Patent ID: 10642075

Abstract:
A phase controller for rapid, accurate, stable phase shifting of a continuous wave (cw) laser output combines and adjusts reference paths from before and after an EOPM to obtain maximum constructive interference when the EOPM control voltage is zero. A control voltage V for maximum destructive interference is then determined and regulated to produce and maintain a 180 degree phase shift. The output phase can then be shifted by switching the control voltage to the output of a voltage shifter that shifts V by a specified percentage. The phase shifter can divide the control voltage in half to provide a 90 degree phase shift. The cw laser can function as a seed to a pulsed laser, thereby controlling the pulse phases. Quadrature phase laser pulse pairs can be used for quadrature LiDAR detection. Embodiments include a plurality of voltage shifters for 4-phase quadrature shifting and/or shifting between arbitrary phase values.