Sensors, ASA(ALT), Phase I
Apparatus & Method to Certify Properties of Infrared Optical Materials
Objective
The objective is development of an apparatus and process for certification of the index of refraction of infrared transmitting optical materials. Surprisingly, the infrared optics industry does not certify the index of their materials on a batch-by-batch basis. This applies to many IR materials, including Germanium, ZnS, ZnSe, GaAs, BaF₂, AMTIR-1, IRG-24, etc. Recent discoveries under the 3GEN FLIR program of record indicated a need to ensure material index of refraction “n” to an accuracy of 0.001 to ensure that specified optical resolution performance is achieved. Current practice involves expensive and time-consuming third-party involvement, rather than the desired inspection at the point of manufacture.
Description
The topic task is to investigate and then demonstrate an apparatus and a process to economically certify the index of refraction of infrared optical materials in the sellable “lens blank” form, which is typically a flat disk or rectangle.
Phase I
The Phase I objective shall be to conceptualize and mathematically substantiate the operating principles of an economic method to certify the temperature and wavelength dependent index of refraction of a flat disk-shaped sample of infrared optical material. Note that the term “certify” does not require absolute value measurements of the material index and could rely on relative comparisons to reference standards.
In any case, the certification accuracy must be to the third decimal place of the index of refraction values over wavelengths from 3.5 – 12.0 microns and temperatures from -40° to +71° C. Note again that absolute measurements across the full temperature and spectral ranges may not be required if other data can provide adequate statistical correlation to reference standards. The method shall be capable of certifying at least the following infrared optical materials: Ge, ZnS, ZnSe, GaAs, BaF₂, AMTIR-1, IRG-26 and IRG-24.
Phase II
The objective of the Phase II effort is to develop a working laboratory apparatus and associated operational procedure which executes the certification process described in the Phase I task. The apparatus shall be evaluated for acquisition and maintenance costs as well as time efficiency during use, with the intention of transitioning the technology for “in-line” use at optical material points of manufacture. Certification data shall be collected and evaluated for proof of performance using samples of at least the following materials: Ge, ZnSe and BaF₂.
Phase III
- Per research, there are three methods [1, 2, 3] that provide novel ways to test IR refractory indices: IR interferometry, IR ellipsometry and IR spectroscopy.
-
- IR interferometry uses interference patters created by splitting an IR beam to measure its optical path.
- IR ellipsometry measures the change in polarization state of an IR light.
- IR spectroscopy analyzes the absorption, emission, or scatter or IR light via an optical material across different wavelengths.
- Of note: The technique, “Near-Infrared Spectroscopy” , combines interferometry and spectroscopy to simultaneously extract optical properties.
- Potential dual use cases for IR refractory testing techniques include:
- Non-destructive testing and inspection including mechanical engineering, like detecting leaks, electronics, and infrastructure testing.
- Quality control and process manufacturing like pharmaceutical, semiconductor, and polymer manufacturing as well as food processing.
- Healthcare uses cases ranging from blood testing to surgery augmentation.
Submission Information
For more information, and to submit your full proposal package, visit the DSIP Portal.
SBIR|STTR Help Desk: usarmy.sbirsttr@army.mil
References:
- Herzberger, M., Salzburg, C., “Refractive Indices of Infrared Optical Materials and Color Correction of Infrared Lenses“, JOSA, Vol. 2, No. 4, April 1962.
- Hilton, A. R., Chalcogenide Glasses for Infrared Optics, McGraw-Hill, © 2010.
- Stefan Krey, Dennis Off, Aiko Ruprecht, “Measuring the refractive index with precision goniometers: a comparative study,” Proc. SPIE 8992, Photonic Instrumentation Engineering, 89920D (8 March 2014); doi: 10.1117/12.2041760
- Hong A. Qiao, Norm C. Anheier, J. David Musgrave, Kathleen Richardson, Daniel W. Hewak, “Measurement of chalcogenide glass optical dispersion using a mid-infrared prism coupler,” Proc. SPIE 8016, Window and Dome Technologies and Materials XII, 80160F (20 May 2011); doi: 10.1117/12.884320
- Andrew Howe, Brianna Ellsworth, Kathleen A. Richardson, and Romain Gaume, “Prism Coupling Refractometry: Enhancing Precision, Accuracy, and Repeatability in the Infrared“, Optifab 2023, edited by Jessica DeGroote Nelson, Blair L. Unger, Proc. of SPIE Vol. 12778, 127780X · © 2023 SPIE
- Christoph Meichner, Andreas E. Schedl, Christian Neuber, Klaus Kreger, Hans-Werner Schmidt, and Lothar Kador, “Refractive-index determination of solids from firstand second-order critical diffraction angles of periodic surface patterns”, AIP Advances 5, 087135, © 2015; https://doi.org/10.1063/1.4928654
- KEYWORDS: Infrared, Optics, Index of Refraction, Certification, Quality, Thermal Imaging, Lens Blank
Objective
The objective is development of an apparatus and process for certification of the index of refraction of infrared transmitting optical materials. Surprisingly, the infrared optics industry does not certify the index of their materials on a batch-by-batch basis. This applies to many IR materials, including Germanium, ZnS, ZnSe, GaAs, BaF₂, AMTIR-1, IRG-24, etc. Recent discoveries under the 3GEN FLIR program of record indicated a need to ensure material index of refraction “n” to an accuracy of 0.001 to ensure that specified optical resolution performance is achieved. Current practice involves expensive and time-consuming third-party involvement, rather than the desired inspection at the point of manufacture.
