Material Properties

Five Schott Glass Types

The following paragraphs list the most important optical and physical constants for Schott optical glass types BK7, SF11, LaSFN9, BaK1, and F2. These types are used in most Melles Griot simple lens products and prisms. Index of refraction and transmission, as well as the most commonly required chemical characteristics and mechanical constants, are listed. Further numerical data and a more detailed discussion of the various testing processes can be found in the Schott Optical Glass catalog. The index of refraction data were obtained by using the constants listed below together with the dispersion formula. The constants were determined through the index-of-refraction measurements of a typical melt for each glass type. Note that the dispersion formula is valid only within the wavelength range listed. It can be used to interpolate refractive index at other wavelengths within this range (to a precision of 1 x 10-5 or better), but it should not be used to extrapolate to wavelengths beyond this range. Furthermore, the actual melt-to-melt tolerance on the index of refraction typically is about ±0.001.

BK7 Glass

Abbé Constant: 64.17 Density:2.51 g/cm-3 Young's Modulus: 8.20 x 109 dynes/mm2 Poisson's Ratio: 0.206 Coefficient of Thermal Expansion (-30° to +70°C): 7.1 x 10-6/°C Coefficient of Thermal Expansion (20° to 3000°C): 8.3 x 10-6/°C Stress Birefringence, (Yellow Light): 10 nm/cm Homogeneity within Melt: ±1x10-4 Striae Grade (MIL-G-174-A): A Transformation Temperature: 557°C Climate Resistance: 2 Stain Resistance: 0 Acid Resistance: 1.0 Alkali Resistance: 2.0 Phosphate Resistance: 2.3 Knoop Hardness: 610 Dispersion Constants:      B1 = 1.03961212      B2 = 2.31792344x10-1      B3 = 1.01046945      C1 = 6.00069867x10-3      C2 = 2.00179144x10-2      C3 = 1.03560653x102

External transmission for 10-mm-thick BK7 glass

Physical Constants of BK7 Glass Wavelength (nm) Refractive Index n Fraunhofer Designation Source Spectral Region 351.1 1.53894 -- Ar laser UV 363.8 1.53649 -- Ar laser UV 404.7 1.53024 h Hg arc Violet 435.8 1.52668 g Hg arc Blue 441.6 1.52611 -- HeCd laser Blue 457.9 1.52461 -- Ar laser Blue 465.8 1.52395 -- Ar laser Blue 472.7 1.52339 -- Ar laser Blue 476.5 1.52309 -- Ar laser Blue 480.0 1.52283 F' Cd arc Blue 486.1 1.52238 F H2 arc Blue 488.0 1.52224 -- Ar laser Blue 496.5 1.52165 -- Ar laser Green 501.7 1.52130 -- Ar laser Green 514.5 1.52049 -- Ar laser Green 532.0 1.51947 -- Nd laser Green 546.1 1.51872 e Hg arc Green 587.6 1.51680 d He arc Yellow 589.3 1.51673 D Na arc Yellow 632.8 1.51509 -- HeNe laser Red 643.8 1.51472 C' Cd arc Red 656.3 1.51432 C H2 arc Red 694.3 1.51322 -- Ruby laser Red 786.0 1.51106 -- -- IR 821.0 1.51037 -- -- IR 830.0 1.51020 -- GaAIAs laser IR 852.1 1.50980 s Ce arc IR 904.0 1.50893 -- GaAS laser IR 1014.0 1.50731 t Hg arc IR 1060.0 1.50669 -- Nd laser IR 1300.0 1.50370 -- InGaAsP laser IR 1500.0 1.50127 -- -- IR 1550.0 1.50065 -- -- IR 1970.1 1.49495 -- Hg arc IR 2325.4 1.48921 -- Hg arc IR

SF11 Glass

Abbé Constant: 25.76 Density: 4.74 g/cm-3 Young's Modulus: 6.60 x 109 dynes/mm2 Poisson's Ratio: 0.235 Coefficient of Thermal Expansion (-30° to +70°C): 6.1 x 10-6/°C Coefficient of Thermal Expansion (20° to 3000°C): 6.8 x 10-6/°C Stress Birefringence, (Yellow Light): 10 nm/cm Melt-to-Melt Mean Index Tolerance: ±0.001 Homogeneity within Melt: ±1 x 10-4 Striae Grade (MIL-G-174-A): A Transformation Temperature: 505°C Climate Resistance: 1 Stain Resistance: 0 Acid Resistance: 1.0 Alkali Resistance: 1.2 Phosphate Resistance: 1.0 Knoop Hardness: 450 Dispersion Constants:      B1 = 1.73848403      B2 = 3.11168974x10-1      B3 = 1.17490871      C1 = 1.36068604x10-2      C2 = 6.15960463x10-2      C3 = 1.21922711x102

