US 2003/0169417 A1Published application

Optical configuration and method for differential refractive index measurements

AssigneeReichert, Inc.

InventorsRobert C. Atkinson, Thomas E. Ryan, Keshav Sharma, Michael J. Byrne

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Abstract

An optical configuration for differential refractive index measurements of a test sample relative to a reference sample comprises an optical path along which an illumination beam travels to simultaneously illuminate a pair of optical interfaces on opposite sides of a meridional plane corresponding to the test sample and reference sample, respectively. Partial beams leaving the optical interfaces are redirected by optical means to illuminate different segments of a linear scanned array aligned in the meridional plane. The difference in location of a pair of shadowlines or a pair of resonance minimums formed by the partial beams on the array provides an indication of the refractive index difference.

Claims39

Dependent claims

An optical configuration for use in measuring a difference in refractive index between a test sample and a reference sample, said optical configuration comprising:

an optical path;
a first optical interface associated with said test sample;
a second optical interface associated with said reference sample;
an illumination beam traveling along said optical path, light from said illumination beam being incident upon said first and second optical interfaces to provide a first partial beam defined by the refractive index of said test sample and a second partial beam defined by the refractive index of said reference sample;
a linear scanned array comprising a plurality of photoelectric cells each providing an output pulse during a scan having an amplitude determined by the amount of illumination of the corresponding cell by incident light;
and
optical means for directing said first and second partial beams to illuminate different respective segments of said linear scanned array, said first partial beam exhibiting a feature indicative of said refractive index of said test sample at a first location on said array and said second partial beam exhibiting a feature indicative of said refractive index of said reference sample at a second location on said array;
whereby said difference in refractive index can be determined from a difference between said first and second locations on said array.

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Dependencies are inferred from the claim text.