Method and device for measuring the optical properties of at least two regions located at a distance from one another in a transparent and/or diffuse object

Device for measuring in a measuring time of sub-second range optical properties of at least two mutually spaced regions at a transparent and/or diffusive object, said device comprising:

• a detector-unit,
• an optical arrangement having a Michelson interferometer, said interferometer having a measuring and a reference arm,
• said interferometer having a radiation source generating a radiation being emitted into said measuring and reference arm,
• into said measuring arm said optical object being introduced,
• said object having at least one reflecting region,
• said reference arm having a path length variation unit for said radiation in said reference arm and a reflector for reflecting said radiation, with the aid of said path-length-variation unit a periodic change in path length for the radiation in said reference arm being generated and reflected to said detector-unit, said measuring arm having a detour unit said detour-unit being arranged upstream of said object,
• said detour-unit creating at least one first and at least one second measuring beam,
• said detour-unit imparting said first measuring beam with a detour against said second measuring beam,
• said detour creating a longer optical way to said first measuring beam in relation to said second measuring beam, and
• except for a determination tolerance, said detour being selected is equal to the distance between said spaced regions to be measured,
• said radiation-source generating a radiation having a coherence-length that is shorter than the distance between said two regions to be measured;
• said detector-unit detecting an interfering fashion of said reflected radiation of said reference arm with reflected radiation of said first and second measuring beam radiation in relation to an actual path-length of said reference arm.

Use of device for measuring in a measuring time of a sub-second range a thickness and/or distance of optical regions, present in a transparent and/or diffusive object, of different optical properties including reflective index transitions, said device comprising:

• a detector-unit,
• an optical arrangement having a Michelson-Interferometer,
• said interferometer having a measuring and a reference arm,
• said interferometer having a radiation-source generating a radiation being emitted into said measuring and reference arm
• into said measuring arm said transparent and/or diffusive object being introduced,
• said object having at least one reflecting region,
• said reference arm having a path-length-variation-unit for said radiation in said reference arm and a reflector for reflecting said radiation as a third beam,
• with the aid of said path-length variation-unit a periodic change in path-length for said radiation in said reference arm being generated and reflected to said detector-unit,
• said measuring arm having a detour-unit,
• said detour-unit being arranged upstream of said object,
• said detour-unit creating at least one first and at least one second measuring beam,
• said detour-unit imparting said first measuring beam with a detour against said second measuring beam,
• said detour creating a longer optical way to said first measuring beam in relation to said second measuring beam, and
• except for a determination tolerance, said detour being selected is equal to the distance between said spaced regions in said transparent and/or diffusive object to be measured,
• said radiation-source generating a radiation having a coherence-length that is shorter than the distance between said two regions to be measured;
• said detector-unit detecting an interfering fashion of said third beam with reflected radiation of said first and second measuring beam radiation in relation to an actual path-length of said reference arm,
• the thickness and/or the distance of the optical regions is determined by the interference fashion in relation to the length-value of the path-length-variation of the third beam and the detour-length-value of the detour-unit.

Use of a device for measuring in a measuring time of a sub-second range a thickness and/or a distance of optical regions, present in a transparent and/or diffusive object of different optical properties, such as, for example reflective index transitions, where said object is difficult to be fixed in a timely stable position,

• said device comprising:
• a detector-unit,
• an optical arrangement having a Michelson-Interferometer, said interferometer having a measuring and a reference arm, said interferometer having a radiation source generating a radiation being emitted into said measuring and reference arm into said measuring arm said transparent and/or diffusive object being introduced,
• said object having at least one reflecting region, said reference arm having a path-length-variation-unit for said radiation in said reference arm and a reflector for reflecting said radiation as a third beam, with the aid of said path-length-variation-unit a periodic change in path-length for said radiation in said reference arm being generated and reflected to said detector-unit, said measuring arm having a detour-unit,
• said detour-unit being arranged upstream of said object, said detour-unit creating at least one first and at least one second measuring beam,
• said detour-unit imparting said first measuring beam with a detour against said second measuring beam, said detour creating a longer optical way to said first measuring beam in relation to said second measuring beam, and except for a determination tolerance, said detour being selected is equal to the distance between said spaced regions in said transparent and/or diffusive object to be measured,
• said radiation-source generating a radiation having a coherence-length that is shorter than the distance between said two regions to be measured;
• said detector-unit detecting an interfering fashion of said third beam with reflected radiation of said first and second measuring beam radiation in relation to an actual path-length of said reference arm, the thickness and/or the distance of the optical regions is determined by the interference fashion in relation to the length value of the path-length-variation of the third beam and the detour-length value of the detour-unit.

Use of a device for measuring in a measuring time of a sub-second range a profile of an object, which reflects radiation and is difficult to be fixed in a timely stable position,

• said device comprising:
• a detector-unit, an optical arrangement having a Michelson-Interferometer,
• said interferometer having a measuring and a reference arm,
• said interferometer having a radiation-source generating a radiation being emitted into said measuring and reference arm into said measuring arm said object being introduced, said object having at least one reflecting region, said reference arm having a path-length-variation-unit for said radiation in said reference arm and a reflector for reflecting said radiation as a third beam, with the aid of said path-length-variation-unit a periodic change in path-length for said radiation in said reference arm being generated and reflected to said detector-unit, said measuring arm having a detour-unit, said detour-unit being arranged upstream of said object,
• said detour-unit creating at least one first and at least one second measuring beam, said detour-unit imparting said first measuring beam with a detour against said second measuring beam, said detour creating a longer optical way to said first measuring beam in relation to said second measuring beam, and except for a determination tolerance, said detour being selected is equal to the difference of the profile level values between lateral level points on said object to be profiled, said radiation-source generating a radiation having a coherence-length that is shorter than the distance between said two regions to be measured;
• said detector-unit detecting an interfering fashion of said third beam with reflected radiation of said first and second measuring beam radiation in relation to an actual path-length of said reference arm, the profile of the object being determined by the interference fashion in relation to the length-value of the path-length-variation of the third beam and the detour-length-value of the detour-unit and the values of the lateral level points.