Andrea B. Posted February 12, 2015 Share Posted February 12, 2015 Last Update: 06 March 2015 17:30 GMT: Changed title and added a chart. Just a few notes-to-self about glass. Thought I'd go ahead and post them in case you want an approximate transmission range. Newport: http://www.newport.c...33/content.aspx Sinclari: http://www.sinclairm...s/optical3.html Edmund: OPTICAL GLASS SPECIFICATIONS Fused silica: lenses, optics, high temp apps. Silica, SiO2. Hard, very low thermal expansion, resists high temps. Transmits approximately between 195 - 2100nm Soda-lime: windows, containers/glassware Silica + sodium oxide + lime + magnesia. Easily formed, high thermal expansion, poorly resistant to heat. Container glass has more Al/Ca and less Na/Mg. Transmits approximately between 350 - 2000nm Borosilicate: cookware, chemical reagents, mirrors. Silica + boric oxide + soda + alumina. Fairly hard, low thermal expansion, Pyrex. Transmits approx between 380 - 2100nm. (Is this range for borosilicate B7?) From John Dowdy: Borosilicate transmits quite a bit lower than 380nm, 50% transmission can be depending on the thickness and grade. Calcium fluoride: lenses, laser optics. Fluorite, CaF2. Non-birefringent, high thermal expansion, don't use in hot environment. Low index of refraction, anti-reflection coatings not needed. Transmits approximately between 170 - 8000 nm. Magnesium fluoride: lenses, windows, laser polarizers. MgF2. Birefringent, useful in fluorine environments, moderate thermal expansion. Low index of refraction, anti-reflection coatings not needed. Transmits approximately between 150 - 6500 nm. Zinc selenide: thermal imaging, medical IR imaging. ZnSe. Soft, scratchable, resistant to thermal shock. High index of refraction, needs anti-reflection coating. Transmits approximately between 600 - 16000 nm. Sapphire Transmits approximately between 100 280? - 600 nm? Lead-oxide: crystal glassware and decorative ware. Silica + lead oxide + potassium oxide + soda + zinc oxide + alumina. Dense, elastic, high refractive index, cannot stand high heat. Alumino-silicate: fiberglass, in plastics. Silica + alumina + lime + magnesia + barium oxide + boric oxide. Oxide: fiber optics. Silica + germanium oxide. Very clear. From Enrico Savazzi: Germanium (admittedly, not a glass but a metalloid) was used in the past to make IR lenses. Better alternatives are used today, since Germanium is sensitive to surface degradation. It transmits well between 6.5 and 13 micrometers (not nm), but has several narrow transmission windows also at shorter wavelengths. Schott WG Glass: See later posts. Looks good. Here's a nice chart from Edmund Optics: Link to Original Page (More charts in posts below.) Link to comment
JCDowdy Posted February 12, 2015 Share Posted February 12, 2015 Borosilicate transmits quite a bit lower than 380nm, 50% transmission can be <320nm depending on the thickness and grade. see also: OPTICAL GLASS SPECIFICATIONS Link to comment
enricosavazzi Posted February 12, 2015 Share Posted February 12, 2015 Germanium (admittedly, not a glass but a metalloid) was used in the past to make IR lenses. Better alternatives are used today, since Germanium is sensitive to surface degradation. It transmits well between 6.5 and 13 micrometers (not nm), but has several narrow transmission windows also at shorter wavelengths. Link to comment
Andrea B. Posted February 12, 2015 Author Share Posted February 12, 2015 Thanks, gentlemen ! The borosilicate trans chart shown was for B7 I think. I will add a note. And also a note about the Germanium. Twice I've written Geranium !! :P Link to comment
JCDowdy Posted February 12, 2015 Share Posted February 12, 2015 I have a thermoelectrically cooled Germanium detector for an IR spectroradiometer. I also have a Geranium detector with optional cool crumb sweeper. :P Link to comment
Shane Posted February 13, 2015 Share Posted February 13, 2015 Sapphire Transmits approximately between 100 - 600 nm ? Depends on impurity levels and impurity type. Link to comment
rfcurry Posted February 14, 2015 Share Posted February 14, 2015 We also have some good UV transmission with Schott WG225, WG280, etc. which are clear filter glasses. See http://www.schott.co...rt_2013_eng.pdf And the Schott B270 has excellent UV transmission Link to comment
rfcurry Posted February 15, 2015 Share Posted February 15, 2015 I have been using a number of different clear glass types on my new filter. Fused Quartz is available in different transmission capabilities, as is fused silica. Schott sells a fused silica as Lithosil in differing grades. see https://www.thorlabs...ata%20Sheet.pdf Here is a good comparison graphic Below are the curves for GE fused quartz. The GE 124 is a defacto industry standard for optical windows. Link to comment
lost cat Posted December 24, 2015 Share Posted December 24, 2015 How about lanthinum and thorium doped glass? Anyone try those for UV? Link to comment
Shane Posted December 24, 2015 Share Posted December 24, 2015 More than likely they will fluoresce to UV. Link to comment
Alex H Posted December 24, 2015 Share Posted December 24, 2015 Here is a catalog of modern glass from LZOS factory in Russia: http://lzos.ru/content/view/77/29/ And although the list is in Russian language, the leftmost column list current glass type names which themselves are links to spec sheets in English. These spec. sheets, among other things, provide internal transmission for 10mm and 25mm thickness for all glass types. Not all spec. sheets have detailed transmission data for 300-400nm range. Note also that the table lists equivalent (not identical) glass types for Schott (Шотт), Corning (Корнинг Франс), Hoya (Хойя) and Ohara (Охара). Link to comment
