Post by thread:laser filter.@670nm

I am working on a pic program to decode modulated and amplified, weak, visable laser signals. I am looking for a cheep filter, any ideas?? Thanks for any thoughts....Steve T ____________________________________________________________________ More than just email--Get your FREE Netscape WebMail account today at http://home.netscape.com/netcenter/mail

Hello! > I am working on a pic program to decode modulated and amplified, >weak, visable laser signals. > I am looking for a cheep filter, any ideas?? > Thanks for any thoughts....Steve T If this is a one-off project, this might be a solution: Try getting hold of safety glasses for use with lasers - the are available in various flavours to block/pass various wavelengths. Since you are working with red light, you probably want red glasses to only pass through the red light. ie. You are looking for glasses designed to block out the shorter wavelengths (ble and green). Then butcher the glasses and use the lenses as filters. Cheers Roland

>Hello! > >> I am working on a pic program to decode modulated and amplified, >>weak, visable laser signals. >> I am looking for a cheep filter, any ideas?? >> Thanks for any thoughts....Steve T > >If this is a one-off project, this might be a solution: > >Try getting hold of safety glasses for use with lasers - the are >available in various flavours to block/pass various wavelengths. >Since you are working with red light, you probably want red glasses >to only pass through the red light. ie. You are looking for glasses >designed to block out the shorter wavelengths (ble and green). > >Then butcher the glasses and use the lenses as filters. > >Cheers > Roland Another thing that can be "butchered" is discarded remotes and receiver modules from TVs, VCRs, etc. Sometimes the filter is really IR and is opaque to visible light; sometimes it is just deep red. Even if it's not an exact match for your diode, it may improve the S/N quite a bit by just getting rid of most input at shorter wavelengths. Reg Neale