The CASER effect Solar Cell!

Ok it works but where do you take the current for the LED? and what is you intention in converting current to light and again to current? Why do not use the already available current? Why lose so much energy for nothing?

If you expect to build up a machine with an over 1 gain in energy you will invest you inventor creativity in a non productive manner.

By the way how is your rotary jet engine working? Any progress or it is now waiting for new ideas? Good results with respect to efficiency as you claimed It will bring?

The next phenomenon to catch my attention was the tremendous improvement made in LED's ( Light emitting diodes) in recent years. Luxeon star now has a white LED that emits light at 600 Candelas, (that's right 600 candelas not millicandelas) at a power dissipation of just 1 watt (3.3V and 350 ma).

Would you, please, provide a link to this information? I tried Philips site but I couldn't find it.

http://www.luxeonstar.com/

Thank you

This set me to wondering whether it would be possible to artificially irradiate solar cells with LEDs in order to produce electricity....

In fact if properly designed the solar cell should actually produce more current than is used to power the LEDs. In other words the whole system acts like an amplifier. Hence the term CASER effect solar cell, Current Amplification through stimulated Emission of Radiation

Sorry but it doesn't work that way. Any process where energy undergoes a conversion from one form to another will always lose more energy than gain. The more conversions, the greater the compound loss. Anything other than this is an overunity system.

Have a really good look at the theory behind solar panels (the conversion efficiency and the wavelengths they work best at) first before continuing. Also look at the theory on sun energy output and wavelengths and compare to incandescent and LED output and wavelengths. Then calculate number of LEDs necessary to produce x amount of power out of a solar panel (taking into account solar panel conversion efficiencies of about 25%) and compare to how much current the LEDs require to produce that light. You will find that due to energy conversion inefficiencies it isn't possible.

There is plenty of info on the web.

Sorry but it doesn't work that way. Any process where energy undergoes a conversion from one form to another will always lose more energy than gain. The more conversions, the greater the compound loss. Anything other than this is an overunity system.

Have a really good look at the theory behind solar panels (the conversion efficiency and the wavelengths they work best at) first before continuing. Also look at the theory on sun energy output and wavelengths and compare to incandescent and LED output and wavelengths. Then calculate number of LEDs necessary to produce x amount of power out of a solar panel (taking into account solar panel conversion efficiencies of about 25%) and compare to how much current the LEDs require to produce that light. You will find that due to energy conversion inefficiencies it isn't possible.

Hi ! A very succinct and knowledgeable post. Yes, I have roughly followed the course charted out by you. Working mainly with an amorphous silicon solar cell and irradiating it with LEDs of different colours and frequencies as I had previously outlined.

The great thing about LED's is that they emit over a very narrow band of frequencies. The white LEDs I am using are mainly phosphor based i.e., the LED emits in the blue frequency and excites the phosphor which in turn emits 'white ' light but even here the frequencies are centred around the blue.

The sun, at the equator, radiates about 1000W/sq.m at midday. The amount of energy available to the solar cell depends upon its efficiency. Thus a cell that is 10% efficient would produce about 100W/ sqm under these conditions.

The thing that caught my attention was that solar cells work on the internal photoelectric principle. Most of the energy in sunlight is therefore wasted, a lot of the energy is not used at all. . The use of LEDs allows a more accurate study of this effect. I think there maybe some scope for error in the present theory i.e., that anything over the band-gap energy (in the case of silicon it is about 1.2eV. ) will result in a flow of current. The reason I say this is that in the case of LEDs only energies of about 2.4eV result in light emission. So maybe the reverse is true also? Just a thought. Even in the experiments I have done, anything less than blue ( which is in the 500 nm range) does not have much of an effect. Green, ultraviolet, yellow etc., do not work very well.

So, my theory is that the blue light would result in charge separation (i.e., voltage generation) while the flow of current is mainly due to the intrinsic property of the silicon to produce current when heated, which means irradiation by long infrared.

