Optical Trapping - Real Laser Tractor Beams

[ossumguywill]

I tried it with a different laser, pretty damn cool! BTW this laser diode lens was not as clean, so maybe a dirtier beam=more traction LOL

 

[bhank]

Old thread I know lol but I thought of this thread while I was burning and cutting matches with my 445 set at 920mA a few minutes ago. Seems to work pretty well and because I like blue a lot more than red, I thought it was amazing having a blue "tractor beam" in my hand haha. I don't have the ability to get a good quality video of it but someone should post a video of it, it's quite nice

 

[ReNNo]

I noticed that optical trapping is much more difficult with blue laser.

To trap particle you need radial magnetic field, and to get radial magnetic filed you need round beam (TEM00).
And 445nm diodes are multimode and beam is not round.

I think that is reason why 445nm is not that effective for optical trapping as we expected because of high power.

 

[Exerd]

This is a very interesting play of physics in this experiment.

:gj:

 

[bhank]

Hmmm, that could explain why I got it to work a few times but it was pretty unreliable. I posted my last post then tried and it was really difficult to get any particles trapped. The first few times it would only work for about 5 seconds too.

 

[Glitch]

If the experiment is just to trap particles in the beam, then couldn't one simply light a match underneath the beam? Does it have to be an object placed directly in the beam, versus random particles intersecting with it?

 

[aXit]

I would say a match wouldn't work. With a match, there is too much heat coming with the smoke (even if it's blown out) that would create convection currents that would prevent particles getting stuck in the beam. Go ahead and try though.

 

[ppbss]

impressive :drool:

 

[Glitch]

Curious...I remember seeing a YouTube video about a laser experiment which resulted in a stable plasma ball (something something femtosecond laser something something). Could a similar effect be achieved with multiple intersecting lasers, all set with the same focal point?

It would be interesting to see the results of several (if not multiple tens of) beams focused on the same point in space.

I'd always heard that there were experiments done with intersecting beams which resulted in termination of both beams; something to do with polarizing the output. I'm not sure if it's real or not, but it'd be something to try.

 

[cd520]

I've got to say thats quite awesome.

 

[CrazyMonkey]

Tried it with my 445 for the heck of it. Figured it would not work, being multimode.
All I accomplished was setting the felt tip on fire a few times, lol.. The focus was also about 2" out, the closest I can do atm.