CaF 2 windows are also commonly used in cryogenically cooled thermal imaging systems. Choose professional Dilatometry and Thermal Expansion Coefficient (CTE) Testing Services from MSE Analytical Services. Since the B and C coefficients are relatively Additionally, a common concern with IR applications is their tendency to produce a large amount of heat. 1,1,2-Trichloroethane is a colorless, sweet-smelling liquid. Fused Silica is an entirely synthetic material, and is technically the purest glass. Silica Refractories are containing more than 93% SiO2 and characterized by a high coefficient of thermal expansion between room temperature and 500C. I would like to know how large the coefficient of thermal expansion of the cavity is and how large the long-term drift of the cavity is when it is drove by SA201 with 1x sweep expansion. Manufacture. Fused quartz (transparent) and fused silica (transparent) are amorphous products resulting from high temperature treatment. 1,1,2-Trichloroethane is a colorless, sweet-smelling liquid. Its coefficient is 1/34 that of copper and only 1/7 of borosilicate glass. Optical systems have to be optimized for a total set of functional characteristics. The radian is defined in the SI as being a dimensionless unit with 1 rad = 1. Silicon Dioxide Glass Quartz Fused Silica Silicon Dioxide (SiO 2) is the most simple chemical composition of glass. CTE is the rate at which a material expands or contracts given a change in temperature. A frit is a ceramic composition that has been fused, quenched, and granulated.Frits form an important part of the batches used in compounding enamels and ceramic glazes; the purpose of this pre-fusion is to render any soluble and/or toxic components insoluble by causing them to combine with silica and other added oxides. The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). Here is the resistance at temperature T, is the resistance at 0 C, and the constants (for an = 0.00385 platinum RTD) are: = , = , = . Given its low absorption coefficient and high damage threshold, uncoated calcium fluoride crystal is a popular choice for use with excimer lasers. Fused Silica Bricks & Blocks. What is the Thermal Expansion coefficient of the Fused Silica Optic Mirror? Thermal expansion is the tendency of matter to change its shape, area, volume, and density in response to a change in temperature, usually not including phase transitions.. Custom Fused Quartz. One of the most important properties of fused quartz is its extremely low coefficient of thermal expansion: 5.5 x 10 7 /C (20320C). REFERENCES: (1) Handbook Optical Constants, ed Palik, V1, ISBN 0-12-544420-6 Thermal expansion is the tendency of matter to change its shape, area, volume, and density in response to a change in temperature, usually not including phase transitions.. Quartz Technology. Geometrical and color-induced aberrations can be compensated only by the use of more than one glass type. The rod is usually suspended from the clock frame with a short straight The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). Silica (fused) 80 to 0C: 0.22: Silica (fused) 0 to 100C: 0.50: For low V r, the transverse expansion coefficient of the composite can thus be significantly larger than As an example, Fig. The rod is usually suspended from the clock frame with a short straight Geometrical and color-induced aberrations can be compensated only by the use of more than one glass type. A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions.Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion.Heat from nuclear fission is passed to a working fluid (water or gas), which in turn runs through steam turbines.These either drive a ship's propellers Silica Refractories are containing more than 93% SiO2 and characterized by a high coefficient of thermal expansion between room temperature and 500C. Choose professional Dilatometry and Thermal Expansion Coefficient (CTE) Testing Services from MSE Analytical Services. Manufacture. Laboratory glassware may be made from several types of glass, each with different capabilities and used for different purposes. The type known as a thermionic tube or thermionic valve utilizes thermionic emission of electrons from a hot cathode for fundamental electronic functions such Fused Silica is tough and hard and has a very low expansion. Laboratory glassware may be made from several types of glass, each with different capabilities and used for different purposes. Triplet-fusion-based photon upconversion is promising for photovoltaic or bioimaging applications, but its efficiency is limited by triplet fusion spin dependence. Thermal expansion refers to the oxide's volume expansion or shrinkage, when exposed to a range of temperatures. However, not all glass that is fused and quenched Its symbol is accordingly often The pendulum in most clocks (see diagram) consists of a wood or metal rod (a) with a metal weight called the bob (b) on the end. A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied.. Figure 2: EO Abbe diagram with Coefficient of Thermal Expansion and Relative Partial Dispersion. Triplet-fusion-based photon upconversion is promising for photovoltaic or bioimaging applications, but its efficiency is limited by triplet fusion spin dependence. Fused quartz is a glass made from chemically-pure silica. 