Adjusting and Determining the Direction of the Axis of a Telescopic Resonator

Abstract—A method for adjusting an unstable confocal resonator and determining its axis direction using an angular reflector is proposed. A semiconductor laser was used as an auxiliary laser, which set the direction of the cavity axis. A collimator was used as the device that controls tuning. A corner reflector mounted inside the resonator from the side of the concave mirror made it possible to create the “direct” and “reverse” passages of the beam of the collimator through the resonator. This makes it possible to observe images of the collimator scale in the eyepiece from the “direct” and “return” passages. Fine tuning of the resonator is carried out by combining the centers of the scales, while the axis of the resonator coincides with the axis of the collimator.