In any case I think it is an interesting avenue to pursue. After all if it is possible to amplify radio signals from tiny values to significant ones, the same might also hold true for current amplification as applied to solar cells.

Lastly is this really energy conversion we are discussing or energy amplification, which would be a completely different matter.

In fact if properly designed the solar cell should actually produce more current than is used to power the LEDs. In other words the whole system acts like an amplifier. Hence the term CASER effect solar cell, Current Amplification through stimulated Emission of Radiation

Lastly is this really energy conversion we are discussing or energy amplification, which would be a completely different matter.

If we were talking about a valve, transistor or a laser then yes, but this is about a solar panel powering an array of LEDs which produce light, which is harnessed by the solar panel to power the LEDs (a closed system, self-sustaining perpetual energy system), not about using a small current to control a larger current (transistor or valve amplification).

If we were talking about a valve, transistor or a laser then yes, but this is about a solar panel powering an array of LEDs which produce light, which is harnessed by the solar panel to power the LEDs (a closed system, self-sustaining perpetual energy system), not about using a small current to control a larger current (transistor or valve amplification).

Yes, I have been thinking about that and perhaps the comparison was wanting. A better one would be a magnifying glass placed in sunlight at the correct angle, it is hotter on the side away from the sun than on the side facing the sun, could this be considered as heat amplification ?

In order to understand where I am coming from, you would have to take a solar panel into the sun and measure the output, it is quite magical. It is so magical that it is impossible not to take the panel inside out of the sun and try to duplicate the results. Eventually some-one will come up with just the right mix and voila. It's got to happen.

OK so it is like trying to squeeze water from a stone. If you squeeze hard enough who knows. For one thing the anti-reflection coating on the silicon cell should be removed, the LEDs should be housed in as highly reflective and well designed a housing as possible from which no light escapes and so on., Anyway it is interesting, if nothing else.

Light is not mechanical, it does not follow the usual laws of mechanics, so let's see. I'm sure some one is going to come up with a eureka kind of situation here.

Yes, I have been thinking about that and perhaps the comparison was wanting. A better one would be a magnifying glass placed in sunlight at the correct angle, it is hotter on the side away from the sun than on the side facing the sun, could this be considered as heat amplification ?

A better term would be "light concentration". Remember the rays of light are being focused to a single point by the magnifying glass. The energy is the same going into the magnifying glass as it is coming out.

Light is not mechanical, it does not follow the usual laws of mechanics, so let's see. I'm sure some one is going to come up with a eureka kind of situation here.

Woo there, don't forget that light is simply made up of particles and waves. It follows the same laws as the rest of us.

OK so it is like trying to squeeze water from a stone. If you squeeze hard enough who knows

Have a look at the Wikipedia entry "Concentrating solar power". The efficiency of the solar panels is increased by concentrating the suns rays on to a small area of silicon solar panels but at the cost of added complex aiming and sun-tracking mirrors and heat buildup in the solar panels (degrading panel life).

There is nothing magical about the standard silicon-based solar panel, it has its problems (poor efficiency and high cost in terms of materials and energy to manufacture) but there are plenty of new solar technologies being developed that are cheaper and/or more efficient.

Have a look at some of the previous threads and posts regarding solar technology on CR4 and google search solar cell theory and applications for more information. A little more knowledge should help you focus your efforts and ideas in the right direction.

Woo there, don't forget that light is simply made up of particles and waves. It follows the same laws as the rest of us.

I thought that light was both a particle AND a wave. There is a difference. It is not made up of particles and waves but possesses both properties but never simultaneously. At least that is the view given in the Nobel archives. Further light can, or rather does disembody itself, meaning it can be in two places at one and the same time, as is demonstrated by the double slit exsperiment. Further light does not follow the same l;aws as the rest of us, its speed is constant, meaning if one beam of light is travelling at 160 Kmh towards another that is approaching at 250 kms, the speed of the two beams is not 410 kms but a constant 300kms

I am not trying to be contentious, its just that these are the generally accepted properties of light.

