Quiz Me

[BShanahan14rulz]

Explain how quantum photon entanglement contributes to the frequency doubling process in a 532nm laser. I'd like to know this one too :eg:

 

[Misanthrop]

Explain how quantum photon entanglement contributes to the frequency doubling process in a 532nm laser. I'd like to know this one too :eg:

ftp://ftp.cordis.europa.eu/pub/ist/docs/fet/qip2-eu-08.pdf

read this.


Edit: IF YOU DARE !

 

[robertkoa]

If I play around with a 5 to 10 mw green laser with no goggles and a reflection off a metal doorknob or a window pane reflects back at me at about 10 feet away ( 20 foot round trip ) about what % percentage of original beam power hits my eye ?

Question 2 - is a verified 5 mw with an IR filter the only way to be safe in this instance ?

 

[Misanthrop]

If I play around with a 5 to 10 mw green laser with no goggles and a reflection off a metal doorknob or a window pane reflects back at me at about 10 feet away ( 20 foot round trip ) about what % percentage of original beam power hits my eye ?

Question 2 - is a verified 5 mw with an IR filter the only way to be safe in this instance ?

Are you trying to pass off a real life situation that just happened to you, as a question? lol

 

[robertkoa]

Are you trying to pass off a real life situation that just happened to you, as a question? lol

No - I'm trying to assess what power Laser I can safely play with without goggles, and will probably order a 30 mw rechargeable ( not a pen ) or 2 and have someone mod it down to 5 or 10 mw, verified on meter and IR filter, and they get to keep the 2nd one.

So I'm asking how low do I go ?

My 'Laser Experience' is limited to a VERY sophisticated LED Flashlight with red laser pointer from Auto Store- these are over $7.00 and should only be purchased by the most EXPERT Laser Users on this Forum who fully understand a two way LED/Laser combo with a 3 mw red laser.........

 

[Ash]

No - I'm trying to assess what power Laser I can safely play with without goggles, and will probably order a 30 mw rechargeable ( not a pen ) or 2 and have someone mod it down to 5 or 10 mw, verified on meter and IR filter, and they get to keep the 2nd one.

So I'm asking how low do I go ?

<5mW is the only way to be safe 1mW would be safer if you are going to "play" around with it without glasses. I would just order a 1mW from here and ask them to install an IR filter.

My 'Laser Experience' is limited to a VERY sophisticated LED Flashlight with red laser pointer from Auto Store- these are over $7.00 and should only be purchased by the most EXPERT Laser Users on this Forum who fully understand a two way LED/Laser combo with a 3 mw red laser.........

Wow. This comment is truly at the height of facetiousness. Are you sure you are not a professional stand-up comedian? :crackup:

 

[Misanthrop]

my 'laser experience' is limited to a very sophisticated led flashlight with red laser pointer from auto store- these are over $7.00 and should only be purchased by the most expert laser users on this forum who fully understand a two way led/laser combo with a 3 mw red laser.........

not sure if rep or joke

 

[Guyfromhe]

not sure if rep or joke

Sounds like a joke... excellent!

 

[lasersbee]

Yeah.... I think that Post #69 needs some smilies to
convey the sentiment....

Jerry

 

[robertkoa]

<5mW is the only way to be safe 1mW would be safer if you are going to "play" around with it without glasses. I would just order a 1mW from here and ask them to install an IR filter.

Wow. This comment is truly at the height of facetiousness. Are you sure you are not a professional stand-up comedian? :crackup:[/QUOTE

1 mw will look like a green dot at the end of the lens that doesn't go anywhere- has to be at least 5 mw.

The Op never answered my question either, did he ?

OK one guy is on a motorcycle headed East at 120 mph with a Violet Laser on his handlebars-

Re: post # 69- .........per Forum rule # 467 and because most of you have vast expertise on the subject- it was deemed that smiley face not necessary- no disrespect intended of course and your expertise on this Forum is REAL and respected , - not a sarcastic comment about your expertise, more about my silly little flashlight Laser.

Who was the inventor of L.A.S.E.R. ? And when was the device/acronym created ?

ANOTHER motorcyclist is heading west at 120 mph with a Red Laser on his handlebars...........

 

[MegaWattson]

I'm back.

About the coconuts...I posted first. Nyah nyah nyah.

About the Fabry-Perot etalon...Ouch. I think I just sprained my brain. Good thing about getting older, I can blame it for not remembering the details on something I read in the last few months. But I would like a refresher if you might be bothered.

I think I hear the boss coming...

Yep, ya got me on the coconuts.:scowl:

Regarding the etalon, I was kinda hoping Gofilord would do some research and take a stab at an answer.

Anyway, the finesse of a Fabry-Perot etalon is a measure of it's resolution. That is, it's ability to resolve closely spaced lines within it's resonant cavity. It's important because this is what determines the practical limit of the cavity's line-narrowing ability. There is also a direct correlation of finesse for Fabry-Perot interferometers used in spectroscopy.

