fiber optic beam combining

[catalanjo]

... it's not so hard to ........., but with attached tweezers or other manipulators for all sorts of "manipulating" small objects with high precision..........When building the assembly-stages for fiberscopes and micro-sensors, I've made some micro-positioners/manipulators with 4, 5 or 6 axes per block and sometimes 2 to 3 aditional axes as base for combining this-blocks to multiaxis modules for handling multiple fibers, lenses or electronic parts ...Viktor

Keep the pics rolling thru Viktor ........I would love to see one of your multiblock/multiaxis/multiparameter setups...there is definitely as much Art as Science in many of these types of gizmos, and although it may seem that Mr.P keeps blowing you out of the water, ...... his own super simplified "cut to the chase" spatial filter is a typical example of this kitchen table style of creativity!

Once you have "whatever it is" in the right place, with the right poise and attitude, what techniques do you usually use to "fix" it there?

Cheers.

[planters]

although it may seem that Mr.P keeps blowing you out of the water,

I am not trying to rain on anyone's parade. A FAC corrected diode is achievable and with the right equipment, including a manipulator and a microscope to see what you are doing, they can be assembled and function well. However, if the only reason is to reduce the size of the optics needed to collimate a diode then applying the same level of precision that is needed to build a FAC will likely produce a better beam with macroscopic optics.

[VDX]

...
Once you have "whatever it is" in the right place, with the right poise and attitude, what techniques do you usually use to "fix" it there?

... this depends -- sometimes 2K or UV-curing adhesive, sometimes preparing with solder or other melting coating and then solder/braze/fuse it with laser, somtimes clamping or screwing ... or complete different


For handling -- here are some videos of "simple 3-axis setups":

- micro-montage demonstration of fiberscope optics (diameter of optical fiber and GRIN-lens = 0.35mm) - https://vimeo.com/12275357

- positioning gears with the same setup (diameter of sticks/axes = 0.3mm) - https://vimeo.com/173369900

- buildup-demonstration of the used setup with cameras, light and 3-axis-micropositioner on a magnetic plate - https://vimeo.com/173369901

The +5-axis setups were variyng in types and handling -- some designed for manual manipulation or smallest possible footprint, others (with motors or micro-/nano-positioners) for tele-operation ...

Viktor

[catalanjo]

Thanks for links Viktor!
@ 2k = ???? "glue" of somekind ? .... (UV curing I use already = very sunny here in Spain)

@"not raining on parade" ...yeah I know, ..... your opinion is highly valued, & will probably save me yonks of work & frustration.

However I have this "curiosity" ....(problem ? )

Cheers

[VDX]

@ 2k = ???? "glue" of somekind ?

2K stands for "2 components" - http://www.uhu.com/en/products/epoxy...component.html

You mix small amounts of the two compounds and have to wait some ten minutes to hours (fast or slow curing types) until it fastens.

UV-curing glues cures/hardens instantly if illuminated with UV light - I'm mostly using high power 405nm-LED's -- and the glue is solid in some seconds

Viktor

[catalanjo]

Yeah I spose I should have guessed that!
I was vaguely hoping for some kind of special glue I had never heard of !
Cheers

[kecked]

I took a .5mm glass rod and tried to use a manipulator used to wire bond and position the rod. My back still hurts from the nearly 2 hour ordeal. Result yes it does work but what a pain in the ass. I then bumped the table before glue so I quit. Oh and this rod was suppose to be super polished and surfaced and parallel. At first I tried glass fibers. That was a joke. Without a really purpose made device and purpose made rod and profile reading detector it isn't going to work. I have to say after a couple of weeks. Yes weeks of trying different things. Planters method is by far the easiest and best result.

We owe him a lot for sharing that method. I should add I killed 6 diodes trying this.

[planters]

If you are a little adventurous and want an extremely high quality beam you might look at this paper. Google "diode pumped dye laser" (I can't link to this paper from 1993 by Scheps, but you can open the PDF and look at it). Green diodes should be able to pump rhodamine for red to yellow and the blue diodes should be able to pump the coumarins for cyan. The conversion efficiency is very high, they are CW and modulation of the diode pump will modulate the dye. The exposed jet could be replaced by an enclosed cuvette. The author applied for a patent.

[mixedgas]

If you want to do that, you really want to read:
!
Diode-pumped dye laser analysis and design
!
D. P. Benfey, D. C. Brown, S. J. Davis, L. G. Piper, and R. F. Foutter
!
Basically the design limitation is how fine a spot you can focus the 514 nm diode to... You then need to mode match the beam diameter in the resonator to the spot size at the dye jet...
!
Benfey at al, covers how to do that..
!
I have a friend that used a small DPSS to threshold a Coherent ring dye laser, he needed 1 watt of 532 nm light to get a few hundred microwatts of dye light.. He could not threshold a cuvette due to the triplet state problem. I spent many hours helping him, and we had to change the high power OC to a low transmission optic from my collection.
!
Steve

[catalanjo]

@ kecked ..... bummer about the diodes ...how did that happen?

@ Mr P = Thanks for link and like I said earlier concerning "not raining on parade" ...yeah I know, ..... your opinion is highly valued, & will probably save me yonks of work & frustration" ...seems like kecked has just confirmed that one beyong shadow of doubt.

@ Steve = also thanks for links.
I am having a bit of problem finding cheap source of different optics for my Coherent dye laser, but if I get some success I will certainly try this. Although I agree the spot size is a HUGE problem and I was also going to try it (with a Viasho 7w DPSS) @532 not a 514 diode !
Cheers
The advantage of the exposed jet is that it avoids (or reduces) boiling in the dye.