Instruments as specified in the subgroups and characterised by the use of optical measuring means

GPHYSICS G01Measuring instruments G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS MEASURING ANGLES MEASURING AREAS MEASURING IRREGULARITIES OF SURFACES OR CONTOURS

G01B9/00Instruments as specified in the subgroups and characterised by the use of optical measuring means

G01B9/02Interferometers for determining dimensional properties of, or relations between, measurement objects G01B9/02001characterised by manipulating or generating specific radiation properties G01B9/02002Frequency variation G01B9/02003by using beat frequencies generated by mixing of two or more frequencies G01B9/02004by using a continuous frequency sweep or scan G01B9/02005by using discrete frequency stepping or switching G01B9/02007Two or more frequencies or sources used for interferometric measurement G01B9/02008by using a frequency comb G01B9/02009by using two or more low coherence lengths using different or varying spectral width G01B9/0201using temporal phase variation G01B9/02011using temporal polarization variation G01B9/02012using temporal intensity variation G01B9/02014by using pulsed light G01B9/02015characterised by a particular beam path configuration G01B9/02016contacting two or more objects G01B9/02017contacting one object several times G01B9/02018Multiple-pass interferometer G01B9/02019contacting different points on same face of object G01B9/02021contacting different faces of object G01B9/02022contacting one object by grazing incidence G01B9/02023Indirect probing of object G01B9/02024Measuring in transmission G01B9/02025Interference between three or more discrete surfaces G01B9/02027Two or more interferometric channels or interferometers G01B9/02028Two or more reference or object arms in one interferometer G01B9/02029Combination with non-interferometric systems G01B9/0203With imaging systems G01B9/02031With non-optical systems G01B9/02032generating a spatial carrier frequency G01B9/02034characterised by particularly shaped beams or wavefronts G01B9/02035Shaping the focal point G01B9/02036by using chromatic effects G01B9/02037by generating a transverse line focus G01B9/02038Shaping the wavefront G01B9/02039by matching the wavefront with a particular object surface shape G01B9/02041characterised by particular imaging or detection techniques G01B9/02042Confocal imaging G01B9/02043Imaging of the Fourier or pupil or back focal plane G01B9/02044Imaging in the frequency domain G01B9/02045using the Doppler effect G01B9/02047using digital holographic imaging G01B9/02048Rough and fine measurement G01B9/02049characterised by particular mechanical design details G01B9/0205of probe head G01B9/02051Integrated design G01B9/02052Protecting G01B9/02054Hand held G01B9/02055characterised by error reduction techniques G01B9/02056Passive error reduction, i.e. not varying during measurement G01B9/02057by using common path configuration G01B9/02058by particular optical compensation or alignment elements G01B9/02059Reducing effect of parasitic reflections G01B9/02061Reducing or preventing effect of tilt or misalignment G01B9/02062Active error reduction G01B9/02063by particular alignment of focus position G01B9/02064by particular adjustment of coherence gate G01B9/02065using a second interferometer before or after measuring interferometer G01B9/02067by electronic control systems G01B9/02068Auto-alignment of optical elements G01B9/02069Synchronization of light source or manipulator and detector G01B9/0207Error reduction by correction of the measurement signal based on independently determined error sources G01B9/02071by measuring path difference independently from interferometer G01B9/02072by calibration or testing of interferometer G01B9/02074of the detector G01B9/02075of particular errors G01B9/02076Caused by motion G01B9/02077of the object G01B9/02078Caused by ambiguity G01B9/02079Quadrature detection G01B9/02081simultaneous quadrature detection G01B9/02082Caused by speckles G01B9/02083characterised by particular signal processing and presentation G01B9/02084Processing in the Fourier or frequency domain when not imaged in the frequency domain G01B9/02085Combining two or more images of different regions G01B9/02087Combining two or more images of the same region G01B9/02088Matching signals with a database G01B9/02089Displaying the signal G01B9/0209Non-tomographic low coherence interferometers G01B9/02091Tomographic low coherence interferometers G01B9/02092Self-mixing interferometers G01B9/02094Speckle interferometers G01B9/02095detecting deformation from original shape G01B9/02096detecting a contour or curvature G01B9/02097Self-interferometers G01B9/02098shearing interferometers G01B9/021using holographic techniques G01B9/023for contour producing G01B9/025Double exposure technique G01B9/027in real time G01B9/029by time averaging G01B9/04Measuring microscopes G01B9/06Measuring telescopes G01B9/08Optical projection comparators G01B9/10Goniometers for measuring angles between surfaces