Infrared Optical Properties of Materials

1 Page 1 NIST Special Publication 250-94 Infrared Optical Properties of Materials Leonard Hanssen Simon Kaplan Raju Datla This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.SP.250-94 Open at page → 2 Page 2 NIST Special Publication 250-94 Infrared Optical Properties of Materials Leonard Hanssen Simon Kaplan Raju Datla Sensor Science Division Physical Measurement Laboratory This publication is available free of charge from:... Open at page → 3 Page 3 Certain commercial entities, equipment, or materials may be identified in this document in order to describe an experimental procedure or concept adequately. Such identification is not intended to imply recommendation or... Open at page → 4 Page 4 Abstract This document describes the Fourier Transform Infrared Spectrophotometry (FTIS) Facility at the Sensor Science Division (SSD) of the National Institute of Standards and Technology (NIST), which provides the infr... Open at page → 5 Page 5 Table of Contents Abstract ....................................................................................................................................................... iii 1.Introduction ......................... Open at page → 6 Page 6 4.0. Measurement Assurance ..................................................................................................................... 69 4.1. Sources of Error studies ............................................. Open at page → 7 Page 7 1. Introduction Reflectance, transmittance, and absorptance/emittance are essential optical properties of materials needed for optical science research and industrial applications. The interaction of light with matter is... Open at page → 8 Page 8 !!! !! ! ! !!!!!!!!!!!!! 2. Reflectance, Transmittance, and Absorptance/Emittance Reflection is the process by which radiant flux is returned at the boundary between two media (surface reflection) or at the interior of a... Open at page → 9 Page 9 3. Setups and measurements The typical setup of equipment for the calibration service 38075S is shown schematically in Fig. 1. In general, the primary spectral source has been a Digilab FTS-7000 1 commercial Fourier tran... Open at page → 10 Page 10 Figure 2: The Digilab FTS 7000 FTIR wavelength range in our setup is 0.8 µm to 50 µm and resolution is ≥ 0.5 cm -1 . It is configured for our system with a W–halogen lamp and coated quartz beam splitter for the near-IR s... Open at page → 11 Page 11 replaced by a similar FTIR, such as the Bruker Vertex 80v, available in the laboratory, without significant modification of the custom external systems described below. The spectrometer with its internal sample testing b... Open at page → 12 Page 12 3.1. “Conventional” transmittance measurements For transmittance (τ) measurements of fairly thin samples, which do not significantly modify the IR beam geometry, a modified version of the standard sample compartment geom... Open at page → 13 Page 13 Sample Detector Half- block Half- block Source Aperture Stop Field Filter Reference Stop Figure 3: Optical layout for the FTIR transmittance measurements as described in the text. 0.012 0.013 0.014 0.015 12 14 16 18 20 0... Open at page → 14 Page 14 A 2 mm room temperature pyroelectric detector was used with the 60A, while a 1 mm 77 K mercury–cadmium–telluride (MCT) detector was used with the DA-3. The beam geometry at the sample position was f/3 in the Bio-Rad and... Open at page → 15 Page 15 ! Optical Density 5 Cu:Ni on Si 4 3 Cu:Ni on Si 2 Ni:Cr on Si 1 Ni:Cr on Si 0 5 10 15 20 25 Wavelength (microns) Figure 5: Spectra of neutral density filter SRMs. 9 Open at page → 16 Page 16 A set of 10 samples for each OD level have been produced and the filters have been measured to determine the repeatability and reproducibility of the transmittance over a period of 6 months. The metal coatings have been... Open at page → 17 Page 17 Table 1: Uncertainty estimates for ND filter transmittances, in % of measured values Uncertainty source OD 1 OD 2 OD 3 OD 4 Type B Inter-reflections 0.2 0.3 0.3 0.3 Detector non-linearity 0.1 0.1 0.05 0.05 Detector non-e... Open at page → 18 Page 18 measured at 81 K and 94 K. A separate set of transmittance measurements at room temperature were performed for all four filters at normal incidence with an f/4 incident beam geometry. The sample temperatures were control... Open at page → 19 Page 19 Transmittance Transmittance 0.8 1 (a) Filter SN1 f/6.5 0.5 cm -1 resolution 296 K 94 K 84 K 81 K 0.6 0.4 0.2 0 700 720 740 760 Wavenumber (cm -1 ) 780 800 0.8 1 (b) Filter SN1 f/6.5 2 cm -1 resolution 296 K 94 K 84 K 81... Open at page → 20 Page 20 Transmittance Transmittance 