Cheap IR Filters??

[Stingray]

I found a new in package surefire IR filter for $29 on ebay a while back. I thought I got an awesome deal at the time, till I read about the cheaper ways above. I don't know whay I bought it, I don't even have any IR goggles or scopes. Just had to have it when I saw it though.

Steve

 

[Lasernerd]

The infrared Laser Diode in a CD player can really light things up!

 

[flashlightlens]

Wow. I was sure this thread was long gone. I've emailed Astra also to see just how highly they think of their filters.

 

[flash....]

Lasernerd...
What models \ brands od CD players have you seen IR Laser LEDS in?
I have been inside many and I always find the visible 632nM variety.
I used to repair them and have never seen a IR Laser in a consumer unit..

It would be cool if you could alsave these from old players.

 

[The_LED_Museum]

Every audio CD player I know of uses a 780nm near-IR laser diode. This is generally visible as a dim, dull, deep cherry red color; not quite invisible to most people.
The brands I have seen this type of laser in are JVC, Sony, and perhaps Kenwood.

DVD and video disc players use what I believe is a 635nm visible red laser diode.

 

[PhotonWrangler]

[ QUOTE ]
The_LED_Museum said:
Every audio CD player I know of uses a 780nm near-IR laser diode. This is generally visible as a dim, dull, deep cherry red color; not quite invisible to most people.
The brands I have seen this type of laser in are JVC, Sony, and perhaps Kenwood.

DVD and video disc players use what I believe is a 635nm visible red laser diode.

[/ QUOTE ]

Yes, DVD players need the shorter wavelength of the 635nm diodes. I winder if it's just cheaper to mass produce the 635nm units and use them in everything now? This would probably make sense in terms of reducing the manufacturer's inventory of different LDs, and I'm guessing that it also works better with burned CDs as well as the stamped ones.

A lot of laser printers use the Sharp LTO22 series of NIR LDs. These also operate at 780nm, that deep cheery-red glow. They're pretty readily available on the surplus market, either individually or buried within a salvaged collimator housing.

These are pretty rugged little diodes from an electrical standpoint. While I've blown out several 635nm units, I have yet to damage one of the LTO22s from the occasional electrical abuse.

 

[NewBie]

[ QUOTE ]
flashlightlens.com said:
Wow. I was sure this thread was long gone. I've emailed Astra also to see just how highly they think of their filters.

[/ QUOTE ]

Did you hear back yet?

 

[InventaNutta]

Hi Guys, I'm new to this forum. I read this thread and would like to offer my findings on IR illumination...Dead cheap /ubbthreads/images/graemlins/wink.gif

Like many here, I've messed with IR Leds etc, there are only a few that can cut it, the best I found were some german multi-chip beasties, which are not bad, but about £10 each, so these were discounted.

I have 2 russian nightsights, a 1st and 2nd gen, the later cost about £2K I believe, it's 14 inches long with the 'Big' zoom lense & light hood. I have a 6 Volt lantern type lamp, which has good power, (note.. modded for sealed lead acid batt) I researched certain dedicated IR filters, obtaining some samples of the Lee IR 87 filters, light transmission above 730nm etc. These worked ok with my 2D mag-lite. Noting that all things that appear black are not always, I have a 'black' glass ashtray, that is indeed 'Not' black its actually dark red. It actually worked as a crude IR filter when hitting it with lots of light, the drawback being the glass is unnecesarily too thick and heavy. Baring these thoughts in mind, I applied the same to plastics. I obtained some ICI Persex, black of course, this also is indeed dark red. I cut a new lense for the 6V torch, replacing the original. An optical comparison between the Lee IR filter and the Perspex one appeared to have the same dull red glow etc. Tests with the Night sight were good, I could illuminate stuff at about 80 metres, (limited by the distance I could get from my garden). This same cheapy method should work for video cams. Perspex looks usefull..

Steve

 

[InventaNutta]

Webley445's method will stand a lot heat, by the nature of the material etc.. But I'm curious, The E6 transparency film, how does that standup to heat? in say a 35 Watt Halogen spotlight?? methinks melt-down??

