... FYI, I found a local (Florida) supplier who sells the opt211, a close cousin to the opt210, for about $6 each: http://www.westfloridacomponents.com/ ...
Why not just start out with the K3PGP circuit. It uses an inexpensive BPW34 and a radio shack MPF102 FET. All of the other parts are very commonly available....
... I think 'inverse' mentioned K3PGP, but I hadn't checked it out yet. This is _exactly_ the kind of info that I'm looking for, links to optical project...
... well, I suggest reading this excellent article: http://www.iop.org/EJ/article/0031-9120/41/5/005/pe6_5_005.pdf to summarize: cuprous oxide (Cu2O) like many...
Inverse, That is really interesting. I'll have to give it try! Tnx, John/AF4EX ... to ... how ... been ... the ... heterojunction ... demonstrated. ... impure ...
Hello all. I have taken 2 soda cans with concave and pollished bottoms and cut the tops off them. I am going to wrap black electritians tape on the edges of...
I would have to say start with the K3PGP circuit, its stunningly simple and extremely sensitive, it pays for it with bandwidth however. The 3dB roll off occurs...
... Yes, I will definitely start with the K3PGP circuit. Low bandwidth not a big problem for me at this stage. I've already have obtained a pair of Fresnel...
Hi all, Is it really necessary to expand the beam to a large diameter at the exit of the photon source if the divergence is 2 degrees by 11 degrees??? In the...
Art
KY1K@...
Nov 9, 2008 3:52 am
354
Art, A laser is only better than LEDs if you want to put some light very far away on a rather small area. A laser is very dangerous if the power density is...
In the previous mail you have to read : "A laser is very dangerous if the power density is over 1/10 mW by mm˛ in the first 100 m beam." 73 and Sorry. Yves...
Thanks Yves, Yes, I am aware of the safety issue-I know it's important and I can do the math easily. But, the 2.7 watt laser diode on ebay has a 2 degree by 11...
Art
KY1K@...
Nov 9, 2008 4:54 pm
357
Hi Art! NASA used (or maybe is using) a multiple beam uplink to combat scintillation. Slide six of a slide show...
Art The scintillation problem is not due to the beam divergence but by the laser light nature. With a laser the TX is always seen like a point by the RX and...
Jim, I do not completely agree with this point. The useful beam is always the one that start from the laser to the optical device that receive the light. It is...
These questions are very interesting. It seems important to distinguish widening the beam at its staring point (beam expander) and widening the beam...
Hi Art, ... It's probably been beaten to death already, but given a given set of atmospheric conditions, it's the size of the exit (and entrance) apertures...
... there is another reason: atmospheric turbulence cells, the main reason behind scintillation, are some cm in size. If a beam is being transmitted larger...
Hi all, Because the closure of all the sites referenced in the AOL Internet provider in France, I was constraint to transfer and rewrite my old optical...
We have been measuring the beamwidth of the Luxeon IIIs through a so called 5 degree divergence lens by L2 Optics, L20P005, and getting an answer of 15...
Rex you are right. For example if you use a single low cost LED OP290 with a 10 cm in diameter glass lens with 30 cm focal length you will get very more power...
I'm just learning about this Optical DX hobby, but I just had an idea that might be useful for improving the detection capability of the optical receiver. (Or...
John The problem is different versus the objectives. A photodiode does not work like a radio receiver but like a quantum receiver. Its optical bandwidth is not...
... Yves, Thanks for your explanation. Using narrow-band filters to detect naturally occurring spectral lines sounds like a better way to implement my idea. ...
Hi John, Another common way to sense such things would be to use a spectrometer (http://en.wikipedia.org/wiki/Spectrometer ) - either diffraction-grating or...
John, Have a look at : http://stores.ebay.fr/BJOMEJAG-EBUYER-STORE/Welcome-to-BJOMEJAG-Ebuyer-Store.html 73 Yves ... Yves F1AVY http://f1avyopto.wifeo.com...
Clint and Yves, I appreciate your advice and information. I think I'm beginning to understand now that the "filter approach" would be useful for detecting...
John A CCD camera used in astronomy is a very sensitive device for a static optical flux because it can add energy during very long time. If a telescope is...
Hi All, I think I understand all that's been discussed, although practical values for distances between the multiple transmitters and/or the multiple receivers...
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