External transmission for 10-mm-thick SF11 glass

Physical Constants of SF11 Glass Wavelength (nm) Refractive Index n Fraunhofer Designation Source Spectral Region 404.7 1.84208 h Hg arc Violet 435.8 1.82518 g Hg arc Blue 441.6 1.82259 -- HeCd laser Blue 457.9 1.81596 -- Ar laser Blue 465.8 1.81307 -- Ar laser Blue 472.7 1.81070 -- Ar laser Blue 476.5 1.80946 -- Ar laser Blue 480.0 1.80834 F' Cd arc Blue 486.1 1.80645 F H2 arc Blue 488.0 1.80590 -- Ar laser Blue 496.5 1.80347 -- Ar laser Green 501.7 1.80205 -- Ar laser Green 514.5 1.79880 -- Ar laser Green 532.0 1.79479 -- Nd laser Green 546.1 1.79190 e Hg arc Green 587.6 1.78472 d He arc Yellow 589.3 1.78446 D Na arc Yellow 632.8 1.77862 -- HeNe laser Red 643.8 1.77734 C' Cd arc Red 656.3 1.77599 C H2 arc Red 694.3 1.77231 -- Ruby laser Red 786.0 1.76558 -- -- IR 821.0 1.76359 -- -- IR 830.0 1.76311 -- GaAIAs laser IR 852.1 1.76200 s Ce arc IR 904.0 1.75970 -- GaAs laser IR 1014.0 1.75579 t Hg arc IR 1060.0 1.75445 -- Nd laser IR 1300.0 1.74901 -- InGaAsP laser IR 1500.0 1.74554 -- -- IR 1550.0 1.74474 -- -- IR 1970.1 1.73843 -- Hg arc IR 2325.4 1.73294 -- Hg arc IR

LaSFN9 Glass Abbé Constant: 32.17 Density: 4.44 g/cm-3 Young's Modulus: 1.09 x 1010 dynes/mm2 Poisson's Ratio: 0.286 Coefficient of Thermal Expansion (-30° to +70°C): 7.4 x 10-6/°C Coefficient of Thermal Expansion (20 °to 3000°C): 8.4 x 10-6/°C Stress Birefringence, (Yellow Light): 10 nm/cm Melt-to-Melt Mean Index Tolerance: ±0.002 Homogeneity within Melt: ±1 x 10-4 Striae Grade (MIL-G-174-A): A Transformation Temperature: 703°C Climate Resistance: 2 Stain Resistance: 0 Acid Resistance: 2.0 Alkali Resistance: 1.0 Phosphate Resistance: 1.0 Knoop Hardness: 630 Dispersion Constants:      B1 = 1.97888194      B2 = 3.20435298x10-1      B3 = 1.92900751      C1 = 1.18537266x10-2      C2 = 5.27381770x10-2      C3 = 1.66256540x102

External transmission for 10-mm-thick LaSFN9 glass

Physical Constants of LaSFN9 Glass Wavelength (nm) Refractive Index n Fraunhofer Designation Source Spectral Region 404.7 1.89844 h Hg arc Violet 435.8 1.88467 g Hg arc Blue 441.6 1.88253 -- HeCd laser Blue 457.9 1.87700 -- Ar laser Blue 465.8 1.87458 -- Ar laser Blue 472.7 1.87259 -- Ar laser Blue 476.5 1.87153 -- Ar laser Blue 480.0 1.87059 F' Cd arc Blue 486.1 1.86899 F H2 arc Blue 488.0 1.86852 -- Ar laser Blue 496.5 1.86645 -- Ar laser Green 501.7 1.86524 -- Ar laser Green 514.5 1.86245 -- Ar laser Green 532.0 1.85901 -- Nd laser Green 546.1 1.85651 e Hg arc Green 587.6 1.85025 d He arc Yellow 589.3 1.85002 D Na arc Yellow 632.8 1.84489 -- HeNe laser Red 643.8 1.84376 C' Cd arc Red 656.3 1.84256 C H2 arc Red 694.3 1.83928 -- Ruby laser Red 786.0 1.83323 -- -- IR 821.0 1.83142 -- -- IR 830.0 1.83098 -- GaAIAs laser IR 852.1 1.82997 s Ce arc IR 904.0 1.82785 -- GaAS laser IR 1014.0 1.82420 t Hg arc IR 1060.0 1.82293 -- Nd laser IR 1300.0 1.81764 -- InGaAsP laser IR 1500.0 1.81412 -- -- IR 1550.0 1.81329 -- -- IR 1970.1 1.80657 -- Hg arc IR 2325.4 1.80055 -- Hg arc IR

BaK1 Glass Abbé Constant: 57.55 Density: 3.19 g/cm-3 Young's Modulus: 7.30 x 109 dynes/mm2 Poisson's Ratio: 0.252 Coefficient of Thermal Expansion (-30° to +70°C): 7.6 x 10-6/°C Coefficient of Thermal Expansion (20° to 3000°C): 8.6 x 10-6/°C Stress Birefringence, (Yellow Light): 10 nm/cm Melt-to-Melt Mean Index Tolerance: ±0.001 Homogeneity within Melt: ±1 x 10-4 Striae Grade (MIL-G-174-A): A Transformation Temperature: 592°C Climate Resistance: 2 Stain Resistance: 1 Acid Resistance: 3.3 Alkali Resistance: 1.2 Phosphate Resistance: 2.0 Knoop Hardness: 530 Dispersion Constants:      B1 = 1.12365662      B2 = 3.09276848x10-1      B3 = 8.81511957x10-1      C1 = 6.44742752x10-3      C2 = 2.22284402x10-2      C3 = 1.07297751x102

