On Tuesday, December 8, 2015 at 12:48:39 PM UTC-5, Phil Hobbs wrote:   
   > On 12/07/2015 08:12 PM, ggherold@gmail.com wrote:   
   > > On Monday, December 7, 2015 at 4:18:28 PM UTC-5, Phil Hobbs wrote:   
   > >> Hi, all,   
   > >>   
   > >> Back in the day, Corning used to make sharp-cut red filters with   
   > >> spectacularly low autofluorescence compared with Hoya and Schott ones.   
   > >> H & S seem to light up like a Christmas tree at a wavelength about   
   > >> 50-100 nm to the red of the edge, which is very inconvenient at the   
   moment.   
   > >>   
   > >> Corning doesn't make coloured glass filters any more.   
   > >>   
   > >> Two questions for the assembled multitude:   
   > >>   
   > >> 1. Does anyone know who they sold the line to. if anybody, and if   
   > >> they're still available?   
   > >>   
   > >> 2. Any wisdom on 800-nm-ish sharp cut longpass filters with super low   
   > >> autofluorescence?   
   > >>   
   > >> Thanks   
   > >>   
   > >> Phil Hobbs   
   >   
   > > How much money, how many, size?   
   > > (my first hit on Thor labs was a $73   
   > > 1" (?) piece, )   
   > > I get big interference filters from Custom Scientific, AZ,   
   > > for less than that, (per area.)   
   > > (I only mention them selfishly, 'cause I want   
   > > them to be around ~5 years from now, depending on sales.)   
   > >   
   > > If you want just absorbing glass,   
   > > (like for an argon laser into a spectrometer)   
   > > what's the intensity? (maybe china?, I dunno)   
   > > At the very low end,   
   > > I've got plastic filter samples for lighting,   
   > > Lee filters, with transmission vs wavelength plots.   
   > >   
   > > George H.   
   > >   
   >   
   > Needs to be super cheap.  So cheap that we're looking at choosing   
   > fluorophores and pump sources so that we can use just the IR-filtered   
   > photodiode to get rid of the pump light.   
   >   
   > Black glass or more IR-absorbing plastic would be fine if it doesn't   
   > fluoresce much.   
   >   
   > Cheers   
   >   
   > Phil Hobbs   
   >   
   > --   
   > Dr Philip C D Hobbs   
   > Principal Consultant   
   > ElectroOptical Innovations LLC   
   > Optics, Electro-optics, Photonics, Analog Electronics   
   >   
   > 160 North State Road #203   
   > Briarcliff Manor NY 10510   
   >   
   > hobbs at electrooptical dot net   
   > http://electrooptical.net   
      
   Do you have a way to quickly check for fluorescence?   
   If so you might order sample pieces of all the black poly/ plastic   
   sheet in McMaster-Carr.  (There are certainly black plastics   
   that transmit at ~800 nm.)   
   (or search online maybe someone has done the measurement...?)   
      
   http://www.eplastics.com/Plexiglass_Acrylic_Sheet_Infrared_Transmitting   
      
      
   Ask for a sample?   
      
   George H.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)