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

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

optical head with plexiglass frame

Joined
Mar 18, 2012
Messages
173
Points
0
Ah so the modules won't be tightly seated against the heat sink then. This method will work but has it's obvious downfalls.....anyway it looks pretty cool so kudos to you :beer:

Many thanks. :beer:
You are referring to the thermal continuity... over the modules there is a custom made thermal compound made of a thermal paste mixed and saturated with chemical aluminum powder so there is an optimal thermal continuity between modules and the heatsink. This thermal contact is even better than a simply mechanical contact because it extends over all the surfaces and not only the mechanical seating surface.
 
Last edited:





Joined
Mar 18, 2012
Messages
173
Points
0
Ill bet the plex will give off a nice glow when its running.

You are right, the plexiglass is glowing with the scattered light.
I will post other photos when completed the final electrical connections and the beams alignment
 
Last edited:
Joined
May 10, 2009
Messages
379
Points
28
Many thanks. :beer:
You are referring to the thermal continuity... over the modules there is a custom made thermal compound made of a thermal paste mixed and saturated with chemical aluminum powder so there is an optimal thermal continuity between modules and the heatsink. This thermal contact is even better than a simply mechanical contact because it extends over all the surfaces and not only the mechanical seating surface.

Well that was one of the potential issues with that method....i guess if the gap is minimal, but then adjustment is limited....
One other potential issue is de-alignment due to thermal expansion (creep). Adjustment via set screws in that type of configuration is often seseptable to this because of slight variations in temperature between the module, set screws and heat sink. If relatively moderate output diodes or conservative input currents are used, along with short duty cycles you most likely won't have any issues. However even the slightest movement will result in far field misalignment.
Just something to be aware of, you probably already know....
 
Joined
Mar 18, 2012
Messages
173
Points
0
Well that was one of the potential issues with that method....i guess if the gap is minimal, but then adjustment is limited....
One other potential issue is de-alignment due to thermal expansion (creep). Adjustment via set screws in that type of configuration is often seseptable to this because of slight variations in temperature between the module, set screws and heat sink. If relatively moderate output diodes or conservative input currents are used, along with short duty cycles you most likely won't have any issues. However even the slightest movement will result in far field misalignment.
Just something to be aware of, you probably already know....

Many thanks for your informations. I have observed the problems you are speaking about.
You are absolutely right, the thermal stress produces misalignment and the heat produced by the two diodes is very high (at 4.7Vf each and 1.8A, we have 17W, 4.5-5W of light and 12W of heat...).
The optical head has no problems because it's thermally isolated by the heatsink with nylon screws and spacers.
I think also that using conservative input currents or short duty cycles is wrong, because we are trying to maximize efficiency to maximize run time and we are pushing the diodes to their limits to get more power. If i need to limit the use i would prefer to use one diode only pushed to it's limits with no alignment problems...
A smart solution is probably the use two very short, polarization-maintaining fiber optics to couple the diodes with the optical head leaving the diodes free to move with heat and the user happy to use the hand-held for a long time with high power... but this solution could be costly and also increase the size...
What do you think? Do you agree? Any suggestion for the fiber we could use?
-Luke

edit: the diode-fiber coupling efficiency could be a problem...

attachment.php


attachment.php


attachment.php


attachment.php
 

Attachments

  • img1.jpg
    img1.jpg
    84.7 KB · Views: 535
  • img2.jpg
    img2.jpg
    74.2 KB · Views: 503
  • img3.jpg
    img3.jpg
    77.9 KB · Views: 487
  • img4.jpg
    img4.jpg
    75.1 KB · Views: 492
Last edited:

AnthoT

0
Joined
Jan 14, 2012
Messages
2,133
Points
48
Ok that is the sickest thing I've seen :drool:

The fibers sounds like a good idea, or maybe just use the same material for the set screw heatsink & module. :D
 
Joined
Mar 18, 2012
Messages
173
Points
0
Ok that is the sickest thing I've seen :drool:

The fibers sounds like a good idea, or maybe just use the same material for the set screw heatsink & module. :D

It's a very monster... it burns almost instantly a white sheet of paper at 40cm and you must use the goggles because the brightness is terrible :yh:
Obtaining a good alignment it's a nightmare... Ramsey is right...
 