You might want to read up on Fabry-Perot etalons and interferometers. They are extremely significant in the world of lasers, and a really interesting topic in their own right. The principles on which they operate are the same as those for many laser cavities and even multilayer thin-films. In fact, most of the laser types in use today are based on the Fabry-Perot resonator. This, despite the fact that it's design pre-dates the invention of the laser by more than a half-century! They are deceptively simple devices, and I think it's this elegant simplicity that I find most appealing.

Take the basic ruby laser, for example. It's a classic Fabry-Perot resonator cavity. And it's that cavity that is responsible for the monochromaticity of the laser's output. In other words, the emission spectra of the main lasing transitions for the ruby as a gain medium are fairly broad (with a bandwidth on the order of 0.5 nm), while the bandwidth of a typical single longitudinal mode is on the order of 0.00005nm. It is the physical form and dimensions of the cavity that are responsible for selecting those modes which will become the output beam. The other modes are presented with a cavity of diminished Q factor (for their λ/2 integer multiple), and therefor are not sustained.

If you want to mess around with the concepts behind it, you can make crude (but functional) Fabry-Perot interferometer with just a few components and a stable base. :thinking: Mechanical and thermal stability are key here, as is the homogeneity of your cavity medium (most likely air), so if you try this, stay clear of heating and A/C air vents.

Have fun! :yh:

-mega

 

[AJ Pierson]

Yep, ya got me on the coconuts.:scowl:

Regarding the etalon, I was kinda hoping Gofilord would do some research and take a stab at an answer.

Anyway, the finesse of a Fabry-Perot etalon is a measure of it's resolution. That is, it's ability to resolve closely spaced lines within it's resonant cavity. It's important because this is what determines the practical limit of the cavity's line-narrowing ability. There is also a direct correlation of finesse for Fabry-Perot interferometers used in spectroscopy.

You might want to read up on Fabry-Perot etalons and interferometers. They are extremely significant in the world of lasers, and a really interesting topic in their own right. The principles on which they operate are the same as those for many laser cavities and even multilayer thin-films. In fact, most of the laser types in use today are based on the Fabry-Perot resonator. This, despite the fact that it's design pre-dates the invention of the laser by more than a half-century! They are deceptively simple devices, and I think it's this elegant simplicity that I find most appealing.

Take the basic ruby laser, for example. It's a classic Fabry-Perot resonator cavity. And it's that cavity that is responsible for the monochromaticity of the laser's output. In other words, the emission spectra of the main lasing transitions for the ruby as a gain medium are fairly broad (with a bandwidth on the order of 0.5 nm), while the bandwidth of a typical single longitudinal mode is on the order of 0.00005nm. It is the physical form and dimensions of the cavity that are responsible for selecting those modes which will become the output beam. The other modes are presented with a cavity of diminished Q factor (for their λ/2 integer multiple), and therefor are not sustained.

If you want to mess around with the concepts behind it, you can make crude (but functional) Fabry-Perot interferometer with just a few components and a stable base. :thinking: Mechanical and thermal stability are key here, as is the homogeneity of your cavity medium (most likely air), so if you try this, stay clear of heating and A/C air vents.

Have fun! :yh:

-mega

Hey that sounds like a good project. Thx for the info mega.

What kind of optics do we need to make one of those? And what kind of laser is best for it? I have some lenses and mirrors around here, but I don't know how to make a "cavity", exactly? know what i mean?

plz lmk , and +1 rep from me.

 

[ShortyInCanada]

That is where I came across it !
I was reading up on solid material laser systems and some of the really old stuff.
Started looking into it all as I had easy access to an old ruby rod and was trying to figure out if it would be practical to try to turn it into a rudimentary home made laser. But the optics part did me in. I had an idea about using multiple zenon strobe type flash tubes as optical pumps in a mylar reflector with the ruby rod at the focus of it all...having multiple strobes all firing as fast as possible in a contained system...all that high voltage...makes my skin tingle just thinking about it ! Oooooooooooo
But getting the proper mirrors and manufacturing solid mounts for it all and keeping my young son out of it all...maybe some other time.

Many thanks for filling in some more info though. I think some more might be sticking in my brain too.
:thanks:

 

[MegaWattson]

My 'Laser Experience' is limited to a VERY sophisticated LED Flashlight with red laser pointer from Auto Store- these are over $7.00 and should only be purchased by the most EXPERT Laser Users on this Forum who fully understand a two way LED/Laser combo with a 3 mw red laser.........

I was just cruising back through this thread to see if I missed any good questions, and I noticed this.

That's the funniest damned thing I've read all week! Thanks man! Nice job with the dry wit...

I actually saw some of those combination LED/Laser diode units at Home Depot, and I was tempted, but I decided that I needed to do some research to learn how to safely handle that type of system before making the purchase. Safety is paramount at this level of hardware......Well, maybe someday...:crackup:

"I'm sorry I can't do that Dave."

"Open the door, HAL."

Can you believe that flick is over 40 years old? Still epic, after all these years. Now I just gotta dig it out and watch it again.....


-mega