Four fixture types are intended for alignment of multi-fiber connectors and ferrules in interferometric microscopes for measuring connector end-face geometry. A methodology of fixtures' calibration ensures validity and accuracy of measurements. First fixture type is equipped with a locking mechanism. In one embodiment it contains two guide holes and is intended for male connectors. In another embodiment intended for female connectors and ferrules it contains two removable guide pins on a bar inserted into the guide holes from back or front side of the fixture. Second fixture type has single window in the base and a pair of guide pins located near opposite sides of the window. Third fixture type has a single window and single guide pin in the base located near one window side. Fourth fixture type has a single guide pin in the center of the base and a pair of windows on both sides of the pin.