To keep the discussion simple I ignored the developing principles of quantum physics, mechanics and wave particle theory because in this case they are not relevant in this particular example of attempted-over-unity energy generation. Remember, the theory and operation of the LED, incandescent bulb and silicon solar panel are very well known and proven.

New solar cell technologies are being developed that could utilise advances in these principles, but that is a base-line design and manufacturing change to the fundamental ways solar cells work and convert light, not something someone can do in their backyard (without a lot of knowledge and equipment).

Have a look on the web for the latest solar cell and panel developments. There are a few groups that are working on this (with modest results).

A better one would be a magnifying glass placed in sunlight at the correct angle, it is hotter on the side away from the sun than on the side facing the sun, could this be considered as heat amplification ?

Oh no! it is not amplification of heat which is ENERGY but of temperature which is POTENTIAL. The reason temperature increases is that energy is concentrated on a smaller surface and its higher density creates a higher temperature differential to the environment. The energy is proportional to the area of the harvesting surface (the lens in this case) and the density of energy flux (the sun emitted light). In the lens there are losses depending on the transparency of it which is not same for all frequencies in the white light. The energy present on the concentrating spot is less than the one found on to the sun lens directed surface but concentrated on a much smaller area.

In your analysis you mix two different notions energy and potential thus your error.

But you did not answer my question with respect to your rotary jet engine.

Hi Nick! Thanks for your query about the Rotary Pulse Jet Engine. You know that the Rocket (at least the modern version) was invented in America. As a rule Americans are quite susceptible to rockets and rocketry, after all they put a man on the moon using this science. So it surprises me that people should be so blind to using this technology in more prosaic forms. At the very least it should be given a try.
With the panic that is setting in, you read every day about the Prius and the Beare engine, and the ROPE (rotary opposed piston engine) and the quasiturbine, but hardly ever about the rotary pulse jet, except within these forums. Does that answer your question?

You know that the Rocket (at least the modern version) was invented in America.

No, the modern version was designed, built, and tested in Germany. After the WW2 the victors have had, in their spoils, German engineers who have developed V1 and V2 rockets. Von Brown (the chief designer of the German rockets) was one of the principals at NASA. And they came with the magnificent devices that put the men on the moon and brought them back. Russians have taken some of the rocket technology and people, and developed them, too. At the '70 level, I have seen their Dvina and Volkhov land to air rocket stations. All the labels where written with Cyrillic characters (the Russian writing) but the technical names were...German. So much for Russian inventivity!

By the way, you haven't answer my question about that very bright LED.

The first analysis of rocket engines was written by a russian with name of Tziolkowsky.

Germans had 2 basic research places for rockets one was Pennemünde where von Braun worked and an other one which appears only once in a writing of Churchil. The second was occupied by the soviets. von Braun's team moved west at the end of the war and went to the american army to give them selves. It was an amusing story. At the start developpment in the US was also lead by the navy. But their first developpment exploded in the lounch site. For patriotic reasons von Braun's rocket was not allowed to be the first to fly although ready. This is in fact the reason why the russians had the first satelite send before the US.

I am sorry but the inventor of the modern day rocket is universally acknowledged to be Robert Goddard of the US. True the Germans did take the subject further but unarguably it was Goddard and also possibly the Russians in the person of Tsivilosky, although his contribution was theoretical rather than practical who were the pioneers in this scinece.

I found out something new, thank you. We, then, should include Hermann Obert (who was my father's physics professor).

Still, what is the link for that LED? Pleeez!

Hi indel,

Here is the link you asked for as you can see http://www.philipslumileds.com/pdfs/ds23.pdf

on page 6 there is actually a red 1 watt Led that rates at 810 Candelas. LEDs have been improving at a terrific rate, from 130 Candela in 2003 which was considered a breakthrough till now at 810 Candelas and counting.

Thank you

Gentlemen,

We did not yet finish the last discussion about energy from nothing and we get a new one genial perpetuum mobile.

