal (520, 530, 540, 550) corresponding to an axis of the multi-axis position sensing detector; generating, by the signal processing hardware, a reference signal by summing the axis signals (520, 530, 540, 550); for each axis of the multi-axis position sensing detector: converting, by the signal processing hardware, a phase (522, 532, 542, 552) of a first axis signal (520, 540) of the axis to have a 90 degree phase difference from a second axis signal (530, 550) of the axis; generating, by the signal processing hardware, an axis-phasor signal (640, 650) by summing the first and second axis signals (520, 530, 540, 550), the axis-phasor signal (640, 650) having an angle that maps to the beam position of the optical beam; comparing, by the signal processing hardware, the axis-phasor signal (640, 650) and the reference signal to determine a phase difference, the phase difference mapping to a beam position error (780, 790) along the corresponding axis on the multi-axis position sensing detector; and converting, by the signal processing hardware, a phase (522, 532, 542, 552) of a first axis signal (520, 540) of the axis to have a 90 degree phase difference from a second axis signal (530, 550) of the axis; generating, by the signal processing hardware, an axis-phasor signal (640, 650) by summing the first and second axis signals (520, 530, 540, 550), the axis-phasor signal (640, 650) having an angle that maps to the beam position of the optical beam; comparing, by the signal processing hardware, the axis-phasor signal (640, 650) and the reference signal to determine a phase difference, the phase difference mapping to a beam position error (780, 790) along the corresponding axis on the multi-axis position sensing detector; and determining, by the signal processing hardware, a mirror position of a mirror directing the optical beam based on the beam position error (780, 790) of each axis of the multi-axis position sensing detector; and actuating, by the signal processing hardware, the mirror to move to the mirror position.