A laser system and interferometer are disclosed comprising a laser source for generating a laser beam, and first and second adjustable elements wherein the first and second adjustable elements have limited rotational motion so rotation of the first adjustable element causes deviation of a laser beam in one plane and rotation of the second adjustable element causes deviation in a second plane, and a laser beam from the laser source is oblique to a required beam direction whereby rotation of the adjustable elements deviates the laser beam enabling alignment of the laser beam to the required beam direction. The adjustable elements may be rotatable through 90.degree.. The first and second planes may be perpendicular to the required beam direction and to each other. At least one mirror may be provided which can be angularly offset to the required beam direction.