In one of the threads about a technical problem I found a very true and well formulated comment:

"Low knowledge is dangerous"

It is quite interesting that during last few months we had somebody who criticised scientists not to do enough to go over the basic rules of thermodynamics, a couple of comments about the Tesla machines to harvest energy from the surroundings, generators running for 20 years already in a small swiss town and providing energy from nothing, now we are proposed a current generator which uses current to make light and the same light to generate current!

I am asking myself what have those inventors learned what schools did they visit and who was the professor who gave such a tuition that they can claim to obtain efficiencies over one.

I am not saying that we know all, by far we do not, but I have the bad feeling that CR4 becomes a site for science fiction and I am very sad.

The area between fact and fiction can be very gray indeed, making the line between them rather hard to see sometimes (especially for those with the enthusiasm but lacking in the knowledge and experience).

Part of the purpose of CR4 is to learn, so I am happy to help people who may not know just where that line is (especially if they are willing to actually listen and learn, and aren't scammers).

As for over-unity and free energy, if there is a thread (and it hasn't been blocked yet), you will probably find me there to help offer advise to those that are willing to listen and are keen to learn (or to brow-beat obvious scammers with facts and logic).

I totally agree with you that we have to help but what is strongly disappointing me is the fact that those enthusiastic persons reject any comment which is not on their track. Even if we are willing to help them understand their errors they (with one exception which has all my respect) are not willing to accept our corrections.

Hi! Nick. OK, so what is there to grouch about, it's not going to take millions to verify if it is possible or not. What about bosons and fermions ? Boson can exist in many states and in unlimited numbers while fermions (electrons for instance) exist in restricted states. But maybe all this is a bit premature, the very fact that a 0.03W LED can produce the same voltage when irradiating a solar cell as a 100W bulb working on 230V should give food for thought.

I think it is because you mentioned you are trying to use a 100W bulb and a solar panel to try and get more than 100W out (hence over-unity generation), which breaks numerous laws. You will be able to get the efficiency above what you are already getting (2.8V@3.5mA=9.8mW), but it is never going to be close to 12V@8.3A (100W) (or put another way, an increase in conversion efficiency of 5 orders of magnitude).

I think it is because you mentioned you are trying to use a 100W bulb and a solar panel to try and get more than 100W out (hence over-unity generation), which breaks numerous laws.

I think there is a slight misunderstanding here, I am not trying to irradiate a solar panel with a 100W bulb and trying to get 100W out of the panel. I am just trying to see how efficiently small amounts of power can be used to get the same effect as with a 100W bulb.

You will be able to get the efficiency above what you are already getting (2.8V@3.5mA=9.8mW), but it is never going to be close to 12V@8.3A (100W) (or put another way, an increase in conversion efficiency of 5 orders of magnitude).

Secondly your calculations are wrong 3.5ma is equal to 0.035amps so it actually works out to 0.08W and not 0.8W. That works out to 12,500 times less than 100W. So there is scope in this direction as I was trying to say.

Secondly your calculations are wrong 3.5ma is equal to 0.035amps

If those are your calculations they are wrong since 3.5 mA=

3.5/1000 A = 0.0035 A you miss a zero.

Yes I realised I made a mistake after I posted last night, 100W/0.0098W is roughly equal to a difference of 10,000, which is 4 orders of magnitude not 5.

You have two errors in your calculations also. There are 1000mA in 1A, not 100. Also 100/0.8 is 125 times, not 12,500.

I think there is a slight misunderstanding here, I am not trying to irradiate a solar panel with a 100W bulb and trying to get 100W out of the panel. I am just trying to see how efficiently small amounts of power can be used to get the same effect as with a 100W bulb.

I was hoping that was the case, but you did also mention and indicate in a few different posts over-unity generation. Be very careful describing your application and points of view as people can only read your posts here and elsewhere on CR4, not your mind.

You should really have a close look at the theory behind incandescent bulbs and LEDs, then look at manufacturer data sheets and websites. That will give you a really good starting point to what you can actually get out of them before you even start testing, and give you known reference data to test against.

