picking a filter

You will need to contact an optical component manufacturer to find out what they can make.

You need either a 565nm bandpass filter or a 532nm band stop filter.... Both will be costly!

Try Edmunds Scientific for a start...

I'd suggest he needs both (band-pass & band-stop). Chances are the excitation illumination will be way more intense than the signal, so he'll need all the filtering he can afford.

Good idea to contact optics suppliers direct.

Hello sdonahue199:

Why could you not study a simple science?

What I say you may already be aware of but I will also list some sites that are very relevant to your project.

You have to be certain exactly what you are measuring!

As if you are using a 'standard' fluorescent lamp, the wavelength, and temperature depends on several factors.

1) The glass type..........As this effect the amount and way 'light' in emitted. It acts as a filter and you need to know the light the clear glass from a lamp (if that is your source) lets through.

2) The type of fluorescent and phosphorescent..........

These vary and you need to know the quantities of fluorescent and phosphorescent compounds as these will effect the type, wavelength, and heat of the radiation.

That said, you may be using any of several different fluorescing sources and these may not of course have glass between the radiation and receiver diode. Are you measuring the fluorescence from a specific type of compound in black light?.......... As I say you are probably more familiar with these terms so I do not need to explain further.

These sites, with emphasis on the first site will help you decide on a filter and, what light or more correctly, 'radiation' you choose to measure. You may have to 'work backwards' from measuring general emitted radiation, gradually adding filters to allow you to test or measure certain frequencies. These compounds used in lamps, including some other compounds from your description are in the 'green' spectrum. As you may know if you are measuring emitted radiation from a lamp, you need to know the amount and combination of fluorescent and phosphorescent compounds to be able to filter to your needs.

If this is the case, you may need to ask the manufacturer of the lamp what exactly they use as a ratio to give the type of heat and wavelength for that type and use of that lamp.

http://nemesis.lonestar.org/reference/electricity/fluorescent/lamps.html

http://en.wikipedia.org/wiki/Fluorescence#Lighting

http://en.wikipedia.org/wiki/Phosphorescence

http://en.wikipedia.org/wiki/Phosphorescence#Common_components_in_phosphorescent_materials

http://en.wikipedia.org/wiki/Fluorescence#Rules

http://en.wikipedia.org/wiki/Boltzmann_distribution

How are you radiating your specimen?

It may help if you can get a photo-diode closer to your required wavelength? Just a thought.

Why are you doing this?

It would be helpful if you were to give some more specific info' on exactly what and how you are measuring? It will make things a lot easier and get past the fog of your OP statement.

I wish you luck, and feel you should expect to have very deep pockets as this kind of test requires very expensive items. If you know withing a limited range, the spectrum you want or need to measure it will also save on a lot of duplication of tests.

Hello sdonahue199:

Take a look at this thread of a few months ago, I was trying to help on it. But your requirement is nothing like as precise as needed on that thread. However, there is several observations from a scientist in this same field.

http://cr4.globalspec.com/thread/30751#comment336991

Channel electron multipliers are also used but they work in vacuum.

I forgot to ask, are you working in a vacuum or open air?

I can eliminate this type of sensor if you work in open air.

Take care...................

Another thought - what is the spectral response of your photodiode like? How far down is the response at 565nm and 532nm?

If it's like the Hamamatsu S1087 ...

... it'll already have a filter to cut out the longer wavelengths, but the response won't be down very far at 532nm.

May be better to start with one with a sharper peak at as near 565nm as you can get, or to use an unfiltered one, and do all the filtering externally.

You can use what is called a spike filter. It will pass a small band centered on 560nm very efficiently and block everything else. A second option is an edge filter with a cutoff in the region between 532nm and 560nm. Either one would work.