Optical Filter Glass - Description - 2013
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Optical Filter Glass Description - 2013

SCHOTT is an international technology group with more than 125 years of experience in the areas of specialty glasses and materials and advanced technologies. With our high-quality products and i ­ntelligent solutions, we contribute to our customers’ success and make SCHOTT part of everyone’s life. SCHOTT Advanced Optics, with its deep technological expertise, is a valuable partner for its customers in developing products and customized solutions for applications in optics, lithography, astronomy, opto-electronics, life sciences, and research. With a product portfolio of more than 120...

Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1 Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.2 General information on listed data . . . . . . . . . . . . . . . . . . . 6 1.3 Environmental aspects, hazardous substances, RoHS, ISO, REACh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.4 SCHOTT optical filter glass: ­ roduct portfolio. . . . . . . . . 7 p 4. Thermal and mechanical properties. . . . . . . . . . . . . . . 4.1 Mechanical density ρ [g/cm3]. ....

SCHOTT Advanced Optics offers a wide range of optical filter glasses for any spectral solution to meet individual requirements and enable customized solutions. Optical filter glass is known for its selective absorption in certain wavelength ranges. The optical filter glasses appear to be colored if their filter effect lies within the visible light spectrum. Filters from SCHOTT have been known for their particularly high quality, purity and outstanding properties for more than 100 years. Currently, SCHOTT Advanced Optics’ portfolio comprises more than 58 different optical filter glass types,...

SCHOTT’s optical filter glass portfolio is the product line of choice for system designers and optical engineers and is being constantly updated, reflecting the market needs. While advancing its capabilities, SCHOTT has continuously expanded its optical filter glass portfolio. Thus, now it contains special bandpass filters BG60, BG61 and BG62 as NIR-cut filter for imaging applications. SCHOTT’s optical filters are described in two brochures whereas this brochure named “Description” gives information about the most important criteria that pertain to the materials and characteristics of...

1.2 General information on listed data All data listed in this brochure without tolerances are to be understood as reference values. Only those values listed in chapter 2 of the “Properties” brochure, under “Limit values of τi ,” “Tolerances of NVIS filters,” “Tolerance ranges of τi ,” and “Tolerances for longpass filters” are guaranteed values. The graphically depicted internal transmittance curves serve as an initial overview to assist you in finding the most suitable filter type for your application. Chapter 1 of this “Description” brochure contains an overview of SCHOTT’s optical filter...

1.4 SCHOTT optical filter glass: ­ roduct portfolio p The optical filter glass portfolio of SCHOTT consists of the following filter types in the wavelength range above 200 nm: • Bandpass filters that selectively transmit a desired wavelength range; • Longpass filters that block an undesired shorter wavelength range; • Shortpass filters that block an undesired longer wavelength range; and • Neutral density filters that exhibit nearly constant transmission, especially in the visible range. Filter glass can be used in different thicknesses, which multiply the effects. In addition SCHOTT has a...

2. Nomenclature and classification of optical filter glass Our optical filter glasses are manufactured by using a wide variety of different ingredients and have numerous optical properties. For our portfolio a nomenclature is used that is closely related to the visual appearance of the optical filter glasses and their optical functions. Nevertheless, many other properties are also related to the chemical composition of these glasses and the section ‘classification by material’ describes the three types of chemistry which apply to optical filter glasses. Optical filter glasses are...

The various optical filter glass types can be divided into three classes based on their ­ aterial composition: m Colorless (transparent) optical glass that has the cutoff in a different location in the UV (see N-WG glasses). 2.2.2 Ionically colored glass Ions of heavy metals or rare earths can influence the coloration of glasses in true solution. This coloration depends on the nature and quantity of the coloring substances, the oxidation state of the coloring substances, and the base glass composition (see UG, BG, VG, NG, and KG glasses as well as glass types RG9, RG1000, S8612 and NVIS...

3. Optical properties The following chapter covers the important optical definitions and formulas that are used to describe the optical properties of the optical filter glasses. In addition, the relevant optical features of the optical filter glasses are explained. In imaging optics, light refraction and its spectral dependence (dispersion) are the most important properties; they are determined by the wavelength-dependent refractive index n(λ). However, optical filter glasses are optimized for their characteristic spectral transmission, thus, the refractive indices are basically listed as...

Definition of spectral transmittance: 2 The spectral transmittance τ(λ) in equation 2 which can easily be measured, is the ratio of the transmitted (energetic) spectral flux Θeλ,transmitted to the incident (energetic) spectral flux Θeλ,incident. Hence τ(λ) describes the transmittance of the absorbing optical glass filter considering the reflection losses at the front and rear sides of the filter. Definition of internal spectral transmittance: 3 The spectral internal transmittance τi(λ) in equation 3 is the ratio of the emerging spectral radiant flux Θeλ,leaving to the radiant flux...