The panel in question which was about 15cm x 15cm (6" x 6") generated about 12Volts and 0.3 amps or something like 5 watts. You do not mention under which light conditions this power was obtained. If we assume that it was at noon and during a sunny day the solar power is about 1kW/m^2. The panel area is 0.15x0.15=2.25E-2 m^2 and receives a power of 22.5W. You get 5 W as outlet power so that you have an efficiency of 5/22.5= 22.2%!!!

When irradiated by a 100W incandescent working at 230V the cell registered 2.8V, the same solar cell irradiated by an array of four parallel connected LEDs working at 16ma and 3 V produced 2.67V, interesting huh! I presume that was obtained with an open circuit i.e. with no current. Is it true? If not please indicate the load value ( the value of the resistor connected between the two wires) and the current you measured. Since the power converted by the panel depends on the incomming power it will be good to give informations about: the distance between the bulb, LEDs and panel. I am sure the LEDs were very near to the panel and focused on it (LEDs have a lens integrated and thus a narrow light emitting angle). The bulb emitted its light all around and only a limited amount was falling on the panel.

While the 100W incandescent produced 3.5 ma the LED array produced only 0.85 ma (that is not even one milliamp!) In sunlight 4.5 ma were produced.

Same remark as above which load was connected since if you take the voltage of an open circuit and the current of an other configuration the results cannot be compared.

So in effect the solar cell can be made to produce appreciable amounts of current using LEDs. In fact if properly designed the solar cell should actually produce more current than is used to power the LEDs. In other words the whole system acts like an amplifier. Hence the term CASER effect solar cell, Current Amplification through stimulated Emission of Radiation!

In fact what you claim is "generating power from nothing". It is exactly what I mentioned in previous comments.

I do not want -I insist on it- to say that all what we know today will not evolute but I want to see proofs, correct from the physics point of view, and which show that a law accepted since many many years and proven by many many experiments is not any more valid. So please describe the conditions under which you obtained your results and why you believe that an over 1 efficiency is possible. If you bring the proof then I shall say that you are right till then I cannot say that.

There is a German proverb I very much like: Paper is patient, it accepts everything!

This post is by way of being an apology to Jack of all trades (AND to Nick, I hope this acceptable) , who after all have been the embodiment of patience. The best way I can think of to explain the CASER concept is by a practical illustration.

OK, take a Sanyo amorphous solar cell No: AM-7D08 which has an output of 7V at 190 ma. ( 1.33 W, in actual fact I have often found that in practice these figures are often exceeded.)and dimensions of 150cms x 110 cms (6" x 4") Let us suppose that this solar cell is irradiated by an array of 18 white LEDs working at 3V and 10 ma and 18 infrared LEDs ( they have to be of the correct kind) working at 1.5V and 13ma . These would have to be placed in a special housing about 1.5 cms from the solar cell surface and built of extremely good reflecting material. (Like the ones one sees in LED torches now-a-days). Ideally the anti-reflective coating of the solar cell would be eliminated. So the power input would be 0.54W for the white LEDs and 0.35 W for the infra red LEDs . Or a total of 0.89 W . Suppose irradiation of the solar cell by the LED array yields 6V and 150ma. = 0.91W. So you see what I mean? The output is 0.003W greater than the input. That's the kind of thing I am hoping will be possible.

Suppose irradiation of the solar cell by the LED array yields 6V and 150ma. = 0.91W.

Why limit? if we are on the supposition plane and not on the facts plane we can suppose the output will 12V and 1.5A so we suppose to get 18 W. As I wrote paper is very patient we can write on it all what we want, it will accept. Human beings and especially technically trained are less able to accept non factual suppositions. I am one of those I believe ONLY what is for me serious enough to believe. So please excuse me but your suppositions do not at all convince me.

Could you give an answer to my questions about the load on the voltaic panel? Did you measure voltage AND current with same load?