0.8 1 (a) Filter SN2 f/6.5 0.5 cm -1 resolution 296 K 84 K 0.6 0.4 0.2 0 700 720 740 760 Wavenumber (cm -1 ) 780 800 0.8 1 (b) Filter SN2 f/6.5 2 cm -1 resolution 296 K 84 K 0.6 0.4 0.2 0 700... Open at page → 21 Page 21 Transmittance Transmittance 0.8 1 (a) Filter SN4 f/6.5 0.5 cm -1 resolution 296 K 84 K 0.6 0.4 0.2 0 700 720 740 760 Wavenumber (cm -1 ) 780 800 0.8 1 (b) Filter SN4 f/6.5 2 cm -1 resolution 296 K 84 K 0.6 0.4 0.2 0 700... Open at page → 22 Page 22 Transmittance Transmittance 0.8 1 (a) Filter SN28 f/6.5 0.5 cm -1 resolution 296 K 84 K 0.6 0.4 0.2 0 700 720 740 760 Wavenumber (cm -1 ) 780 800 0.8 1 (b) Filter SN28 f/6.5 2 cm -1 resolution 296 K 84 K 0.6 0.4 0.2 0 70... Open at page → 23 Page 23 the data taken at 81 K and 94 K for Filter SN 1. The 0.5 cm -1 data for these filters show Fabry- Perot fringes due to interference in the Ge substrates. The fringes are eliminated by reducing the spectral resolution to... Open at page → 24 Page 24 Filter SN1 296 K Resolution = 0.5 cm -1 1 (a) f/4 f/6.5 0.8 Transmittance Transmittance 0.6 0.4 0.2 0 700 720 740 760 Wavenumber (cm -1 ) 780 800 0.8 1 (b) Filter SN1 296 K Resolution = 2 cm -1 f/4 f/6.5 0.6 0.4 0.2 0 70... Open at page → 25 Page 25 Filter SN2 296 K Resolution = 0.5 cm -1 1 (a) f/4 f/6.5 0.8 Transmittance Transmittance 0.6 0.4 0.2 0 700 720 740 760 Wavenumber (cm -1 ) 780 800 0.8 1 (b) Filter SN2 296 K Resolution = 2 cm -1 f/4 f/6.5 0.6 0.4 0.2 0 70... Open at page → 26 Page 26 Filter SN4 296 K Resolution = 0.5 cm -1 1 (a) f/4 f/6.5 0.8 Transmittance Transmittance 0.6 0.4 0.2 0 700 720 740 760 Wavenumber (cm -1 ) 780 800 0.8 1 (b) Filter SN4 296 K Resolution = 2 cm -1 f/4 f/6.5 0.6 0.4 0.2 0 70... Open at page → 27 Page 27 Filter SN28 296 K Resolution = 0.5 cm -1 1 (a) f/4 f/6.5 0.8 Transmittance Transmittance 0.6 0.4 0.2 0 700 720 740 760 Wavenumber (cm -1 ) 780 800 0.8 1 (b) Filter SN28 296 K Resolution = 2 cm -1 f/4 f/6.5 0.6 0.4 0.2 0... Open at page → 28 Page 28 22! ! Table 2: Type-B estimated relative uncertainty components for transmittance measurements of the narrow-band filters. Detector nonlinearity 0.001 Inter-reflections 0.001 Beam-shifting from sample 0.004 Beam geometry... Open at page → 29 Page 29 23! ! The final uncertainties for the in-band transmittance are dominated by beam-shifting from the sample and FT phase error. A type-A component evaluated from the standard deviation of successive measurements of each f... Open at page → 30 Page 30 24! ! Table 3 lists uncertainty components in cm-1 for the filter band edge positions for the four measured filters due to instrument wavenumber error, temperature, angle of incidence, focusing geometry, non-uniformity,... Open at page → 31 Page 31 25! ! 3.2. The Infrared Reference Integrating Sphere (IRIS) setup The schematic in Fig. 14 shows the integrating sphere measurement geometry at the NIST FTIS facility for diffuse reflectance measurement; for diffuse tran... Open at page → 32 Page 32 26! ! Figure 14:!!Sphere measurement geometry for directional-hemispherical: single direction input and detection over all angles. The schematic shows the setup for Regular/diffuse measurement. For diffuse transmittance... Open at page → 33 Page 33 27! ! One of the authors, Leonard Hanssen, developed the absolute DHR method at NIST and designed the integrating sphere that was custom made and implemented the setup for the calibration service 38075 S. The complete de... Open at page → 34 Page 34 28! ! reasoning that most samples would have the reflected light encounter a sphere throughput somewhere in between the perfectly specular and perfectly diffuse case. For some samples, such as the DHR standards, a reduct... Open at page → 35 Page 35 29! ! hemisphere of output angles can also be used to obtain ργ,h. However, it is difficult to obtain sufficiently accurate BRDF over a sufficiently large fraction of the hemisphere (to viewing angles near grazing) to ob... Open at page → 36 Page 36 30! ! Figure 15: Photograph of the integrating sphere for absolute infrared spectral transmittance and reflectance. On the top is mounted an LN2 cooled MCT detector with a built-in compound hyperbolic concentrator and le... Open at page → 37 Page 37 31! ! The sphere has entrance, sample, and reference ports all centered on a great circle of the sphere as shown in Fig. 16. There also is a detector port, with its center located along the normal to the great circle. Th... Open at page → 38 Page 38 32! ! Figure 16: Schematic of the integrating sphere geometry. ! ! Open at page → 39 Page 39 33! ! reference ports are shown in Fig. 15. The baffles are critical to the sphere performance for characterization of diffuse samples. The spatial