Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



Laser Pointer Store

Aloha!

KaneHau

New member
Joined
Jan 11, 2007
Messages
12
Points
0
Aloha All...

As a "years old" LASER and LED junkie... let me just say it is a welcome relief to find this forum.

I have had, and loved, lasers from the first day they came out (yes, I remember even the old RUBY lasers). YEARS ago... my first science fair project was a HeNe laser - it was 'novel' because it had brewster windows (oh wow - hello guys, we're talking 40 years ago). Currently I'm on vacation in New Zealand - with my green laser (wish it was a 'wicked laser' :)

Though I've worked for numerious companies in the past (NASA, Truevsion, etc)... currently I work for Subaru Telescope (www.naoj.org)  on the Big Island of Hawai'i - the largest single mirror telescope in the world.  We use ADAPTIVE OPTICS which incorporates artificial laser stars to clean the image....

Let me explain...

Our most recent system (which is just now being deployed) allows us to 'clean up the astronomy image'
by either focasing on a real star (which may, or may not be where we want it to be) or on an artificial star (when the 'guide star' is NOT where we want it to be) which is generated by a laser.

At the summit of Mauna Kea, on the Big Island of Hawai'i (at 14,796 ft) there are many observatories (12, going on 13)... a number of which use lasers and adaptive optic systems, to improve the image quality (we can achieve near hubble quality with this technique).

Our system, which is the very latest - uses a sodium ion laser (beautiful orange/yellow beam - sorry, don't know the manufacturer as this particular unit is temporary until our more powerful real unit is delivered).

When a 'guide star' is not where we want it to be for observing, we project an artificial star using the sodium ion laser.  The reflected beam is fed into an EXTREMLEY expensive photodiode detector system (each detector is over $1000, and there are 188 of them) and the results are viewed by 3 real-time computers.

In realtime we look at the distortion field of the beam, invert it (via some really fancy math, which I don't even understand (though we implement it) - it is not just a simple inversion) and we deform mirrors (a deformable mirror system - EXTREMELY expensive and very very very very cool - think about an 8 inch mirror which has 188 actuators which can deform the various sections of the mirror at the rate of up to 4000 hz per segment - e.g., 4000 times per second per segment - and you can't possible believe how reflective this mirror is - I'm used to laser mirrors and this mirror is as 'near perfect' as I've ever seen) to compensate for the atmospheric distortions that are revealed by the laser (or guide star in the case of a good guide star in the right spot for the desired observation).

This takes out the atmospheric distortion caused by the water vaper layers between the telescope and the target.

In the long run, this gives us one bitch'n image (very stable, very clean - the summit itself is one of the darkest places on the planet - 2500 miles from land in ALL DIRECTIONS - so the laser makes it even more so, and ALL streetlights on the Big Island have special filters on them which we can 'filter out' of the final images - so that the ambient light of the island itself doesn't affect our images).

Anyway... as I mentioned, many of the observatories (Keck, Caltech, etc) use adaptive optics similar (but not as advanced as the current one we are deploying) as ours.

One of the interesting facts is that the beams from the various observatories must be coordinated.  Not only against air traffic, but against each observatory (or the beam might interfere with other observations). There is an unbelivably complex system in place to make sure that beams to not cross beams (yes, this sounds like ghostbusters, DON'T CROSS THE BEAMS - but it is in fact true) and to check for air traffic.  The system involves computer coordination (which includes a human element which requires us to 'request permission to beam') as well as live human 'spotters' which use IR goggles (as each observatory uses different lasers) to spot for the lasers and also for aircraft which may stray into the area. We're talking about 14,976 feet, in Hawai'i, which believe it or not, we have MUCH SNOW (poor spotters... brrrrrrrr).

Anyway, just to share... and to say GREAT FORUM - thanks!

Aloha!
 

S

SenKat

Guest
WOW !  Welcome !  And, as with everyone else - you DO have permission to beam !   Quite impressive introduction, Muhalo ! (hope I did not butcher that too bad !)