Last edited:

AnthoT

0
Joined
Jan 14, 2012
Messages
2,133
Points
48
It's a very monster... it burns almost instantly a white sheet of paper at 40cm and you must use the goggles because the brightness is terrible :yh:
Obtaining a good alignment it's a nightmare... Ramsey is right...

Yeah... Well once you got that alignment it looks amazing though... :)
 
Joined
Feb 10, 2012
Messages
330
Points
0
What a beauty, an electronic - mechanical - optical, delight.

I look forward to reading you posts and updates.
ATB
MM
 
Joined
May 10, 2009
Messages
379
Points
28
As fas as fibre coupling goes, I have not personally done this for combining but in our applications it would likely reduce efficiency due to the added necessary optics for collimating. There is a gentleman local to me who is a leading expert on combining. His preferred method is to fibre couple and combine via volume bragg gradings. Of course this comes with a hefty price tag and can be complicated to design, not to mention the laser's wavelength must be very stable and without active temperature control that can be hard to achieve. The pay off though is very high efficiency and damage threshold.
In my opinion, for our purposes I would suggest taking at look at how most labs and professional projectors achieve beam combining. The laser is in a fixed position and well heat sunk and the optics are adjustable....not the other way around....
Because my company does have a patent pending on a combiner module it is in my best interest to not go any further into detail about configurations, optics etc.... I'm sure you can understand. Unfortunately production of the module has hit some bumps in the road and things in my life (ie. Kids and work) have forced me to put this on hold several times. The good news is I'm past the hold ups and I'm back to production....
Best of luck to you on your endeavours, your work looks very good, keep it up! :beer:
 
Joined
Mar 18, 2012
Messages
173
Points
0
As fas as fibre coupling goes, I have not personally done this for combining but in our applications it would likely reduce efficiency due to the added necessary optics for collimating. There is a gentleman local to me who is a leading expert on combining. His preferred method is to fibre couple and combine via volume bragg gradings. Of course this comes with a hefty price tag and can be complicated to design, not to mention the laser's wavelength must be very stable and without active temperature control that can be hard to achieve. The pay off though is very high efficiency and damage threshold.
In my opinion, for our purposes I would suggest taking at look at how most labs and professional projectors achieve beam combining. The laser is in a fixed position and well heat sunk and the optics are adjustable....not the other way around....
Because my company does have a patent pending on a combiner module it is in my best interest to not go any further into detail about configurations, optics etc.... I'm sure you can understand. Unfortunately production of the module has hit some bumps in the road and things in my life (ie. Kids and work) have forced me to put this on hold several times. The good news is I'm past the hold ups and I'm back to production....
Best of luck to you on your endeavours, your work looks very good, keep it up! :beer:

Sincerely thanks.
This is for me an hobby because i work at the university on different arguments. This hobby is sometime costly in several ways (i have two kids and a very tolerant wife :) ) so it is nice to receive a compliment.
Best of luck to your life, it was nice to meet you :beer:
 
Joined
May 10, 2009
Messages
379
Points
28
Ah it seems we have a quite a bit in common then.... I have two boys and a very supportive and understanding wife as well. Yes compliments can go a long way, helps to motivate future work.
Now that we are official friends here, you can take a look at my private album. There you will find several pics of the prototypes I've made prior to designing the production model. Just a sneak peak though...
 
Joined
Mar 18, 2012
Messages
173
Points
0
Ah it seems we have a quite a bit in common then.... I have two boys and a very supportive and understanding wife as well. Yes compliments can go a long way, helps to motivate future work.
Now that we are official friends here, you can take a look at my private album. There you will find several pics of the prototypes I've made prior to designing the production model. Just a sneak peak though...

Very nice collection with special care for the design :gj:
However i must say that the best design is shown in the photo named "best friends" :)
 
Last edited:
Joined
May 10, 2009
Messages
379
Points
28
Thank you very much for the compliments! They truly are best friends, James has grown so fast and now my youngest, Anthony is already the same age as James was in that pic.....wow time flies!!!
 




Top