non-uniformity of the integrating sphere throughput has been evaluated a... Open at page → 40 Page 40 34! ! Figure 17: Sphere measurement geometries for reflectance and transmittance and rotation steps used to orient the sphere for each (a) reflectance measurement geometry, (c) reference measurement, and (e) transmittanc... Open at page → 41 Page 41 35! ! Stage #1 has its axis of rotation oriented parallel to the normal of the great circle formed by the entrance, sample and reference port centers, as well as passing through the edge of this circle. This base stage r... Open at page → 42 Page 42 36! ! In Fig. 17(a) a clockwise rotation about axis #1 turns the back of the sample to the beam in Fig. 17(b). An additional clockwise rotation about axis #2 places the (empty) reference port at the input beam focus in (... Open at page → 43 Page 43 37! ! By conservation of energy, the absolute absorptance is indirectly obtained by subtracting the sum of the absolute reflectance and transmittance from unity. The reflectance and transmittance measurements are made un... Open at page → 44 Page 44 38! ! requirements of 1 % uncertainty, shorter measurement times on the order of 10 min to 20 min will suffice. In addition to the various potential sources of error due to the Fourier transform spectrometer, [Appendix A... Open at page → 45 Page 45 39! ! ! Figure 18: Sample and reference port throughput comparison, the result of an empty sample port transmittance measurement. The curve represents the difference in detector signal for specularly transmitted and refl... Open at page → 46 Page 46 40! ! For specular samples, a correction must be made to the measured transmittance or reflectance values to account for the light from the sphere wall that is back-reflected to the sample (Figs. 17(a) or 17(b)) and lost... Open at page → 47 Page 47 41! ! !! Figure 19: Additive correction for specular samples made when using the IRIS; variation with sample reflectance. ! ! Open at page → 48 Page 48 42! ! !!! ! Figure 20:!Entrance port overfilling measurements in the near infrared and mid infrared setups.! ! Open at page → 49 Page 49 43! ! ! Figure 21: Sample port overfill measurement, the result of an empty sample port reflectance measurement. This is a characterization of the baseline measurement capability of the integrating sphere system. The res... Open at page → 50 Page 50 44! ! 3.2.4. Specular sample measurement results of ρ, τ, and α A number of samples of optical components have been characterized using the integrating sphere system including windows, filters and mirrors. Several exampl... Open at page → 51 Page 51 45! ! Figure 22: Transmittance, reflectance and absorptance (obtained from 1-ρ-τ) of several common IR window materials, ranging in index from 3.4 to 1.3: Si. ! Open at page → 52 Page 52 46! ! Figure 23: Transmittance, reflectance and absorptance (obtained from 1-ρ-τ) of several common IR window materials, ranging in index from 3.4 to 1.3: ZnSe. ! Open at page → 53 Page 53 47! ! Figure 24: Transmittance, reflectance and absorptance (obtained from 1-ρ-τ) of several common IR window materials, ranging in index from 3.4 to 1.3: KRS-5. ! Open at page → 54 Page 54 48! ! Figure 25: Transmittance, reflectance and absorptance (obtained from 1-ρ-τ) of several common IR window materials, ranging in index from 3.4 to 1.3: MgF2. ! Open at page → 55 Page 55 49! ! range. At 12.5 µm, both the reflectance and the transmittance are 0, at which the absorption coefficient is substantial (τ ! 0) and the index is close to 1 (ρ! 0). A closer examination of the indirectly measured ab... Open at page → 56 Page 56 50! ! ! ! Figure 26: Expanded plot of spectra shown in Fig. 21 highlighting regions with absorptance near zero: Si. The spectra, in regions where k should be negligible, [11] result from a combination of (1) cumulative m... Open at page → 57 Page 57 51! ! Figure 27: Expanded plot of spectra shown in Fig. 21 highlighting regions with absorptance near zero: ZnSe. The spectra, in regions where k should be negligible, [11] result from a combination of (1) cumulative mea... Open at page → 58 Page 58 52! ! Figure 28: Expanded plot of spectra shown in Fig. 21 highlighting regions with absorptance near zero: KRS-5. The spectra, in regions where k should be negligible, [11] result from a combination of (1) cumulative me... Open at page → 59 Page 59 53! ! ! Figure 29: Expanded plot of spectra shown in Fig. 21 highlighting regions with absorptance near zero: MgF2. The spectra, in regions where k should be negligible, [11] result from a combination of (1) cumulative m... Open at page → 60 Page 60 54! ! Figure 30: Gold electroplated mirror reflectance. Open at page → 61 Page 61 55! ! 