Looking for 904 nm LED's

[apchar]

I've looked high and low for 904 nm LED's with fast (< 20nsec) rise-times and decent intensity but haven't found any. Panasonic makes one at 905nm but the rise time is 700nsec! The closest I've found is 890nm from Vishay but I don't know how sharp the IR filters are on guns and detectors.

Does anyone know what make/model LED's manufacturers like Blinder use ??
Thanks,
Apchar

[ELVATO]

Older Blinders used to have 890 (or was it 870?) nm LEDs. I guess you'd have to look at the spec sheet to see how much "spills" into the 904 nm spectrum. The new ones uses LEDs that are a lot closer (if not spot on) 904nm, which could be part of the reason the new stuff is a lot better than the older stuff.

[fulcrum]

These might do the (your) job:

http://www.vishay.com/docs/81313/tshf5210.pdf

I assume its the one you were refering to.

[apchar]

Yup. Those are the ones. But the radiant power is down 25% at 904 nm. You're average photodiode has a spectral bandwidth of 50-100 nm. What is the spectral bandwidth of the avalanche photodiodes they use in LIDAR guns?

[category4]

I think these are what Blinder is currently using.

Product details | Optical Systems | JENOPTIK AG

[apchar]

Thanks Cat4. The wavelength is right but look at the rise-time: 400ns. 10 times longer than the LIDAR pulsewidth, & maybe 100 times longer than the LIDAR's risetime. I don't know this for sure but I'd expect the detectors in the LIDAR guns are AC coupled for sun/noise immunity. I'm surprised that such a slow risetime would survive the high pass filter. But they obviously work or blinder wouldn't use them.
I see Jenoptic has faster units (35-70nsec) in the same family (the 905-545 & 900-335). But they are weaker. Maybe power and speed are mutually exclusive.
I'll try them all if I can find someone the the states that sells them. They have a rep here but probably won't be interested in small quantities.
I notice that peak wavelength is specified at a particular current, implying the spectrum is not just a function of geometry. But no one describes the relation. I'll try to cobble a spectrometer (blank CD + ruler + dark room + webcam) together and characterize it & post the results here if anyone is interested.

[200Volts]

I'm no EE, but it appears that only laser LEDs have that kind of rise time. You can find 1mW 890nms for $0.50 or 25W for $55.00(probably overkill and dangerous).

I have a white Prius with 3M clear bra material on the front and headlights. I wonder how much IR this absorbs.

[Stealth Stalker]

Not enough to make the slightest difference to a laser gun.

If you have no jammer, you have no protection. Period.

[200Volts]

I found a source for laser Diodes with 1ns rise and 2ns fall times.
us-lasers .com/irlasdio.htm
5mW samples are $33 each.
So if we got 1 or 2 of these, then pulsed them at 100 PPS, etc would this be an effective jammer?

[skatman]

I found a source for laser Diodes with 1ns rise and 2ns fall times.
us-lasers .com/irlasdio.htm
5mW samples are $33 each.
So if we got 1 or 2 of these, then pulsed them at 100 PPS, etc would this be an effective jammer?

You have to pipe them through an optical beam expander. Otherwise the beam might be too narrow.
Also have to see what pattern the lidar gun is putting out. Just blasting a periodic pattern with arbitrary frequency is useless because this is probably filtered out in gun's software.

Laser diodes is the way to go. The most powerful you can find... I believe that 5mW is close the limit.