What I wanted to know with respect to your engine is not what other do or think but how your own development work did evolute. As you remember it was a discussion about efficiency and you did not accept the comments indicating that a jet engine will not be more efficient than a classical piston one but on the contrary.

I am not trying to limit anything, I am just attempting to provide details of an experiment

that anyone with access to the materials could perform. Further the figures for the solar cel of 12V and 18W which you have pulled out of thin air, I have taken from the Sanyo fact sheet.
Both the current and the voltage refer to the open circuit current and voltage, maximum power that can be produced by the cell will fall close to but slightly less than these two figures. If more accurate online measurements are required all that need be done is to connect the measuring device serially with the load. And to connect another voltmeter in parallel so that both current and voltage can be monitored simultaneously. However the figures given in the Sanyo fact sheet are based on levels of illumination.

As you remember it was a discussion about efficiency and you did not accept the comments indicating that a jet engine will not be more efficient than a classical piston one but on the contrary.

This I protest is mere pedagogy, how can you say that the piston engine is more efficient than a rocket one with so much surety and without experiment. I am sorry but this seems to be a fruitless discussion.

Dear Sir,

Your last word is a true conclusion: it is a fruit less discussion good luck and good by.

In fact you confirm exactly what I gave as answer to Jack a couple of comments above.

I hope that you creativity will bring you the pleasure of success but first I would suggest you take a couple of books, read them, read what articles were recommended and think about all over,

Nick name

Here are some recent articles for you to look at regarding some developments in the area you are interested in.

Solar material absorbs entire spectrum

http://www.planetanalog.com/showArticle.jhtml;jsessionid=BGP0Y0JAUWMKAQSNDLOSKH0CJUNN2JVN?articleID=211600329

Solar fundamentals and developments (including those using quantium principles)

http://www.tinaja.com/glib/pvlect2.pdf

Solar thermal technology heats up

http://www.planetanalog.com/showArticle.jhtml;jsessionid=G3HVZHFDK5YZGQSNDLOSKH0CJUNN2JVN?articleID=209100356

These may give you some ideas. There are plenty of other developments being worked on.

Thanks I appreciate the pointers. However one of the great drawbacks of solar cells is that they are far too dependent on the weather and without some sort of efficient storage system are no more than mere novelties. The majority of households need power during the night, when of course solar cells won't work no matter how sensitive they are to the spectrum. Secondly I cannot imagine a power supply that is guided by seasonal weather, it is just too uncertain and impractical.

There is not much point in arguing, IF there is even the slightest chance that such a thing as the CASER effect exists, it should be looked into. Think about it, this has all the characteristics of a LASER or a MASER, selective frequencies, amplification and re-inforcement through reflection, stimulation through selective emission of radiation and so on. The materials I have outlined for the experiment do not cost much, little expertise is needed. All that is necessary is availability of materials, which , unfortunately, I do not have here. Otherwise I would have done the experiments and published the results.

Secondly I cannot imagine a power supply that is guided by seasonal weather, it is just too uncertain and impractical.

Which is why they are no good for supplying base-load (when being used as a grid transmission power supply). Wind turbines also suffer from this drawback.

There is not much point in arguing, IF there is even the slightest chance that such a thing as the CASER effect exists, it should be looked into. Think about it, this has all the characteristics of a LASER or a MASER, selective frequencies, amplification and re-inforcement through reflection, stimulation through selective emission of radiation and so on.

Yes, but don't forget a laser or maser use more energy than they output. The output is impressive, but is still a focusing of the input power (no additional power magically appears or is created thru the lasing process). This makes sense, if the process was over-unity then (for example) you could take 100 magnifying glasses, put them in series and create a powerful laser. Don't confuse energy concentration to a single point (laser) with over-unity energy creation (solar panel powering LEDs powering solar panel).

Yes, but don't forget a laser or maser use more energy than they output. The output is impressive, but is still a focusing of the input power (no additional power magically appears or is created thru the lasing process). This makes sense, if the process was over-unity then (for example) you could take 100 magnifying glasses, put them in series and create a powerful laser. Don't confuse energy concentration to a single point (laser) with over-unity energy creation (solar panel powering LEDs powering solar panel).