3.2.4.1. Advantages of using IRIS for measurements of ρ, τ and α of specular samples The benefits of using the integrating sphere for more accurate detection of light played an important role in the NIST design and... Open at page → 62 Page 62 56! ! 3.2.5 Absolute total scatter (diffuse reflectance, ρd; diffuse transmittance, τd) measurements. ! The IRIS described in Sec. 3.2.3 is an absolute DHR measurement setup and the sphere will collect all or most of the... Open at page → 63 Page 63 57! ! ! Figure 31: Schematic of the integrating sphere geometry for diffuse component measurement at normal incidence. Open at page → 64 Page 64 58! ! uniform. The uncertainty of the DHR result will then depend on the size of the non-uniformity and the extent to which it can be corrected for, which is described in the following section. result will then depend on... Open at page → 65 Page 65 59! ! ! 1.00 1.01 1.02 1.03 1.04 1.05 0 5 10 15 20 Scale Factor Mid IR Scale Factor Near IR Calibration Factor Wavelength (µm) Due to port loss Figure 32: Calibration curves for the near IR and mid IR for a Lambertian (i... Open at page → 66 Page 66 60! ! 0.85 0.90 0.95 1.00 0 5 10 15 20 Rough Gold 1 Rough Gold 2 Uncorrected Reflectance Wavelength (µm) (a) 0.85 0.90 0.95 1.00 0 5 10 15 20 Rough Gold 1 Rough Gold 2 "Corrected" Reflectance Wavelength (µm) (b) Figure 3... Open at page → 67 Page 67 61! ! Table 4 shows the uncertainty budget for absolute DHR measurements of a non-specular sample. The dominant component of uncertainty is that due to the spatial non-uniformity of the integrating sphere. This component... Open at page → 68 Page 68 62! ! Table 4: Uncertainty budget for DHR measurement of a non-specular sample ! Uncertainty source Value (unit less) Type B Standard Uncertainty Component Inter-reflections 0.0002 Detector nonlinearity 0.0006 Atmospheri... Open at page → 69 Page 69 63! ! Figure 34: Optical layout of the goniometric reflectometer system described in text. OAP, 90° off-axis paraboloidal mirror; A, variable aperture plate; M, folding mirror; P, polarizer; RS, rotation stage; TS, trans... Open at page → 70 Page 70 64! ! inner and outer goniometer stages is controlled using a small diode laser and quadrant detector system. Once the system is aligned, the sample is held on the axis of rotation of the goniometer on which the detector... Open at page → 71 Page 71 65! ! Figure 35: IGRT setup and the cryostat to hold samples at chosen temperature ! ! Open at page → 72 Page 72 66! ! Figure 36: Photograph of goniometer showing the two detector cryostats mounted on the outer rotation stage. The small InSb detector system is visible behind and to the left of the 50 cm tall liquid-He cryostat hous... Open at page → 73 Page 73 67! ! which the BIB detector cryostat is mounted. This is used to manually position the detector relative to the input beam. 3.3.2. Calibration measurement procedure – Example of a gold mirror sample For the reflectance... Open at page → 74 Page 74 68! ! Figure 37: Comparison of measured reflectance values for a gold mirror with predicted values using two different sets of literature values for n and k of gold. (a) Measurements on a 25.4 mm diameter electroplated g... Open at page → 75 Page 75 69! ! 4.0. Measurement Assurance The measurement assurance for the calibration service 38075S is reviewed as two parts. The first part deals with the work done and published on the sources of error in the measurement pro... Open at page → 76 Page 76 70! ! 4.2 Internal and external intercomparisons 4.2.1 Internal w/ STARR / monochromator/transmittance/reflectance Appendix E describes the inter-comparison for the regular reflectance and transmittance measurements with... Open at page → 77 Page 77 71! ! 5.0 Template for Calibration Report Appendix I shows a template of a calibration report.! 6.0 References [1] J.M. Palmer, "The Measurement of Transmission, Absorption, Emission and Reflection," in Handbook of Optic... Open at page → 78 Page 78 72! ! [12] D. B. Chenault, K. A. Snail, and L. M. Hanssen, “Improved integrating-sphere throughput with a lens and nonimaging concentrator,” Appl. Opt. 34, 7959-7964 (1995). [13] L. M. Hanssen, A. V. Prokhorov, V. B. Kro... Open at page → 79 Page 79 Appendix A. Open at page → 80 Page 80 Testing the radiometric accuracy of Fourier transform infrared transmittance measurements S. G. Kaplan, L. M. Hanssen, and R. U. Datla We have investigated the ordinate scale accuracy of ambient temperature transmittance... Open at page → 81 Page 81 2. FT-IR Measurements A. Experimental Setup Transmittance measurements over the wavelength range from 2 to 25mm at near-normal incidence