1,1,2-Trichloroethane is sometimes present as an impurity in other chemicals, and it may be Broadly speaking, there are two categories of measurement techniques: steady-state and transient.Steady-state techniques infer the thermal conductivity from measurements on the state of a material once a steady-state temperature profile has been reached, whereas It has very low thermal expansion and excellent resistance to thermal shock , being able to survive immersion in water while red hot, resists high temperatures (10001500 C) and chemical weathering, and is very hard. A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied.. A frit is a ceramic composition that has been fused, quenched, and granulated.Frits form an important part of the batches used in compounding enamels and ceramic glazes; the purpose of this pre-fusion is to render any soluble and/or toxic components insoluble by causing them to combine with silica and other added oxides. CaF 2 windows are also commonly used in cryogenically cooled thermal imaging systems. It has very low thermal expansion and excellent resistance to thermal shock , being able to survive immersion in water while red hot, resists high temperatures (10001500 C) and chemical weathering, and is very hard. Fused quartz, fused silica or quartz glass is a glass consisting of almost pure silica (silicon dioxide, SiO 2) (then more often referred to as fused silica) in the ultraviolet. Learn More. A frit is a ceramic composition that has been fused, quenched, and granulated.Frits form an important part of the batches used in compounding enamels and ceramic glazes; the purpose of this pre-fusion is to render any soluble and/or toxic components insoluble by causing them to combine with silica and other added oxides. The halogens (/ h l d n, h e-,-l o-,- d n /) are a group in the periodic table consisting of five or six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). Optical systems have to be optimized for a total set of functional characteristics. Choose a UV Fused Silica Right-Angle Prism if your application would benefit from higher transmission in the UV or a lower coefficient of thermal expansion. Fused Silica is an entirely synthetic material, and is technically the purest glass. Fused Silica is an entirely synthetic material, and is technically the purest glass. Resistance-thermometer elements functioning up to 1000 C can be supplied. Custom Fused Quartz. Borosilicate (low expansion, similar to Pyrex, Duran) Glass wool (for thermal insulation) Special optical glass (similar to Lead crystal) Fused silica Germania glass Germanium selenide glass Chemical composition, wt% 74 SiO 2, 13 Na 2 O, 10.5 CaO, 1.3 Al 2 O 3, 0.3 K 2 O, 0.2 SO 3, 0.2 MgO, 0.01 TiO 2, 0.04 Fe 2 O 3 Silica compositions can be applied for hot patching, shrouds and bricks. Normal varieties of Fused Silica contain water which gives strong absortion in the IR. The relation between temperature and resistance is given by the Callendar-Van Dusen equation: = [+ + + ()] (< <), = [+ +] (<). The pendulum in most clocks (see diagram) consists of a wood or metal rod (a) with a metal weight called the bob (b) on the end. Wooden rods were often used in quality clocks because wood had a lower coefficient of thermal expansion than metal. Estimated Permeability Constants Through Fused Silica at 700C. Password requirements: 6 to 30 characters long; ASCII characters only (characters found on a standard US keyboard); must contain at least 4 different symbols; Together with hydrogen they constitute group 1, which lies in the s-block of the periodic table.All alkali metals have their outermost electron in an s-orbital: this shared electron configuration results in their having very similar characteristic Estimated Permeability Constants Through Fused Silica at 700C. Given its low absorption coefficient and high damage threshold, uncoated calcium fluoride crystal is a popular choice for use with excimer lasers. The radian, denoted by the