An optical apparatus includes a coherent light source; a transmission assembly configured to receive light emitted by the coherent light source, split the light into object light and reference light so that the object light and the reference light travel along different paths receive object light reflected by an object to be measured, and combine the object light reflected by the object to be measured and the reference light; and a photosensitive camera disposed at an output of the transmission assembly, and configured to receive combined light and process the combined light to record light intensity information capable of characterizing a spatial position of a surface of the object to be measured.