were performed with a Bio-Rad FTS-60A scanning FT-IR spectrometer, by use of a cera... Open at page → 82 Page 82 wavelengths shorter than 15mm, half of the cutoff wavelength of the KBr:Ge beam splitter. For wavelengths shorter than 12mm, there are apparent Fabry±Perot fringes in the transmittance with an amplitude as high as 0.5% a... Open at page → 83 Page 83 geometry and that~b!the maximum incident angle is increased to;20É, with the weighted average angle increased to;12É. ~2!A second method~which was used here!is to place a half-beam block near the input focusing mir- ror.... Open at page → 84 Page 84 heated source aperture can still over®ll the sample area, producing spurious transmittance results. This effect is demonstrated in Fig. 3, in which mea- surements of a 15-mm aperture placed at the sample position with a... Open at page → 85 Page 85 0.5 V. The scatter~;0.4%!in the four data points at the lowest power levels is reproducible~not the result of random drifts in the interferometerÐthe error bars show the statistical uncertainty components!, but the origi... Open at page → 86 Page 86 sample shown in Fig. 5~a!, the transmittance mea- surement was made relative to the empty beam with the setup with reduced radiometric errors described in the previous section. This sample shows a fairly ¯at attenuation,... Open at page → 87 Page 87 on this and similar FT-IR instruments with more sensitive photoconductive detectors, we believe the intrinsic offset to be less than 10 27 in transmit- tance, 15 so we choose not to include it in the uncer- tainty budget... Open at page → 88 Page 88 multiple passes through the interferometer result in false signals of alternating sign at harmonics of the actual~physical!wave number of a particular spec- tral component. 3,4 Other interre¯ections, if they in- volve th... Open at page → 89 Page 89 5. Nonsource Emission Errors Errors due to source-aperture emission's over®lling the sample were substantially reduced on the place- ment of ®eld stop A2~Fig. 1!before the sample. Fig- ure 3 shows that there may be a 0.1... Open at page → 90 Page 90 points, this error source is not expected to be impor- tant in our analysis. 13. Interferometer Phase ErrorsyPhase Drift Improper phase correction of the interferogram can cause a number of errors, including a false slop... Open at page → 91 Page 91 5. Sample Nonuniformity We tested the uniformity of the samples by moving the samples relative to the incident beam to several different positions and estimating a standard devia- tion in the resulting transmittance valu... Open at page → 92 Page 92 ton, J. Drab, and H. S. Barr, ªAccurate infrared transmittance measurements on optical ®lters using an FT-IR spectrometer,º Appl. Opt.29,2908 ±2912~1980!. 2. D. B. Chase, ªNonlinear detector response in FT-IR,º Appl. Spe... Open at page → 93 Page 93 Appendix B. Open at page → 94 Page 94 Linearity characterization of NIST's infrared spectral regular transmittance and reflectance scales Leonard Hanssen and Simon Kaplan Optical Technology Division, NIST Gaithersburg, MD, USA 20899-8442 ABSTRACT In the past... Open at page → 95 Page 95 standard detectors at NIST.) We achieve the variation of input flux level by use of an aperture plate shown in Figure 1, using 14 apertures ranging in diameter from 1 to 8 mm. The aperture plate is located at an intermed... Open at page → 96 Page 96 (HgCdTe) with non-imaging optics designed for high throughput. In particular, p and 'r of specular samples can be measured with an uncertainty of -O.25%.[2] A pair of off-axis paraboloidal mirrors (OAPs) is used to provi... Open at page → 97 Page 97 Cl) Figure 3 .Relativeinput flux obtained for the sample and reference spectra used to determine the Silicon transmittance. The four curves denote the maximum signal values in the spectra for both the MIR and NIR configu... Open at page → 98 Page 98 Reference Signal (V) Figure4. The mean normalized transmittance as a function of maximum signal in the reference measurement (for all values of source aperture diameter) for both the MIR and NIR configurations. The trans... Open at page → 99 Page 99 - j L JT Rence' 0 Sample - — > U) C 0 IU 9995 (b) :1 II iiiiiilII 111111 0.11 Signal (V)Signal (V) Figure5. Relativeresponsivity for the FT-JR-sphere system for the (a) near-infrared and (b) mid-infrared configurations.... Open at page → 100 Page 100 Appendix C. Open at page → 101 Page 101 Integrating-sphere system and method for absolute measurement of transmittance, reflectance, and absorptance of specular samples Leonard Hanssen An integrating-sphere system has been designed and constructed for multiple... Open at page → 102 Page 102 or more. 