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Lab Dichroic

Specification as of 2013_12_11

The substrate must be 1“ in diameter and pass >96% light from 0.5 micron to 2.45 microns. The optical surfaces must be Lambda/8 or better at 632nm, at least 5mm thick. The thickness must be matched to 0.2mm or better. An example substrate would be the Thorlabs Magnesium Fluoride Window WG61050. These substrates could be vendor supplied or supplied by CHARA to the vendor.

Each optic would have a long pass dichroic surface on one side with >50% reflectivity from 0.45 to 0.5 microns, and would pass >96% from 0.55 to 2.45 microns. We also desire as much light as possible between 0.5 and 0.55 microns also pass through the optic. The other side would be anti-reflection coated, ideally for 0.5-2.45 microns but 0.6-2.45 microns is acceptable.

Summary of Results as of 2013_12_11

Cost Per Unit
IR Transmission
CaF2 Substrate
Robert Pursel
Cutoff very close to 0.5um
Includes substrate N-BK7
Get quote for infrasil substrates (done 2013-12-12 no responce)
(infrasil assumed)
Contacted 2014-01-29 concerning CaF2 substrates

Update coating CaF2 substrates we supply
Plus $90 for substrate makes $665s
Closest to our spec.
Cascade Optical

Bit long 550nm
Coating Charge

Contacted 2014-01-29 concerning CaF2 substrates. Response 2014-02-03 $2100 for batch, or the same $350.
Casix Optics
Xanthe Lin
No response yet


No response

ISP Optics
Andrew Houseman
No Curve Given
Substrates Ca-F2

Clarify >50% reflectivity and no rear-surface AR coating.

Updated Quote


Second quote seems to have cleared this up 2013-12-13. Asked 2014-01-29 if they can shorten delivery time. They can 4 wks. Want as much warning as possible and spare substrates.
Stefan Gotz
Substrates FS

Quote needs a rear AR coating added
They say it's because the BW is so high.
Using our substrates will cost $200 more.
(rear AR coating assumed)

omega Filters
Kirk Winchester
No Curve
No broken down.
Corning 7980 - FS
Contacted 2014-01-29 concerning CaF2 substrates. Sent 'Typical' curve in response. States that CaF2 is harder to work with and wants to know why we need it. Quote on the way. Judit confirms that Fused Silica is OK.
Erin Peacox
No Bid

ao/lab_dichroic.txt · Last modified: 2018/07/07 10:16 by jones