Steve

 

[InventaNutta]

[ QUOTE ]
Lasernerd said:
The infrared Laser Diode in a CD player can really light things up!

[/ QUOTE ]Yo Lasernerd /ubbthreads/images/graemlins/smile.gif this is indeed an interesting thought. My Gen 2 nightsight has a 50mW IR laser, focusable from 5 to 200 metres. Sadly when I acquired this sight, the previous owner had blown the laser, by replacing the 2x AA carrier with a PP3 /ubbthreads/images/graemlins/crazy.gif I examined this unit very closely, the photodiode feedback was 'Not' used in there design (which was crap) it was being driven in some weird pulse mode, on a pcb that looked hand drawn. The rest of the unit lense & mechanics are nice. It maybe worth hanging an 'Ex' CD player IR laser in this unit, as I have a couple here. A interesting point on the original Laser, the window of the diode had a small piece of some opaque crystal glued over it? presumably to diffuse the beam (make safe?) On top of that, the back of the focusing lense had a piece of polythene bag stuck to it, more safety?? The sight can be seen here, if the link works? http://uk.f2.pg.photos.yahoo.com/ph/[email protected]/detail?.dir=/f6cb&.dnm=223b.jpg

Any ideas as to the typical power of an IR laser in a CD player?? I doubt if I'm gonna find a 50mW job /ubbthreads/images/graemlins/wink.gif

Steve

 

[Lasernerd]

Flash I want some of those 635nm Diodes!Dont get your eye to close they look dim red but have a punch of IR!
its hit and miss with Cd players I have seen some upto 12mw`s Now these cd burners they have a higher output Diode
not sure of the power..??
A good resource of high power IR laser diodes are in the laser printers some interesting optics also!

 

[InventaNutta]

Heres a source I found for IR Illuminators and IR Filters>> http://www.cobra-optics.co.uk/infra_red.htm They have IR Lasers also Halogen rechargeable spotlights. The 2 IR laser units are very powerful. There's 2 models, one at 75mW and one at 150mW /ubbthreads/images/graemlins/smile.gif (I might have to grab one of these soon) Priced @ $153 & $184 respectively that looks pretty good to me. Both models are 805nm.
IR Filters are also available to make your own IR lamps...

Steve

 

[mastertop]

Does this works ? http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&category=7307&item=7102738309&rd=1 ? (if I buy Ir led, and this filter, could i make an Night vision?)

 

[MikeF]

I have been looking for a source and came across US Night Vision as a source for an Infrared filter that fits on most handheld spotlights. I need a long range illuminator for NV.

 

[oklalawman]

I saw this on another forum so I have not tried it. I heard you can use welders helmet/goggles glass as a filter.

 

[MikeF]

[ QUOTE ]
oklalawman said:
I saw this on another forum so I have not tried it. I heard you can use welders helmet/goggles glass as a filter.

[/ QUOTE ]
That surprises me, you would think that welding lenses would block as much IR and UV as possible to prevent that energy getting to the welder's eyes.

 

[WildRice]

Lasernerd, I useually don't hit this forum, but I thought I would chime in... 635nm LD's are VERY visiable, 632nm is the dominant line in He-Ne lasers. IIRC, the original visiable LD's were about 670nm dark red, the ones in CD players are around 760nm (I think) These are the ones with the dark red emission, and mostly IR. Near IR LD's are all over the place, including ebay. 808nm is the wavelength for YAG lasers, right on the edge of human vision, but works GREAT with GEN I (nightshot). Just beware, anything over a few mW, if colluminated could present a hazard to others.
Jeff

 

[Lasernerd]

yes I am aware 635nm (Red) can be seen,
and yes the original LD platers have a nice little 2-3mw
he-ne I have a few.

 

[peakbeam1]

I could get some "film" for you. I guess you could sandwich it between two pieces of glass. Are you looking for semi-covert 850nm, or fully covert 900nm or 950nm. I am currently looking for a reflector lens systems for an to-66 ir chip has anyone seen anything out there? I could use up to 3" dia.
Thanks
Rob