4 With considerable effort to achieve accu- rate alignment, excellent results can be achieved for standards quality samples. However, even in these cases, characteristics of the sample surface can limit ultimate... Open at page → 103 Page 103 a point directly opposite the entrance port!. Baf¯es separating the detector port and the detector ®eld-of- view region from the sample and the reference ports are shown in Fig. 2. The baf¯es are critical to the sphere p... Open at page → 104 Page 104 away from the base-stage axis exactly equal to the sphere radius. The integrating sphere is mounted to the rotation table of stage 2 so that the stage's axis of rotation is along the sphere axis that includes the cen- te... Open at page → 105 Page 105 for the re¯ectance and the transmittance measure- ments. For a uniform sample with identical front and back surfaces, the side of incidence is immaterial. For samples with some asymmetry that is due to, for example, a co... Open at page → 106 Page 106 obtained in the reference measurement was used for correction of the sample empty-port measurement. The remaining important sources of error are re- lated to the FTIR spectrometer, detector, electronics, and FT processin... Open at page → 107 Page 107 spectral features are seen that can be attributed to contaminants, primarily on the surface, such as wa- ter and hydrocarbon modes. Features from 6 to 7 mm,9to10mm, and 12.5mm appear in the ZnSe and the KRS-5 spectra. Th... Open at page → 108 Page 108 7. Discussion and Conclusions The bene®ts of using the integrating sphere for more accurate detection of light are used in the design and the development of a device for absolute measure- ment of transmittance, re¯ectanc... Open at page → 109 Page 109 beam geometry interaction ~beam deviation, de¯ection, and focus shift!. 11 The integrating-sphere system is not suitable for high-sample-throughput applications. For these ap- plications other instrumentation designed fo... Open at page → 110 Page 110 Appendix D. Open at page → 111 Page 111 Infrared regular re¯ectance and transmittance instrumentation and standards at NIST S.G. Kaplan * , L.M. Hanssen Optical Technology Division, NIST, Gaithersburg, MD 20899, USA Received 17 June 1998; accepted 25 August 19... Open at page → 112 Page 112 among FT-IR, grating monochromator, and laser- based systems, and the development of standard refer- ence materials for regular IR transmittance. FT-IR spectrometers are the most widely used instruments for routine IRTan... Open at page → 113 Page 113 are used to eliminate inter-re¯ections among the sample, detector and interferometer. Neutral-density or band pass ®lters are placed (tilted, to avoid inter- re¯ections) before the sample position, or used as the referen... Open at page → 114 Page 114 in the reference measurement strikes the surface of the sphere in an optically equivalent position to that of the specular beam from the sample. Thus the ratio of the two measurements provides an absolute measurement [1]... Open at page → 115 Page 115 increase the size of the transmitted or re¯ected spot on the sphere wall compared to the reference spot. To test the accuracy for lower signal levels, an intercompar- ison with a ``conventional'' measurement was per- for... Open at page → 116 Page 116 2.3. T/R measurements with goniometer Another method for measuring absolute re¯ectance is the goniometer arrangement shown in Fig. 1. In this set up, the beam is re¯ected from the sample directly onto the detector. Then,... Open at page → 117 Page 117 polarizers. As shown in Fig. 1, MgF2pseudo-zero- order waveplates can also be placed in the optical train to realize a rotating-retarder polarimeter [20], which has been used to measure the complete Mueller matrix of wir... Open at page → 118 Page 118 depending on the type of the sample. A goniometer system has also been constructed and used for angle, polarization, and temperature dependent measure- ments. A set of neutral density ®lters has been pro- duced to serve... Open at page → 119 Page 119 Appendix E. Open at page → 120 Page 120 metrologia Comparisonofnear-infraredtransmittance andreectancemeasurementsusingdispersive andFouriertransformspectrophotometers S.G.Kaplan,L.M.Hanssen,E.A.Early, M.E.NadalandD.Allen Abstract.Aspectrophotometerbasedonani... Open at page → 121 Page 121 S.G.Kaplanetal. whetherornottheyfallwithinthecombinedexpanded uncertaintyofthetwomeasurements.Wealsoconsider anydifferencesinbeamgeometry,polarizationand spectralresolutionamongthevarioussystemsand estimateanydifferences... Open at page → 122 Page 122 Comparisonofnear-infraredtransmittanceandreectancemeasurements theaverageabsorptionpathlengthinthedispersive