External transmission for 10-mm-thick LaSFN9 glass

Physical Constants of BAK1 Glass Wavelength (nm) Refractive Index n Fraunhofer Designation Source Spectral Region 351.1 1.60062 -- Ar laser UV 363.8 1.59744 -- Ar laser UV 404.7 1.58941 h Hg arc Violet 435.8 1.58488 g Hg arc Blue 441.6 1.58415 -- HeCd laser Blue 457.9 1.58226 -- Ar laser Blue 465.8 1.58141 -- Ar laser Blue 472.7 1.58071 -- Ar laser Blue 476.5 1.58034 -- Ar laser Blue 480.0 1.58000 F' Cd arc Blue 486.1 1.57943 F H2 arc Blue 488.0 1.57927 -- Ar laser Blue 496.5 1.57852 -- Ar laser Green 501.7 1.57809 -- Ar laser Green 514.5 1.57707 -- Ar laser Green 532.0 1.57580 -- Nd laser Green 546.1 1.57487 e Hg arc Green 587.6 1.57250 d He arc Yellow 589.3 1.57241 D Na arc Yellow 632.8 1.57041 -- HeNe laser Red 643.8 1.56997 C' Cd arc Red 656.3 1.56949 C H2 arc Red 694.3 1.56816 -- Ruby laser Red 786.0 1.56564 -- -- IR 821.0 1.56485 -- -- IR 830.0 1.56466 -- GaAIAs laser IR 852.1 1.56421 s Ce arc IR 904.0 1.56325 -- GaAS laser IR 1014.0 1.56152 t Hg arc IR 1060.0 1.56088 -- Nd laser IR 1300.0 1.55796 -- InGaAsP laser IR 1500.0 1.55575 -- -- IR 1550.0 1.55520 -- -- IR 1970.1 1.55032 -- Hg arc IR 2325.4 1.54556 -- Hg arc IR

F2 Glass Abbé Constant: 36.37 Density: 3.61 g/cm-3 Young's Modulus: 5.70 x 109 dynes/mm2 Poisson's Ratio: 0.220 Coefficient of Thermal Expansion (-30° to +70°C): 8.2x10-6/°C Coefficient of Thermal Expansion (20° to 3000°C): 9.2 x 10-6/°C Stress Birefringence, (Yellow Light): 10 nm/cm Melt-to-Melt Mean Index Tolerance: ±0.001 Homogeneity within Melt: ±1 x 10-4 Striae Grade (MIL-G-174-A): A Transformation Temperature: 438°C Climate Resistance: 1 Stain Resistance: 0 Acid Resistance: 1.0 Alkali Resistance: 1.3 Phosphate Resistance: 1.3 Knoop Hardness: 420 Dispersion Constants:      B1 = 1.34533359      B2 = 2.09073176x10-1      B3 = 9.37357162x10-1      C1 = 9.97743871x10-3      C2 = 4.70450767x10-2      C3 = 1.11886764x102

External transmission for 10-mm-thick F2 glass

Physical Constants of F2 Glass Wavelength (nm) Refractive Index n Fraunhofer Designation Source Spectral Region 351.1 1.67359 -- Ar laser UV 363.8 1.66682 -- Ar laser UV 404.7 1.65064 h Hg arc Violet 435.8 1.64202 g Hg arc Blue 441.6 1.64067 -- HeCd laser Blue 457.9 1.63718 -- Ar laser Blue 465.8 1.63564 -- Ar laser Blue 472.7 1.63437 -- Ar laser Blue 476.5 1.63370 -- Ar laser Blue 480.0 1.63310 F' Cd arc Blue 486.1 1.63208 F H2 arc Blue 488.0 1.63178 -- Ar laser Blue 496.5 1.63046 -- Ar laser Green 501.7 1.62969 -- Ar laser Green 514.5 1.62790 -- Ar laser Green 532.0 1.62569 -- Nd laser Green 546.1 1.62408 e Hg arc Green 587.6 1.62004 d He arc Yellow 589.3 1.61989 D Na arc Yellow 632.8 1.61656 -- HeNe laser Red 643.8 1.61582 C' Cd arc Red 656.3 1.61503 C H2 arc Red 694.3 1.61288 -- Ruby laser Red 786.0 1.60889 -- -- IR 821.0 1.60768 -- -- IR 830.0 1.60739 -- GaAIAs laser IR 852.1 1.60671 s Ce arc IR 904.0 1.60528 -- GaAS laser IR 1014.0 1.60279 t Hg arc IR 1060.0 1.60190 -- Nd laser IR 1300.0 1.59813 -- InGaAsP laser IR 1500.0 1.59550 -- -- IR 1550.0 1.59487 -- -- IR 1970.1 1.58958 -- Hg arc IR 2325.4 1.58465 -- Hg arc IR

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Optics Guide Copyright 2002 Melles Griot Inc.