Laser Autocollimators

An autocollimator is a high-precision, non-contact optical instrument that measures minute angular deviations of optical or mechanical components. It operates by projecting a collimated beam of light (laser light in this case) onto a reflective surface, such as a mirror or flat, and detecting the return image through the same optical axis. Any angular movement of the surface causes a lateral shift in the reflected beam, which can be measured visually by eye or by a position-sensitive detector (e.g., a CMOS or PSD) and converted into angular units. Engineers use autocollimators for tasks like aligning optical systems, checking the flatness or squareness of components, verifying spindle tilt, and performing straightness and parallelism measurements in mechanical assemblies.