measurement.Thespotdiameteratthesampleposition isapproximately5mm.Thebeampolarizationhas beencheckedusingwire-... Open at page → 123 Page 123 S.G.Kaplanetal. givenbythenetsamplesignaldividedbytheaverage netopensignal. Individualsampleswerecleanedwithanairbulb andmountedinacommerciallensholderwiththe beamcentredonthefrontsurfaceofthetestitemat normalincidence.T... Open at page → 124 Page 124 Comparisonofnear-infraredtransmittanceandreectancemeasurements todifferentincidentanglesandopticalpathlengths inthematerials.Wealsowantedtotestbothlarge (near1)andsmall(<0.1)valuesontheradiometric scaletoassesslinearity... Open at page → 125 Page 125 S.G.Kaplanetal. Figure5.ComparisonofFTIRandmonochromator measurementsofa2mmthickabsorbing-glassŽlter. (a)measuredtransmittances,withopencirclesshowing monochromatordataandsolidcurveshowingFTIRdata; (b)differencemono FTIR... Open at page → 126 Page 126 Comparisonofnear-infraredtransmittanceandreectancemeasurements Figure7.ComparisonofFTIRandmonochromator measurementsofa0.25mmthickSiwaferwithaNiCr coating.(a)measuredtransmittances,withopencircles showingmonochromatorda... Open at page → 127 Page 127 S.G.Kaplanetal. Figure9.ComparisonofFTIRandSTARRreectance measurementsofablack-glassmirror.(a)measured reectanceswithSTARRasopensquaresandFTIRas solidline;(b)difference STARR FTIRbetweenthe twomeasurements(squares)andc... Open at page → 128 Page 128 Appendix F. Open at page → 129 Page 129 INSTITUTE OFPHYSICSPUBLISHING METROLOGIA Metrologia40(2003) S55–S59 PII: S0026-1394(03)57649-6 NIST–NPLcomparisonofmid-infrared regulartransmittanceandreflectance C J Chunnilall 1 ,FJJClarke 1 , M P Smart 1 , L M Hanssen... Open at page → 130 Page 130 C J Chunnilallet al 100×τ Figure 1.Typical transmittance spectrum of 1 mm of Schott NG11 glass. known from some 50 years’ work in visible region standards to be very stable for transmittance, provided that it is not clea... Open at page → 131 Page 131 NIST–NPL comparison of mid-infrared regular transmittance and reflectance Table 2.Summary of results for transmittance comparison after inclusion of thermochromism and tilt corrections and their uncertainties. 100×Transmi... Open at page → 132 Page 132 C J Chunnilallet al BK 7 NiCr 1000 2000 3000 4000 Wavenumber/cm -1 Al 100×(NPL - NIST) -0.4 -0.2 0.0 0.2 0.4 -1.0 -0.5 0.0 0.5 1.0 -0.4 -0.2 0.0 0.2 0.4 Figure 3.Spectra comparing the results and uncertainties of the refl... Open at page → 133 Page 133 NIST–NPL comparison of mid-infrared regular transmittance and reflectance Table 6.NPL uncertainty budget for BK7 glass measurement at the 40% reflectance peak. Absolute Relative calibration of calibration of reference comp... Open at page → 134 Page 134 Appendix G. Open at page → 135 Page 135 Comparison of mid-infrared absorptance scales at NMIJ and NIST J. Ishii National Metrology Institute of Japan (NMIJ) / AIST, Tsukuba, Japan L. M. Hanssen National Institute of Standards and Technology (NIST), Gaithersbur... Open at page → 136 Page 136 were 45 mm diameter discs of approximately 1 mm thickness. The samples were measured first at NMIJ and then sent to NIST for measurement. Results and discussions Figures 1 to 3 summarize the results measured by NMIJ and... Open at page → 137 Page 137 Professor Horst Cerjak, 19.12.2005 1 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance APPENDIX H Results of a Nationwide Int... Open at page → 138 Page 138 Professor Horst Cerjak, 19.12.2005 2 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance I.Background II.Intercomparision Detai... Open at page → 139 Page 139 Professor Horst Cerjak, 19.12.2005 3 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance EO-IR Calibration and Characterization... Open at page → 140 Page 140 Professor Horst Cerjak, 19.12.2005 4 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance I.Background II.Intercomparision Detai... Open at page → 141 Page 141 Professor Horst Cerjak, 19.12.2005 5 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance Intercomparison Structure •NIST is Pil... Open at page → 142 Page 142 Professor Horst Cerjak, 19.12.2005 6 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance Final Participant List Open at page → 143 Page 143 Professor Horst Cerjak, 19.12.2005 7 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance Participant Survey Results Survey Resp... Open at page → 144 Page 144 Professor Horst Cerjak, 19.12.2005 8 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance I.Background II.Intercomparision Detai... Open at page → 145 Page 145 Professor Horst Cerjak, 19.12.2005 9 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance Intercomparison Transfer Standard Samp... Open at page → 