Not sure exactly how I posted this in the wrong area when I was replying earlier...verrrrry odd. Anywho, glad to have you !
 

BeautySoulQueen

New member
Joined
Jun 21, 2006
Messages
192
Points
0
welcome!!!
as i said b4....here u can lay under the beam of a laser n catch a tan.....
just like in hawaii :D
 

NairB

New member
Joined
Nov 3, 2006
Messages
175
Points
0
:eek:

Wow KaneHau, welcome to LPF. A very impressive job you have there. :eek:

You must post some pictures if you can of the observatory and if possible that laser system you are using :D

Do you operate/maintain the laser system then? If so can you tell us more what type it is etc ;)

Look forward to some more of your post and...oh...if you need help regarding "normal" lasers, well thats why we are here LOL. ;) ;)
 

KaneHau

New member
Joined
Jan 11, 2007
Messages
12
Points
0
Aloha NairB:

You can find information on the observatory at their official website at:

http://www.naoj.org

I also run a website about Hawai'i and we have a page on the observatory with more info and photos at...

http://instanthawaii.com/cgi-bin/hawaii?Astronomy.anatomy

As per photos of the laser system - I'm currently on vacation in New Zealand but wil check with Subaru when I return to find out the copyright status of the laser photos (there are some stunning timelapse photos of the laser projection testing at night).

As per your questions on my job - I am a computer scientist and am involved in a number of projects. I was on the adaptive optics team for a portion of time and did some of the software which handled the realtime data. Mostly my job involves what we term the Subaru Telemetry
 

NairB

New member
Joined
Nov 3, 2006
Messages
175
Points
0
:D

KaneHau, very, very impressive indeed.

I understand about the sensitivity of the laser equipment regarding copyright......would love to see photo's of the laser unit itself etc and of course any snaps of that wonderful orange beam if possible. :eek:

Maybe you can post the photo with a big copyright sign with your company name over it to protect it. ;) ;)

I looked through your web pages and the photo's the telescope is taking are truly stunning, breathtaking in fact and you are very lucky to be working in this environment.

It's a pleasure to have you on the forum ;)

Look foward to those copyrighted photos of the laser *cough, cough* lol ;D
 

Ragnarok

New member
Joined
Nov 10, 2006
Messages
155
Points
0
Interesting work you do! I found an article online about the guide star/adaptive optics.

Is the laser an actual sodium ion laser or a solid-state laser that produces the equivalent sodium wavelength? The reason I'm asking is that I don't know of a sodium laser, but I see references to dye and solid-state lasers being used to make guide stars by exciting sodium atoms in the upper atmosphere.

Snipped from an online article :

"Diode-pumped sum frequency laser. Left: Two mode locked Nd:YAG lasers, one tuned to 1.064µm and the other to 1.319µm, are mixed in non-linear crystals to generate light at the sodium D2 line (0.589µm)."
 

troyboy

New member
Joined
Jan 23, 2007
Messages
109
Points
0
HEY KANEHOU! just thought it would be fun to tell you the me and sniper and both from hawaii too! lol if we ever sell to each other the shipping shouldn't be too bad! ;)

See ya round!

Aloooooooooooha!
 

Beefygt

New member
Joined
Jan 24, 2007
Messages
153
Points
0
That is fascinating that you use an ornge laser to make an artifucal star. It must be beautiful out there with no city lights bogging down the night sky.

I go to Canada once every year, and I can't wate to go up there with my lasers. I know I will be able to see for miles with it up there. ;D

Anyway, that is also an awesome job you have out there. I would love to have a job like that looking up at the night sky. ::)
 
L

laser

Guest
here in hawaii (yes i live there too, so does troyboy and sniper) the humidity in the air makes the laser beam really visible. plus, theres no light pollution, or anything. when it rains, i immidialty grab my laser, because it looks so cool!!

anyways...that makes 4 people from hawaii...i think..
 




Top