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ao:dichroic_specification [2018/07/06 13:37]
127.0.0.1 external edit
ao:dichroic_specification [2018/07/07 09:22] (current)
jones [Finished beam splitter transmission/reflection curves received from vendor Uploaded 2013-10-31]
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 +====== Dichroic Specification ======
 ===== Note and Files ===== ===== Note and Files =====
-\\  Some notes and files concerning the specification of the Dichroic.\\ \\ [[file/view/11%20ISO%2010110.pdf/299812588/11%20ISO%2010110.pdf|11 ISO 10110.pdf]] - Some old slides from Steve concerning ISO 10110.\\ \\ [[file/view/Finishing%20specs.pdf/299812596/Finishing%20specs.pdf|Finishing specs.pdf]] - Dichroic Specification from Judit as of Feb 6th 2012.\\ \\ [[file/view/Window-thickness-refractive-index.xlsx/299812598/Window-thickness-refractive-index.xlsx|Window-thickness-refractive-index.xlsx]] - Spread sheet from Steve showing how he calculated the thickness criteria.\\ \\ [[file/view/BSpl%20specs%20V2.pdf/300171486/BSpl%20specs%20V2.pdf|BSpl specs V2.pdf]] - Version two of specification as of Feb 8th 2012\\ \\ [[file/view/EscoQuote_14338.pdf/300171366/EscoQuote_14338.pdf|EscoQuote_14338.pdf]] - First quote from ESCO Feb 07 2012\\ \\ [[/file/view/EscoQuote_14806.pdf/365494804/EscoQuote_14806.pdf|EscoQuote_14806.pdf]] - This is the final quote (4/19/2012) used to order the substrates.\\ \\ [[/file/view/IntenProfile_vs_bluecutoff.mov/370014054/IntenProfile_vs_bluecutoff.mov|IntenProfile_vs_bluecutoff.mov]] - Total intensity profile as a function of blue cutoff wavelength of dichroic\\ \\ [[/file/view/bluecutoffslides.pdf/370014114/bluecutoffslides.pdf|bluecutoffslides.pdf ]]- study of optimal blue cutoff wavelength of dichroic\\ +\\  Some notes and files concerning the specification of the Dichroic.\\ \\ {{ao:11_ISO_10110.pdf|11 ISO 10110.pdf}} - Some old slides from Steve concerning ISO 10110.\\ \\ {{ao:Finishing_specs.pdf|Finishing specs.pdf}} - Dichroic Specification from Judit as of Feb 6th 2012.\\ \\ {{ao:Window-thickness-refractive-index.xlsx|Window-thickness-refractive-index.xlsx}} - Spread sheet from Steve showing how he calculated the thickness criteria.\\ \\ {{ao:BSpl_specs_V2.pdf|BSpl specs V2.pdf}} - Version two of specification as of Feb 8th 2012\\ \\ {{ao:EscoQuote_14338.pdf|EscoQuote_14338.pdf}} - First quote from ESCO Feb 07 2012\\ \\ {{ao:EscoQuote_14806.pdf|EscoQuote_14806.pdf}} - This is the final quote (4/19/2012) used to order the substrates.\\ \\ [[http://chara.gsu.edu/wiki/data/pages/ao/files/IntenProfile_vs_bluecutoff.mov|IntenProfile_vs_bluecutoff.mov]] - Total intensity profile as a function of blue cutoff wavelength of dichroic\\ \\ {{ao:bluecutoffslides.pdf|bluecutoffslides.pdf }}- study of optimal blue cutoff wavelength of dichroic\\ 
 ===== IR Dichroic Short-Wave Cutoff ===== ===== IR Dichroic Short-Wave Cutoff =====
 \\  There appears to be some consensus that highly reddened objects are important fot he IR dichroic, so the long-wave cutoff should be 1 micron or so. The short-wave cutoff is controversial. The key drivers for cutoff are:\\  \\  There appears to be some consensus that highly reddened objects are important fot he IR dichroic, so the long-wave cutoff should be 1 micron or so. The short-wave cutoff is controversial. The key drivers for cutoff are:\\ 
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 | Image shift (60 degrees from zenith, arcsec)\\ | 1.64\\ | 0.87\\ | 0.44\\ | 0.18\\ | 0\\ | | Image shift (60 degrees from zenith, arcsec)\\ | 1.64\\ | 0.87\\ | 0.44\\ | 0.18\\ | 0\\ |