Right! But if you look at a LED pointer the amount of energy transformed is impressive. The beam or dot can travel more than half a kilometre and still be visible. (I live in the mountains so it is easy to verify this. )

Can you imagine concentrating the light from a 1.5V pen torch with a small 2.5V or 3V incandescent bulb in the hope it would travel so far.

I know that we are talking about two different types of light incoherent and coherent, I still think it is impressive and so should you! Conventional lasers use enormous amounts of power. OK a diode laser is still nowhere near over-unity, but in what sense are we talking about unity here. The beam from a laser diode travels a half-kilometre and is still visible and still fairly tight, right, how exactly do you rate this? In terms of watts ? I don't think so. So what exactly is unity in this case. Could you explain.

As a really simple explanation (without going into specific details and numbers), power in vs power out. In the case of a laser pointer - current goes in, undergoes a conversion to light and the light comes out and hits a target surface. That target surface absorbs (and reflects) the energy (as effectively heat). So what you have is still an energy transfer like you would with a battery connected to a resistor, but in the case of the laser pointer the energy undergoes an additional conversion to light.

A similar example would be converting current to light, feeding it down a fibre-optic cable and converting it back to current at the other end to power a load.

So what exactly is unity in this case. Could you explain.

I would classify unity conversion as the light pointer using 1mW of power and being able to convert and transfer that entire 1mW of power (in the form of heating energy) onto the surface of an object in an ideal environment (ie- ignoring surface reflectance, atmospheric losses, etc).

The beam from a laser diode travels a half-kilometre and is still visible and still fairly tight, right, how exactly do you rate this? In terms of watts ?

Depends on three main things - the power output of the light source, the focusing of the beam and local conditions. You can buy diode lasers that are powerful enough and focused enough to hit the moon, they are not multi-megawatt death rays.

There is a small correction to the information I had posted, and this is that a 5 mw green laser has an operating distance of 2 miles and not half a kilometer as I had originally stated 2m is equal to about 3.2 Km. So using just 0.005W or so, this tiny device can project a visible beam more than 3.3Km, it is staggering when you think about it ! Most people don't think about it they just take for granted. You had made a big concession when you stated that if 1mw is used to power the diode almost all of that 1mw goes into the beam. Green light is very energetic, about 2.4 eV, therefore it needs a lot more energy to propagate a given distance than say red light, therefore if someone was computing this problem theoretically, they would immediately say that such a thing is not possible ! So, all I am trying to say is that there is scope for experimentation here, let's not get bogged down in what is theoretically possible or impossible.

How does a laser diode work?

A laser diode resembles a light emitting diode, in which electrons flowing across a p-n junction (in a diode) find themselves in conduction levels of the p semiconductor, with lots of excess energy. These excited electrons give up their excess energy by emitting light and they drop down into empty valence levels with much less energy. In a laser diode, the region in which this energy release occurs is a very narrow channel with mirrored ends. Instead of emitting their light spontaneously, the electrons experience stimulated emission. Light bounces back and forth between the ends of the channel and is amplified as it passes new excited electrons. Because all of the light produced by a laser diode emerges from one end of this very narrow channel, it experiences severe diffraction and spreads out into a wide, cone-shaped beam. To convert this cone of light into a narrow beam, a converging lens is usually attached to the diode laser's housing and this lens bends the beam into a fine pencil of light. Most laser diodes operate in the red or infrared portion of the spectrum, although some laser diodes that emit blue light have recently been developed.

Hi! I thought I'd tweak this discussion a bit, above is given an explanation (albeit elementary) of how exactly laser pointers (laser diodes ) work. As you can see, stimulation of electrons by the right frequency photons does work and results in a cascading effect. Another plus point for the CASER effect. Current amplification through the stimulated emission of radiation. That bit about an intial divergent beam sounds good!