symbol rad, is the unit of angle in the International System of Units (SI), and is the standard unit of angular measure used in many areas of mathematics.The unit was formerly an SI supplementary unit (before that category was abolished in 1995). Estimated Permeability Constants Through Fused Silica at 700C. Figure 2: EO Abbe diagram with Coefficient of Thermal Expansion and Relative Partial Dispersion. The artificially created element 117, tennessine (Ts), may also be a halogen. Learn More. The low coefficient of thermal expansion of fused quartz makes it a useful material for precision mirror substrates. Resistance-thermometer elements functioning up to 1000 C can be supplied. There are several ways to measure thermal conductivity; each is suitable for a limited range of materials. Fused quartz (transparent) and fused silica (transparent) are amorphous products resulting from high temperature treatment. YLohia (posted 2018-06-11 05:54:01.0) Hello, the coefficient of thermal expansion for UVFS is 0.55 x 10^-6 /C. When a substance is heated, molecules begin to vibrate and move more, usually creating more distance between There are several ways to measure thermal conductivity; each is suitable for a limited range of materials. One of the most important properties of fused quartz is its extremely low coefficient of thermal expansion: 5.5 x 10 7 /C (20320C). Aluminium oxynitride (marketed under the name ALON by Surmet Corporation) is a transparent ceramic composed of aluminium, oxygen and nitrogen.ALON is optically transparent ( 80%) in the near-ultraviolet, visible, and midwave-infrared regions of the electromagnetic spectrum. I would like to know how large the coefficient of thermal expansion of the cavity is and how large the long-term drift of the cavity is when it is drove by SA201 with 1x sweep expansion. Triplet-fusion-based photon upconversion is promising for photovoltaic or bioimaging applications, but its efficiency is limited by triplet fusion spin dependence. Custom Fused Quartz. A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions.Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion.Heat from nuclear fission is passed to a working fluid (water or gas), which in turn runs through steam turbines.These either drive a ship's propellers Password requirements: 6 to 30 characters long; ASCII characters only (characters found on a standard US keyboard); must contain at least 4 different symbols; Together with hydrogen they constitute group 1, which lies in the s-block of the periodic table.All alkali metals have their outermost electron in an s-orbital: this shared electron configuration results in their having very similar characteristic Thermal expansion refers to the oxide's volume expansion or shrinkage, when exposed to a range of temperatures. Broadly speaking, there are two categories of measurement techniques: steady-state and transient.Steady-state techniques infer the thermal conductivity from measurements on the state of a material once a steady-state temperature profile has been reached, whereas CaF 2 windows are also commonly used in cryogenically cooled thermal imaging systems. Fused Silica is tough and hard and has a very low expansion. Fused quartz, fused silica or quartz glass is a glass consisting of almost pure silica (silicon dioxide, SiO 2) (then more often referred to as fused silica) in the ultraviolet. 1,1,2-Trichloroethane is sometimes present as an impurity in other chemicals, and it may be Silica compositions can be applied for hot patching, shrouds and bricks. Borosilicate glass is a type of transparent glass that is composed of boron oxide and silica, its main feature is a low coefficient of thermal expansion making it more resistant to thermal shock than most other glasses. The low coefficient of thermal expansion of fused quartz makes it a useful material for precision mirror substrates. Aluminium oxynitride (marketed under the name ALON by Surmet Corporation) is a transparent ceramic composed of aluminium, oxygen and nitrogen.ALON is optically transparent ( 80%) in the near-ultraviolet, visible, and midwave-infrared regions of the electromagnetic spectrum. When a substance is heated, molecules begin to vibrate and move more, usually creating more distance between Here is the resistance at temperature T, is the resistance at 0 C, and the constants (for an = 0.00385 platinum RTD) are: = , = , = . Fused quartz (transparent) and fused silica (transparent) are amorphous products resulting from high temperature treatment. I would like to know how large the coefficient of thermal expansion of the cavity is and how large the long-term drift of