lost cat Posted December 24, 2015 Share Posted December 24, 2015 Here is a catalog of modern glass from LZOS factory in Russia: http://lzos.ru/content/view/77/29/ And although the list is in Russian language, the leftmost column list current glass type names which themselves are links to spec sheets in English. These spec. sheets, among other things, provide internal transmission for 10mm and 25mm thickness for all glass types. Not all spec. sheets have detailed transmission data for 300-400nm range. Note also that the table lists equivalent (not identical) glass types for Schott (Шотт), Corning (Корнинг Франс), Hoya (Хойя) and Ohara (Охара). Thank you for the link At the top of the page is an English language button. Here is a link to the same table in English: http://lzos.ru/en/index.php?option=com_content&task=view&id=54 Link to comment
Andrea B. Posted December 24, 2015 Author Share Posted December 24, 2015 Now what is Ohara glass? I think I don't recall hearing about that? Link to comment
lost cat Posted December 24, 2015 Share Posted December 24, 2015 More than likely they will fluoresce to UV. For 10mm sections of glass: KF6 undoped crown has 50% cutoff at ~315nm LK5 fluor doped crown 50% cutoff at ~337nm.LK6 fluor doped crown 50% cutoff at ~325nm.LK7 fluor doped crown 50% cutoff at ~315nm. K8 borosilicate crown 50% cutoff at ~320nm. CTK7 lanthanum doped crown 50% cutoff at ~337nm.CTK9 tantalum doped crown, 50% cutoff at ~355nm.CTK19 tantalum doped crown, 50% cutoff at ~342nm. It appears lanthinum and tantalum doped glass can work but are not as good as other glass types. Of course that would depend on whether the doped lenses can be designed to compensate for the reduced transmission and perhaps may have other benefits to outweigh the drawbacks. Too bad many of the data sheets don't extend into the UV. Link to comment
Shane Posted December 24, 2015 Share Posted December 24, 2015 The glass may still transmit into the UV but that doesn't preclude it from also fluorescing. Link to comment
lost cat Posted December 24, 2015 Share Posted December 24, 2015 The glass may still transmit into the UV but that doesn't preclude it from also fluorescing. Well any photon that makes it to the other side of the glass with the same energy as it entered is a photon not impressed for luminescence. But you are correct, transmission efficiency is but one part of the answer. Quantum yields and wavelengths would be the others. And if the fluorescence is low enough rear mounting a filter might be enough to eliminate it. Link to comment
Shane Posted December 24, 2015 Share Posted December 24, 2015 And if the fluorescence is low enough rear mounting a filter might be enough to eliminate it. Assuming that all fluorescence is occurring in the visible. Link to comment
Alex H Posted December 25, 2015 Share Posted December 25, 2015 Thank you for the link At the top of the page is an English language button. Here is a link to the same table in English: http://lzos.ru/en/in...task=view&id=54 Thanks. I was not paying attention to English language button, since I speak Russian. Unfortunately, these data sheets have limited use. The only publication of lens optical diagrams (from former USSR) that also includes glass types that I was able to find is an old GOI lens catalogue by Lishnevskaya. Link to comment
lost cat Posted December 26, 2015 Share Posted December 26, 2015 Thanks. I was not paying attention to English language button, since I speak Russian. Unfortunately, these data sheets have limited use. The only publication of lens optical diagrams (from former USSR) that also includes glass types that I was able to find is an old GOI lens catalogue by Lishnevskaya. I wouldn't say that exactly. The data shows doped crown glasses don't transmit UV as well as undoped. My next question would be whether lanthinum doped elements might allow for a design that would compensate for the lower UV T. Link to comment
lost cat Posted December 26, 2015 Share Posted December 26, 2015 Assuming that all fluorescence is occurring in the visible. True, any fluorescence in the pass zone of the filter would be problematic. Link to comment
Fandyus Posted August 1, 2023 Share Posted August 1, 2023 Wait a minute, sapphire transmits down to 100nm??? does that mean you could hypothetically make a lens out of it and take pictures at say 110nm inside a vacuum chamber with a naked sensor? That would probably look pretty trippy. I guess everything would look matte and black. Link to comment
dabateman Posted August 1, 2023 Share Posted August 1, 2023 31 minutes ago, Fandyus said: Wait a minute, sapphire transmits down to 100nm??? does that mean you could hypothetically make a lens out of it and take pictures at say 110nm inside a vacuum chamber with a naked sensor? That would probably look pretty trippy. I guess everything would look matte and black. Looks like UV grade sapphire has transmission of 150nm to 6000nm. So not quite that low. But you could definitely image using the 183nm Mercury line. Link to comment
Fandyus Posted August 1, 2023 Share Posted August 1, 2023 Just now, dabateman said: Looks like UV grade sapphire has transmission of 150nm to 6000nm. So not quite that low. But you could definitely image using the 183nm Mercury line. Good to know. Thanks. You've once done something like that, right? Link to comment
dabateman Posted August 1, 2023 Share Posted August 1, 2023 I used a close proximity pinhole lens, as I didn't have anything that could pass the line at the time. I don't have that bulb anymore, either as they are expensive and it blew out before its rated life. Fortunately I was refunded. Link to comment
Fandyus Posted August 1, 2023 Share Posted August 1, 2023 1 minute ago, dabateman said: I used a close proximity pinhole lens, as I didn't have anything that could pass the line at the time. I don't have that bulb anymore, either as they are expensive and it blew out before its rated life. Fortunately I was refunded. Ah, I see. I remember that experiment. Link to comment
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