Corning filter glass

Post by Phil Hobbs
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.
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
--
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

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.

Phil Hobbs

2015-12-08 17:48:37 UTC

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

g***@gmail.com

2015-12-08 21:13:05 UTC

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.

Well I never knew the glass would fluoresce. (so I learned something)
Not useful, But I once purchased photodiodes with a vis. blocking filter on the
face. (Darn things were polarization sensitive.) Photonic detectors..
I think here now...
http://advancedphotonix.com/optosolutions/products/photodiodes-arrays-optoelectronic-modules/
Not the ones I bought which were in a metal can package.

George H.

Post by Phil Hobbs
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

Phil Hobbs

2015-12-09 15:58:27 UTC

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.

Depending on exactly where the fluorophore emits, I may use a SFH2400FP,
which has visible-blocking plastic on it.

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

g***@gmail.com

2015-12-08 23:33:26 UTC

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.

Phil Hobbs

2015-12-09 16:09:26 UTC

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.

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?

The simple way is just to aim a DVD laser at it and see what makes it
through off axis. Generally fluorescence is more or less isotropic.

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

Helpful person

2015-12-08 13:22:23 UTC

That's interesting. I would expect all the manufacturers to use the same dyes, especially "back in the day". Do you have any theories as why the Schott and Ohara filters fluoresce? Seems very odd, and of course very annoying.

http://www.richardfisher.com

Phil Hobbs

2015-12-08 17:14:18 UTC

Post by Helpful person

Post by Phil Hobbs
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.
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

That's interesting. I would expect all the manufacturers to use the
same dyes, especially "back in the day". Do you have any theories as
why the Schott and Ohara filters fluoresce? Seems very odd, and of
course very annoying.
http://www.richardfisher.com

I think the glass filters are colour centres, rather than dyes. There
are variations based on whether the glass is ionically coloured or
"struck" (colloidally coloured). Ionically coloured glass is pretty
well bulletproof--you can bleach it if you hit it hard enough, but it'll
recover instantly. Struck glass tends to be a bit more delicate with
respect to bleaching, and requires fairly exact heat treatment, so has
sort of fallen out of favour. It may well be that the Corning stuff was
struck glass.

You can build lasers out of colour centres, so fluorescence is no huge
surprise, but as you say, it's a huge pain.

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

Helpful person

2015-12-09 14:01:45 UTC

Post by Helpful person
That's interesting. I would expect all the manufacturers to use the
same dyes, especially "back in the day". Do you have any theories as
why the Schott and Ohara filters fluoresce? Seems very odd, and of
course very annoying.
http://www.richardfisher.com

I think the glass filters are colour centres, rather than dyes. There
are variations based on whether the glass is ionically coloured or
"struck" (colloidally coloured). Ionically coloured glass is pretty
well bulletproof--you can bleach it if you hit it hard enough, but it'll
recover instantly. Struck glass tends to be a bit more delicate with
respect to bleaching, and requires fairly exact heat treatment, so has
sort of fallen out of favour. It may well be that the Corning stuff was
struck glass.
You can build lasers out of colour centres, so fluorescence is no huge
surprise, but as you say, it's a huge pain.
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

If what you say is correct then you might get some useful information from the people who make laser safety goggle absorbers. However, your requirement for a cheap solution may kill this approach immediately. (I believe the googles, depending on spec, can consist of thin films + absorbers)

http://www.richardfisher.com

Mark Thorson

2015-12-10 05:59:02 UTC

Post by Phil Hobbs
1. Does anyone know who they sold the line to. if anybody, and if
they're still available?

They sold it to Kopp.

http://www.koppglass.com/solutions/colored-filter-glass.php

Phil Hobbs

2015-12-10 16:08:37 UTC