146 Page 146 Professor Horst Cerjak, 19.12.2005 10 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance Intercomparison Transfer Standard Sam... Open at page → 147 Page 147 Professor Horst Cerjak, 19.12.2005 11 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance Sample Characterisation Gold Mirror,... Open at page → 148 Page 148 Professor Horst Cerjak, 19.12.2005 12 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance Sample Characterisation Rough Gold -... Open at page → 149 Page 149 Professor Horst Cerjak, 19.12.2005 13 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance Sample Characterisation Krylon Silver... Open at page → 150 Page 150 Professor Horst Cerjak, 19.12.2005 14 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance Intercomparison Specifics •Quantity:... Open at page → 151 Page 151 Professor Horst Cerjak, 19.12.2005 15 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance I.Background II.Intercomparision Deta... Open at page → 152 Page 152 Professor Horst Cerjak, 19.12.2005 16 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance SxxA – Gold Mirror Samples I 21 Curve... Open at page → 153 Page 153 Professor Horst Cerjak, 19.12.2005 17 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance SxxA – Gold Mirror Samples II Compari... Open at page → 154 Page 154 Professor Horst Cerjak, 19.12.2005 18 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance SxxB – Silicon Carbide Samples I Mino... Open at page → 155 Page 155 Professor Horst Cerjak, 19.12.2005 19 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance SxxB – Silicon Carbide Samples II Sig... Open at page → 156 Page 156 Professor Horst Cerjak, 19.12.2005 20 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance DxxA – Rough Gold Samples I Some chan... Open at page → 157 Page 157 Professor Horst Cerjak, 19.12.2005 21 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance DxxA – Rough Gold Samples II Most (bu... Open at page → 158 Page 158 Professor Horst Cerjak, 19.12.2005 22 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance DxxC – Nextel Black Paint Samples I L... Open at page → 159 Page 159 Professor Horst Cerjak, 19.12.2005 23 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance DxxC – Nextel Black Paint Samples II... Open at page → 160 Page 160 Professor Horst Cerjak, 19.12.2005 24 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance DxxD – Krylon Silver Paint Samples I... Open at page → 161 Page 161 Professor Horst Cerjak, 19.12.2005 25 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance DxxD – Krylon Silver Paint Samples II... Open at page → 162 Page 162 Professor Horst Cerjak, 19.12.2005 26 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance NIST method for Absolute Diffuse Refl... Open at page → 163 Page 163 Professor Horst Cerjak, 19.12.2005 27 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance DxxD – Krylon Silver Paint BRDF Open at page → 164 Page 164 Professor Horst Cerjak, 19.12.2005 28 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance Dependence of Port Loss on BRDF Examp... Open at page → 165 Page 165 Professor Horst Cerjak, 19.12.2005 29 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance Correction Curves for Range of BRDFs Open at page → 166 Page 166 Professor Horst Cerjak, 19.12.2005 30 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance I.Background II.Intercomparision Deta... Open at page → 167 Page 167 Professor Horst Cerjak, 19.12.2005 31 Boris WILTHAN CORM 2011 – Optical Properties of Materials NIST Final Results of a Nationwide Inter-Laboratory Comparison of Infrared Reflectance Conclusions and Future Directions Na... Open at page → 168 Page 168 Calibration Date: XXX, XXX NIST Test No.: XXXXXX Page 1 of 4 APPENDIX I REPORT OF CALIBRATION 38075S Special Tests Infrared Reflectance, Transmittance, and Emittance of Materials for Diffuse Gold Sample S/N XXXXXX Submit... Open at page → 169 Page 169 REPORT OF CALIBRATION Manufacturer: Unknown 38075S Special Tests Infrared Reflectance, Model #: n/a Transmittance, and Emittance of Materials Serial #: n/a National Institute of Metrology Calibration Date: Month Date, Ye... Open at page → 170 Page 170 REPORT OF CALIBRATION Manufacturer: Unknown 38075S Special Tests Infrared Reflectance, Model #: n/a Transmittance, and Emittance of Materials Serial #: n/a National Institute of Metrology Calibration Date: Month Date, Ye... Open at page → 171 Page 171 REPORT OF CALIBRATION Manufacturer: Unknown 38075S Special Tests Infrared Reflectance, Model #: n/a Transmittance, and Emittance of Materials Serial #: n/a National Institute of Metrology Calibration Date: Month Date, Ye... Open at page →