  These two tables, taken together, imply that for a 500nm dichroic short-wave cutoff (with respect to a 400nm cutoff), there would be a 0.06 mag sensitivity loss at zenith, and a sensitivity gain at higher airmasses. A 600nm dichroic short-wave cutoff (with respect to a 500nm cutoff) loses an additional 0.12 mags sensitivity at zenith and doesn't cause a sensitivity gain until high airmass.\\ \\  On the basis of this study MJI suggests specifying a dichroic with a reflection band of 0.55 to 1.0 microns, and a transmission band of 1.15 to 2.4 microns. State that we intend to use some of the transmitted light short-wards of 0.55 microns, and would like to know the predicted curve down to 0.4 microns.\\ \\ \\ \\   These two tables, taken together, imply that for a 500nm dichroic short-wave cutoff (with respect to a 400nm cutoff), there would be a 0.06 mag sensitivity loss at zenith, and a sensitivity gain at higher airmasses. A 600nm dichroic short-wave cutoff (with respect to a 500nm cutoff) loses an additional 0.12 mags sensitivity at zenith and doesn't cause a sensitivity gain until high airmass.\\ \\  On the basis of this study MJI suggests specifying a dichroic with a reflection band of 0.55 to 1.0 microns, and a transmission band of 1.15 to 2.4 microns. State that we intend to use some of the transmitted light short-wards of 0.55 microns, and would like to know the predicted curve down to 0.4 microns.\\ \\ \\ \\ 
-===== **Coating specifications** =====+===== Coating specifications =====
 \\ We agreed to send the following coating specifications to vendors in October, 2012\\  There will be two sets of beam splitters, YSO and VIS, on IR grade low-OH fused silica substrates. \\  The requirements for the coatings are as follows:\\ \\ __YSO dichroic – 6 pieces:__\\  AOI 10 degrees\\  Non polarizing\\  Surface 1: In the spectral range of 600 to 1000 nm it should reflect as much as possible, and in the range of 1100 to 2400 nm transmit as much as possible.\\  Surface 2: Antireflection coating for 1100 to 2400 nm\\ We would also like to know the predicted curve down to 400 nm.\\ \\ __VIS dichroics – 6 pieces:__\\  AOI 10 degrees\\  Non polarizing\\  Surface 1: In the spectral range of 600 to 1000 nm a gray split: R~20% T~80%,\\  in the 1100 to 2400 nm range it should transmit as much as possible.\\  Surface 2: Antireflection coating for 1100 to 2400 nm\\ We would also like to know the predicted curve down to 400 nm.\\ \\  \\ We agreed to send the following coating specifications to vendors in October, 2012\\  There will be two sets of beam splitters, YSO and VIS, on IR grade low-OH fused silica substrates. \\  The requirements for the coatings are as follows:\\ \\ __YSO dichroic – 6 pieces:__\\  AOI 10 degrees\\  Non polarizing\\  Surface 1: In the spectral range of 600 to 1000 nm it should reflect as much as possible, and in the range of 1100 to 2400 nm transmit as much as possible.\\  Surface 2: Antireflection coating for 1100 to 2400 nm\\ We would also like to know the predicted curve down to 400 nm.\\ \\ __VIS dichroics – 6 pieces:__\\  AOI 10 degrees\\  Non polarizing\\  Surface 1: In the spectral range of 600 to 1000 nm a gray split: R~20% T~80%,\\  in the 1100 to 2400 nm range it should transmit as much as possible.\\  Surface 2: Antireflection coating for 1100 to 2400 nm\\ We would also like to know the predicted curve down to 400 nm.\\ \\ 
 ==== Finished beam splitter transmission/reflection curves received from vendor Uploaded 2013-10-31 ==== ==== Finished beam splitter transmission/reflection curves received from vendor Uploaded 2013-10-31 ====
-[[/file/view/AO-VISsplitter.PDF/464996256/AO-VISsplitter.PDF|{{http://www.wikispaces.com/i/mime/32/application/pdf.png?32x32|AO-VISsplitter.PDF}}]][[/file/view/AO-VISsplitter.PDF/464996256/AO-VISsplitter.PDF|AO-VISsplitter.PDF]]\\ +{{ao:AO-VISsplitter.PDF|AO-VISsplitter.PDF}}\\  
 +{{ao:AO-YSOsplitter.PDF|AO-YSOsplitter.PDF}}\\ 
  
-  * [[/file/detail/AO-VISsplitter.PDF|Details]] 
-  * [[/file/view/AO-VISsplitter.PDF/464996256/AO-VISsplitter.PDF|Download]] 
-  * 69 KB 
-\\ [[/file/view/AO-YSOsplitter.PDF/464996230/AO-YSOsplitter.PDF|{{http://www.wikispaces.com/i/mime/32/application/pdf.png?32x32|AO-YSOsplitter.PDF}}]][[/file/view/AO-YSOsplitter.PDF/464996230/AO-YSOsplitter.PDF|AO-YSOsplitter.PDF]]\\  
- 
-  * [[/file/detail/AO-YSOsplitter.PDF|Details]] 
-  * [[/file/view/AO-YSOsplitter.PDF/464996230/AO-YSOsplitter.PDF|Download]] 
-  * 70 KB 
ao/dichroic_specification.1530898653.txt.gz · Last modified: 2018/07/06 13:37 by 127.0.0.1