Science a GoGo's Home Page Forums General Discussion General Science Discussion Forum light speed

I personally had GaAs and GaAsP diode lasers in the 70's. Where did you go to school?

Texas state technical institute of Amarillo. AAS in laser electro optics technology. yes, diode lasers existed in the 70's but they were not that common. there was little use for them then, and the most common uses required a lot more energy. one of the most common at that time was the hene lasers. they were used as pointers before the diode laser began to be more user friendly. most research had been done with co2, argon and such like gas lasers. after the kinks were worked out in tunable dye lasers they were used for most of the research. oil companies frequently used co2 for the research they needed lasers for and henes were used for leveling and such. only after diode lasers became more powerful, cheaper and longer lasting did they start to replace hene in many applications. that does not make them the only type of laser existing. in fact i don't think that even today do they make up the majority of lasers. in this i could be wrong. I have not done a lot of reading up on lasers for a while, not since i could no longer work in the field.

dehammer wrote:
"yes, diode lasers existed in the 70's but they were not that common."

They were in my lab.

Either way it renders your original statement invalid. Perhaps you would wish to acknowledge that you were in error?

DA
Look at all the times that you have been wrong!!!

Where are your acknowledgement'(s)...

here's mine by the way... I dont know SQUAT about lasers basicaly.

how about a hollow earth?
how about gravity has gravity?

why didnt you ever reply to my questions about the oblong earths gravity?

avoidance doesnt make it go away it just avoids it.

____DA__WROTE:_____________
Here's a hopefully useful analogy. Stand out in the sun on a hot day and look at the top of your hand. Nothing is burning. Focus that light through a lens (losing 5-10% of the energy) onto your hand and you will be in a world of pain.

Nothing increases. What you are getting is focus.
____________________________

OK... you know where the earth is , and its distance from the sun.

now build a imaginary "hollow sphere that big"
the sun in its center.

insert everyone that ever existed and billions more standing on the inside surface of this sphere.

let them do the same " hold a magnifying glass and point it at their hand"

then measure the total area that is being heated
in all the hands...

what would the total heated area be?
more than the surface area of the sun?
if not remove the people and keep only the magnifying glasses and the sphere.
except add a few hundred thousand billion more magnifying glasses to focus the suns light energy onto the spheres inside surface...

now is it bigger?

now with the(losing 5-10% of the energy) loss you speak of how much heat (energy) do we now have?

how much did we begin with?

was there any type of increase?

was there any type of energy used other than the suns energy?

your reply...

show me where i ever said they did not exist.

show me what this has to do with wheither or not there is an increase in energy from putting mirrors on a ruby.

anothe point, i said "all laser cavities". diodes dont have laser cavities.

dehammer wrote:
"show me where i ever said they did not exist."

I grow weary of your inability to remember what you have written or to understand what others write. Here it is:

"i went to college in the 1980's. at that time there were no such thing as total reflective mirrors on both sides of all laser cavities."

My reference was to TIR not to totally reflective mirrors on both sides of anything. I find it almost incomprehensible that you actually went to college so ... Look up YOYO in an internet dictionary if you don't know what it means. Because that is where this thread has led.

you grow weary of me not remembering, yet you cant find where i said that LED's did not exist. since you claim i did, maybe its your memory that is messed up.

i find it incomprehensible that someone with no more manners than you and no better ability to read can be a college instructor. you cant even post only threads that support your arguements rather that a good percentage of the time posting ones that destroy your arguement. all of my comments earlier were about lasers with cavities and things and you then attacked me about it. i might have missed a small point but it appeared at one point that you were claiming that all lasers did not use mirrors. even diode lasers used mirroring. IF you understood anything about lasers you would know that. the only difference bewteen normal type cavity lasers and diodes is that the mirroring effect is done by polishing the ends of the diode, rather than putting mirrors at the end of the cavity. otherwise it would not reflect. this and the fact that you claim that diodes dont use mirroring effect proves that you know nothing about lasers. any body can use a cookbook to follow a recipte, but a chief understands how everything comes together. It would appear from your writing that you were following a "cookbook" approach to making lasers (or most likely buying them) to appear cool or something. that does not mean you took the time to understand it.

Dehammer,
I respect your opinion and think that you may know a thing or two. Please don't take this personally, but you ought to take a critical writing course. I think that most of your problem is that you can't effectively communicate your point. I think people get frustrated with you because your posts are largely unintelligible. Example

"any body can use a cookbook to follow a recipte, but a chief understands how everything comes together."

Anybody is one word, it's spelled recipe, and you mean chef not chief. I know it's menial but it's frustrating trying to figure out what we thought you meant.

______DA WROTE ______________________________

No Paul you can not get something for nothing. You can take the energy in your battery and produce coherent light from it. But you will, at best, get a few percent efficiency with your ruby. It is the coherency that counts.

Here's a hopefully useful analogy. Stand out in the sun on a hot day and look at the top of your hand. Nothing is burning. Focus that light through a lens (losing 5-10% of the energy) onto your hand and you will be in a world of pain.

Nothing increases. What you are getting is focus.
___________________________________________

OK... you know where the earth is , and its distance from the sun.

now build a imaginary "hollow sphere that big"
the sun in its center.
.......I inserted this today ..........
the distance from the inside surface of the sphere to the sun the being the same distance as the earth to the sun. this distance varries so
you can use 96 million miles as the radius of the sphere in your spreadsheet to find the surface area of the inside surface of the sphere.

using a 2 inch dia magnifying glass at a distance of apx 3 inches I can focus the suns light on an area apx 1/8 inch this morning.

now back up 3 inches from the 96 million miles and find that area where all the magnifying glasses will be placed.

divide that area by the area of the magnifying glass to find the number of magnifying glasses
to use.

then multiply that number by the 1/8 inch area and you will have your heated area on the sphere.
.......... end insert ...................

insert everyone that ever existed and billions more standing on the inside surface of this sphere.

let them do the same " hold a magnifying glass and point it at their hand"

then measure the total area that is being heated
in all the hands...

what would the total heated area be?
more than the surface area of the sun?
if not remove the people and keep only the magnifying glasses and the sphere.
except add a few hundred thousand billion more magnifying glasses to focus the suns light energy onto the spheres inside surface...

now is it bigger?

now with the(losing 5-10% of the energy) loss you speak of how much heat (energy) do we now have?

how much did we begin with?
---------------------------------------
was there any type of increase?
---------------------------------------
was there any type of energy used other than the suns energy?

Im still waiting for your reply...

mostly your right here. but things like splitting any body rather than anybody is more for emphasis. perhaps i should have used "any body" instead. i try to use the spell checker, but sometimes get ahead of myself and don't.

Perhaps Dr. Barr is correct. Perhaps the issue here is your inability to communicate what you mean. But the way it comes off to me is willful ignorance.