the cavity is when it is drove by SA201 with 1x sweep expansion. Choose professional Dilatometry and Thermal Expansion Coefficient (CTE) Testing Services from MSE Analytical Services. Together with hydrogen they constitute group 1, which lies in the s-block of the periodic table.All alkali metals have their outermost electron in an s-orbital: this shared electron configuration results in their having very similar characteristic A material's index gradient and coefficient of thermal expansion (CTE) should be evaluated to ensure the user is met with the desired performance. Here is the resistance at temperature T, is the resistance at 0 C, and the constants (for an = 0.00385 platinum RTD) are: = , = , = . REFERENCES: (1) Handbook Optical Constants, ed Palik, V1, ISBN 0-12-544420-6 It has the highest temperature characteristics of any glass, and it often begins as pure silicon gas. The halogens (/ h l d n, h e-,-l o-,- d n /) are a group in the periodic table consisting of five or six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). 1,1,2-Trichloroethane is sometimes present as an impurity in other chemicals, and it may be Quartz is the most stable crystal modification at normal temperature and pressure conditions. However, not all glass that is fused and quenched It is four times as hard as fused silica glass, 85% as hard as sapphire, and nearly 115% as hard as Its coefficient is 1/34 that of copper and only 1/7 of borosilicate glass. Fused Silica is tough and hard and has a very low expansion. A material's index gradient and coefficient of thermal expansion (CTE) should be evaluated to ensure the user is met with the desired performance. Since the B and C coefficients are relatively Since the B and C coefficients are relatively Resistance-thermometer elements functioning up to 1000 C can be supplied. The artificially created element 117, tennessine (Ts), may also be a halogen. Silica (fused) 80 to 0C: 0.22: Silica (fused) 0 to 100C: 0.50: For low V r, the transverse expansion coefficient of the composite can thus be significantly larger than As an example, Fig. It has the highest temperature characteristics of any glass, and it often begins as pure silicon gas. Temperature is a monotonic function of the average molecular kinetic energy of a substance. One of the most attractive features of quartz glass is its very low thermal coefficient of expansion (CTE). Fused quartz, fused silica or quartz glass is a glass consisting of almost pure silica (silicon dioxide, SiO 2) (then more often referred to as fused silica) in the ultraviolet. YLohia (posted 2018-06-11 05:54:01.0) Hello, the coefficient of thermal expansion for UVFS is 0.55 x 10^-6 /C. One of the most attractive features of quartz glass is its very low thermal coefficient of expansion (CTE). The radian is defined in the SI as being a dimensionless unit with 1 rad = 1. A material's index gradient and coefficient of thermal expansion (CTE) should be evaluated to ensure the user is met with the desired performance. The bob is traditionally lens-shaped to reduce air drag. Additionally, a common concern with IR applications is their tendency to produce a large amount of heat. 1,1,2-Trichloroethane is a colorless, sweet-smelling liquid. Fused quartz and silica have an extremely low coefficient of thermal expansion which imparts a high resistance to thermal shock. Silicon Dioxide Glass Quartz Fused Silica Silicon Dioxide (SiO 2) is the most simple chemical composition of glass. Its symbol is accordingly often Quartz is the most stable crystal modification at normal temperature and pressure conditions. Broadly speaking, there are two categories of measurement techniques: steady-state and transient.Steady-state techniques infer the thermal conductivity from measurements on the state of a material once a steady-state temperature profile has been reached, whereas When a substance is heated, molecules begin to vibrate and move more, usually creating more distance between Silicon Dioxide Glass Quartz Fused Silica Silicon Dioxide (SiO 2) is the most simple chemical composition of glass. Its symbol is accordingly often Choose a UV Fused Silica Right-Angle Prism if your application would benefit from higher transmission in the UV or a lower coefficient of thermal expansion. Fused Silica. Borosilicate glass is a type of transparent glass that is composed of boron oxide and silica, its main feature is a low coefficient of thermal expansion making it more resistant to thermal shock than most other glasses. It does not burn easily, can be dissolved in water, and evaporates easily.It is used as a solvent (a chemical that dissolves other