Description
The topic task is to investigate and then demonstrate an apparatus and a process to economically certify the index of refraction of infrared optical materials in the sellable “lens blank” form, which is typically a flat disk or rectangle.
Phase I
The Phase I objective shall be to conceptualize and mathematically substantiate the operating principles of an economic method to certify the temperature and wavelength dependent index of refraction of a flat disk-shaped sample of infrared optical material. Note that the term “certify” does not require absolute value measurements of the material index and could rely on relative comparisons to reference standards.
In any case, the certification accuracy must be to the third decimal place of the index of refraction values over wavelengths from 3.5 – 12.0 microns and temperatures from -40° to +71° C. Note again that absolute measurements across the full temperature and spectral ranges may not be required if other data can provide adequate statistical correlation to reference standards. The method shall be capable of certifying at least the following infrared optical materials: Ge, ZnS, ZnSe, GaAs, BaF₂, AMTIR-1, IRG-26 and IRG-24.
Phase II
The objective of the Phase II effort is to develop a working laboratory apparatus and associated operational procedure which executes the certification process described in the Phase I task. The apparatus shall be evaluated for acquisition and maintenance costs as well as time efficiency during use, with the intention of transitioning the technology for “in-line” use at optical material points of manufacture. Certification data shall be collected and evaluated for proof of performance using samples of at least the following materials: Ge, ZnSe and BaF₂.
Phase III
- Per research, there are three methods [1, 2, 3] that provide novel ways to test IR refractory indices: IR interferometry, IR ellipsometry and IR spectroscopy.
-
- IR interferometry uses interference patters created by splitting an IR beam to measure its optical path.
- IR ellipsometry measures the change in polarization state of an IR light.
- IR spectroscopy analyzes the absorption, emission, or scatter or IR light via an optical material across different wavelengths.
- Of note: The technique, “Near-Infrared Spectroscopy” , combines interferometry and spectroscopy to simultaneously extract optical properties.
- Potential dual use cases for IR refractory testing techniques include:
- Non-destructive testing and inspection including mechanical engineering, like detecting leaks, electronics, and infrastructure testing.
- Quality control and process manufacturing like pharmaceutical, semiconductor, and polymer manufacturing as well as food processing.
- Healthcare uses cases ranging from blood testing to surgery augmentation.
Submission Information
For more information, and to submit your full proposal package, visit the DSIP Portal.
SBIR|STTR Help Desk: usarmy.sbirsttr@army.mil
References:
- Herzberger, M., Salzburg, C., “Refractive Indices of Infrared Optical Materials and Color Correction of Infrared Lenses“, JOSA, Vol. 2, No. 4, April 1962.
- Hilton, A. R., Chalcogenide Glasses for Infrared Optics, McGraw-Hill, © 2010.
- Stefan Krey, Dennis Off, Aiko Ruprecht, “Measuring the refractive index with precision goniometers: a comparative study,” Proc. SPIE 8992, Photonic Instrumentation Engineering, 89920D (8 March 2014); doi: 10.1117/12.2041760
- Hong A. Qiao, Norm C. Anheier, J. David Musgrave, Kathleen Richardson, Daniel W. Hewak, “Measurement of chalcogenide glass optical dispersion using a mid-infrared prism coupler,” Proc. SPIE 8016, Window and Dome Technologies and Materials XII, 80160F (20 May 2011); doi: 10.1117/12.884320
- Andrew Howe, Brianna Ellsworth, Kathleen A. Richardson, and Romain Gaume, “Prism Coupling Refractometry: Enhancing Precision, Accuracy, and Repeatability in the Infrared“, Optifab 2023, edited by Jessica DeGroote Nelson, Blair L. Unger, Proc. of SPIE Vol. 12778, 127780X · © 2023 SPIE
- Christoph Meichner, Andreas E. Schedl, Christian Neuber, Klaus Kreger, Hans-Werner Schmidt, and Lothar Kador, “Refractive-index determination of solids from firstand second-order critical diffraction angles of periodic surface patterns”, AIP Advances 5, 087135, © 2015; https://doi.org/10.1063/1.4928654
- KEYWORDS: Infrared, Optics, Index of Refraction, Certification, Quality, Thermal Imaging, Lens Blank