Polarization based optical sensor utilizing total internal reflection

Claim 1

A polarization based optical sensor utilizing total internal reflection for detecting substances and changes in said substances on a transparent material comprising at least one polarized-light source that generates a polarized light, at least one polarized-light detector that is sensitive to a particular polarization of light, and said transparent material that is transparent to said polarized light; said polarized-light source oriented so that said polarized light produced thereby enters said transparent material, undergoes a number of substantially-total-internal reflections within said transparent material by striking a boundary of said transparent material at an angle of incidence greater than both a critical angle for a surrounding medium and a critical angle for said substances, exits said transparent material, and strikes said polarized-light detector; said polarized-light source also oriented so that said polarized light produced thereby has an original-electric field consisting of a parallel-electric field parallel to a plane of incidence of said substantially-total-internal reflections and a perpendicular-electric field perpendicular to said plane of incidence of said substantially-total-internal reflections; said polarized light having a phase shift between said parallel-electric field and said perpendicular-electric field; said phase shift dependent upon an index of refraction of said substances and said surrounding medium at said substantially-total-internal reflections, a change in said substances causing a corresponding change in said index of refraction, in turn causing a resulting change in said phase shift; said resulting change in said phase shift causing a transfer of energy between said original-electric field and an electric field perpendicular to said original-electric field; said polarized-light detector oriented so that said transfer of energy causes a measurable change in an output of said polarized-light detector; whereby said substances and changes in said substances are detected.

Claim 9

A method for detecting substances and changes in said substances on a transparent material using at least one polarized-light source and at least one polarized-light detector comprising the steps of: shining a polarized light from said polarized-light source into said transparent material such that said polarized light undergoes a number of substantially-total-internal reflections within said transparent material by striking a boundary of said transparent material at an angle of incidence greater than both a critical angle for a surrounding medium and a critical angle for said substances; propagating said polarized light through said transparent material with an original-electric field consisting of a parallel-electric field parallel to a plane of incidence of said substantially-total-internal reflections and a perpendicular-electric field perpendicular to said plane of incidence of said substantially-total-internal reflections; changing a phase shift between said parallel-electric field and said perpendicular-electric field by changing said substances and thus changing an index of refraction of said substances at said substantially-total-internal reflections, a change in said phase shift causing a transfer of energy between said original-electric field and an electric field perpendicular to said original-electric field; and detecting said transfer of energy with said polarized-light detector after said polarized light exits said transparent material.

Claim 10

A method for detecting substances and changes in said substances on a transparent material using at least one polarized-light source and at least one polarized-light detector comprising the steps of: shining a polarized light from said polarized-light source into said transparent material such that said polarized light undergoes a number of substantially-total-internal reflections within said transparent material by striking a boundary of said transparent material at an angle of incidence greater than both a critical angle for a surrounding medium and a critical angle for said substances; propagating said polarized light through said transparent material with an original-electric field consisting of a parallel-electric field parallel to a plane of incidence of said substantially-total-internal reflections and a perpendicular-electric field perpendicular to said plane of incidence of said substantially-total-internal reflections; changing a phase shift between said parallel-electric field and said perpendicular-electric field by changing said substances and thus changing an index of refraction of said substances at said substantially-total-internal reflections, a change in said phase shift causing a transfer of energy between said original-electric field and an electric field perpendicular to said original-electric field; and detecting said transfer of energy with said polarized-light detector after said polarized light exits said transparent material.