substances) and as an intermediate in the production of the chemical, 1,1-dichloroethane. One of the most attractive features of quartz glass is its very low thermal coefficient of expansion (CTE). Borosilicate (low expansion, similar to Pyrex, Duran) Glass wool (for thermal insulation) Special optical glass (similar to Lead crystal) Fused silica Germania glass Germanium selenide glass Chemical composition, wt% 74 SiO 2, 13 Na 2 O, 10.5 CaO, 1.3 Al 2 O 3, 0.3 K 2 O, 0.2 SO 3, 0.2 MgO, 0.01 TiO 2, 0.04 Fe 2 O 3 Water-free varieties of Fused Silica are available. Quartz Technology. Temperature is a monotonic function of the average molecular kinetic energy of a substance. Optical systems have to be optimized for a total set of functional characteristics. The rod is usually suspended from the clock frame with a short straight Quartz Technology. In the modern IUPAC nomenclature, this group is known as group 17. Fused Silica is the glassy form of Quartz and is thus isotropic. Water-free varieties of Fused Silica are available. It does not burn easily, can be dissolved in water, and evaporates easily.It is used as a solvent (a chemical that dissolves other substances) and as an intermediate in the production of the chemical, 1,1-dichloroethane. A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions.Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion.Heat from nuclear fission is passed to a working fluid (water or gas), which in turn runs through steam turbines.These either drive a ship's propellers Silica Refractories are containing more than 93% SiO2 and characterized by a high coefficient of thermal expansion between room temperature and 500C. Fused quartz is a glass made from chemically-pure silica. Fused quartz and silica have an extremely low coefficient of thermal expansion which imparts a high resistance to thermal shock. Fused Silica is the glassy form of Quartz and is thus isotropic. YLohia (posted 2018-06-11 05:54:01.0) Hello, the coefficient of thermal expansion for UVFS is 0.55 x 10^-6 /C. The halogens (/ h l d n, h e-,-l o-,- d n /) are a group in the periodic table consisting of five or six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). For oxides, the thermal expansion coefficient is very low, meaning it does not exert much stress and strain on other materials which are in contact with it. Given its low absorption coefficient and high damage threshold, uncoated calcium fluoride crystal is a popular choice for use with excimer lasers. REFERENCES: (1) Handbook Optical Constants, ed Palik, V1, ISBN 0-12-544420-6 However, not all glass that is fused and quenched Fused Silica Bricks & Blocks. Wooden rods were often used in quality clocks because wood had a lower coefficient of thermal expansion than metal. The bob is traditionally lens-shaped to reduce air drag. Normal varieties of Fused Silica contain water which gives strong absortion in the IR. Fused quartz and silica have an extremely low coefficient of thermal expansion which imparts a high resistance to thermal shock. The type known as a thermionic tube or thermionic valve utilizes thermionic emission of electrons from a hot cathode for fundamental electronic functions such Quartz is the most stable crystal modification at normal temperature and pressure conditions. Normal varieties of Fused Silica contain water which gives strong absortion in the IR. Silica compositions can be applied for hot patching, shrouds and bricks. What is the Thermal Expansion coefficient of the Fused Silica Optic Mirror? Thermal expansion refers to the oxide's volume expansion or shrinkage, when exposed to a range of temperatures. Figure 2: EO Abbe diagram with Coefficient of Thermal Expansion and Relative Partial Dispersion. In the modern IUPAC nomenclature, this group is known as group 17. Fused quartz is a glass made from chemically-pure silica. Borosilicate glass is a type of transparent glass that is composed of boron oxide and silica, its main feature is a low coefficient of thermal expansion making it more resistant to thermal shock than most other glasses. The type known as a thermionic tube or thermionic valve utilizes thermionic emission of electrons from a hot cathode for fundamental electronic functions such The artificially created element 117, tennessine (Ts), may also be a halogen. It is four times as hard as fused silica glass, 85% as hard as sapphire, and nearly 115% as hard as Manufacture. The radian, denoted by the symbol rad, is the unit of angle in the International System of Units (SI), and is the standard unit of angular measure used in many areas of mathematics.The unit was formerly an SI supplementary unit (before that category was abolished in 1995). Password requirements: 6 to 30 characters long; ASCII characters only (characters found on a standard US keyboard); must contain at least 4 different symbols; Fused Silica. In the modern IUPAC nomenclature, this group is known as group 17. Learn More. The pendulum in most clocks (see diagram) consists of a wood or metal rod (a) with a metal weight called the bob (b) on the end. Its coefficient is 1/34 that of copper and only 1/7 of borosilicate glass. Water-free varieties of Fused Silica are available. What is the Thermal Expansion coefficient of the Fused Silica Optic Mirror? The radian is defined in the SI as being a dimensionless unit with 1 rad = 1. CTE is the rate at which a material expands or contracts given a change in temperature. Wooden rods were often used in quality clocks because wood had a lower coefficient of thermal expansion than metal. Fused Silica Bricks & Blocks. CTE is the rate at which a material expands or contracts given a change in temperature. The relation between temperature and resistance is given by the Callendar-Van Dusen equation: = [+ + + ()] (< <), = [+ +] (<). Silica (fused) 80 to 0C: 0.22: Silica (fused) 0 to 100C: 0.50: For low V r, the transverse expansion coefficient of the composite can thus be significantly larger than As an example, Fig. Aluminium oxynitride (marketed under the name ALON by Surmet Corporation) is a transparent ceramic composed of aluminium, oxygen and nitrogen.ALON is optically transparent ( 80%) in the near-ultraviolet, visible, and midwave-infrared regions of the electromagnetic spectrum. A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied.. It has very low thermal expansion and excellent resistance to thermal shock , being able to survive immersion in water while red hot, resists high temperatures (10001500 C) and chemical weathering, and is very hard. The bob is traditionally lens-shaped to reduce air drag. It is four times as hard as fused silica glass, 85% as hard as sapphire, and nearly 115% as hard as The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). One of the most important properties of fused quartz is its extremely low coefficient of thermal expansion: 5.5 x 10 7 /C (20320C). For oxides, the thermal expansion coefficient is very low, meaning it does not exert much stress and strain on other materials which are in contact with it. Additionally, a common concern with IR applications is their tendency to produce a large amount of heat. Laboratory glassware may be made from several types of glass, each with different capabilities and used for different purposes. The radian, denoted by the symbol rad, is the unit of angle in the International System of Units (SI), and is the standard unit of angular measure used in many areas of mathematics.The unit was formerly an SI supplementary unit (before that category was abolished in 1995). Fused Silica. The low coefficient of thermal expansion of fused quartz makes it a useful material for precision mirror substrates. Borosilicate (low expansion, similar to Pyrex, Duran) Glass wool (for thermal insulation) Special optical glass (similar to Lead crystal) Fused silica Germania glass Germanium selenide glass Chemical composition, wt% 74 SiO 2, 13 Na 2 O, 10.5 CaO, 1.3 Al 2 O 3, 0.3 K 2 O, 0.2 SO 3, 0.2 MgO, 0.01 TiO 2, 0.04 Fe 2 O 3 Thermal expansion is the tendency of matter to change its shape, area, volume, and density in response to a change in temperature, usually not including phase transitions.. Geometrical and color-induced aberrations can be compensated only by the use of more than one glass type. There are several ways to measure thermal conductivity; each is suitable for a limited range of materials. For oxides, the thermal expansion coefficient is very low, meaning it does not exert much stress and strain on other materials which are in contact with it. Fused Silica is the glassy form of Quartz and is thus isotropic. The relation between temperature and resistance is given by the Callendar-Van Dusen equation: = [+ + + ()] (< <), = [+ +] (<). It has the highest temperature characteristics of any glass, and it often begins as pure silicon gas. It does not burn easily, can be dissolved in water, and evaporates easily.It is used as a solvent (a chemical that dissolves other substances) and as an intermediate in the production of the chemical, 1,1-dichloroethane. Temperature is a monotonic function of the average molecular kinetic energy of a substance. Choose a UV Fused Silica Right-Angle Prism if your application would benefit from higher transmission in the UV or a lower coefficient of thermal expansion.