An interferometric measuring device for measuring shapes of rough surfaces of an object to be measured. The measuring device has a radiation generator that emits a short-coherent radiation; a beam splitter for forming a reference beam that is directed toward a device having a reflecting element for periodically changing the light path, and a measuring beam which is directed toward the object to be measured; a superposition element at which the measuring beam coming from the object to be measured...

Method and apparatus are provided for measuring the surface profile of a sample. The method and apparatus provide light from a light source through a beam splitter to form two split beams, direct the split beams onto a sample surface and a reference surface respectively, reflect the split beams back through the beam splitter, and direct the split beams towards an imaging system. A surface profiling apparatus for measuring the surface profile of the sample is also provided. The apparatus includes...

According to an aspect of the present invention, there is provided an inspection apparatus using an optical interferometer including splitting and combining means (3) for splitting light from a light source (1) into incident light (41) irradiated on a sample and reference light (40) and combining signal light which is light scattered or reflected by the sample (7, 42) and the reference light, a modulator (4, 5, 10) for subjecting the reference light to phase modulation and a photo detector (9) f...

In one embodiment, a system to measure defects on a surface of a wafer and an edge of the wafer using a single tool comprises a radial motor to move an optical head in a radial direction to detect defects at locations displaced from the edge of the wafer, and a rotational motor to rotate the optical head around the edge of the wafer to detect defects on the edge of the wafer.

Methods and apparatus for three-dimensional imaging of a sample. A source is provided of a beam of substantially collimated light characterized by a temporally dependent spectrum. The beam is focused in a plane characterized by a fixed displacement along the propagation axis of the beam, and scattered light from the sample is superposed with a reference beam derived from the substantially collimated source onto a focal plane detector array to provide an interference signal. A forward scattering ...

Frequency domain optical coherence imaging systems have an optical source, an optical detector and an optical transmission path between the optical source and the optical detector. The optical transmission path between the optical source and the optical detector reduces an effective linewidth of the imaging system. The optical source may be a broadband source and the optical transmission path may include a periodic optical filter.

Low coherence light is divided into measuring light and reference light. The measuring light is collected to be projected onto an object of measurement. Intensities of the reflected light in a plurality of positions in the direction of depth are detected by carrying out a Fourier analysis on each channeled spectrum obtained by decomposing the detected interference light into frequency components. The optical path length of the reference light is stepwise changed to adjust the optical path length...

A problem occurring in the acquisition of planar sectional images by means of transverse optical coherence tomography consists in that the frequency of the photoelectric interferometer signal is not constant during the scanning process. The corresponding frequency bandwidth impedes the electronic bandpass filtering required for noise reduction. However, planar tomographic images are particularly important. A beam path which is telecentric on the object side is realized in that the center of rota...

An optical coherence tomography (OCT) system including a polarizing splitter disposed to direct light in an interferometer such that the OCT detector operates in a noise-optimized regime. When scanning an eye, the system detector simultaneously produces a low-frequency component representing a scanning laser ophthalmoscope-like (SLO-like) image pixel and a high frequency component representing a two-dimensional (2D) OCT en face image pixel of each point. The SLO-like image is unchanging with dep...

An apparatus and method for obtaining depth-resolved spectra for the purpose of determining the size of scatterers by measuring their elastic scattering properties. Depth resolution is achieved by using a white light source in a Michelson interferometer and dispersing a mixed signal and reference fields. The measured spectrum is Fourier transformed to obtain an axial spatial cross-correlation between the signal and reference fields with near 1 .mu.m depth-resolution. The spectral dependence of s...