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

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

Laser/Water.....need advice please.

N

New Guy

0
Joined
May 3, 2010
Messages
9
Points
0
I'm new, what kind of laser reflects off water best? I am trying to reflect( not refract) one off water and detect the reflection. There is more to it, but that is the main question.
 





I'm not sure which one reflects the best, but I can tell you if you post the same thread in two sections it's considered spamming, and you will get talked at :p. So just don't post the same thread twice again.
 
You can ask a moderator to remove two of them.

Chuck
 
Last edited:
I cant find it. So, sorry to everyone, I thought these were different rooms and all 3 would not be seen by the same group of people. Wont happen again.
However, the question still stands, I need to bounce a laser off water with enough reflection to get a reading. Any ideas?
 
New member here, I've been steered to this thread from a previous post I made earlier, but don't worry, I'm more passing through with a query rather than discussing lasers in depth as electronics are not my field of interest or expertise. My query is purely curiosity.

I was wondering if anyone here is familiar with the concept of lasers as used in the detection of metallic colloids in solution? I have one specific question to which I am failing to find an adequate answer to elsewhere and considered someone here may be familiar with the abovementioned concept.

My query refers to low battery reserve in a laser and what would I expect to observe?

Can anyone tell me how laser light can pass through a container of liquid, spots on the wall on exiting that container of liquid, but FAILS to backscatter light off particles present in that liquid. Is it possible or conceivable that battery reserve is below some operational threshold which may change the wavelength characteristics thus failing to backscatter light due to particles being too small for that rated wavelength of the laser to pick up?

You'll have to excuse my ignorance in terminologies as well.

Thank You.
 
strange that you were linked to this thread.....

Hear-say is that diode lasers can vary by as much as a whole nanometer depending on temperature and/or operating current. I doubt this would affect its usefulness in your case. Could it be something as simple as low battery that leads to drop in output? a less powerful laser will still reflect some light back off the suspended particles, it will be harder to observe.

if this device isn't wavelength dependent (you'd know more than I), you could try using a different laser. Green is easier to see for humans.
 
Thanks bshanahan.

Yes, I'm probly still not in the right place so I won't take up any more time.

This may be more science related praps.

A final question if I may...Can you tell me what I would expect to observe in the operational function of a laser if batteries are draining? Do they still work and spot on a wall, but with far less brilliance or intensity, and with a diminished 'sparkle' to that spot? Do they simply NOT operate at all? {they either emit light or don't emit light AT ALL, if you get my drift}.

If there is a particular current or power threshold for a laser diode to function properly, and battery power falls below that current threshold, does the diode just behave as an ordinary torchlight bulb? {still spots on a wall but fails to function as a laser beam, again, if you get my drift}

Thanks again.
 
It depends on what kind of driver you're using in the laser. I think boost drivers have a cut off current, so they will operate at almost the same power until the batteries die. If you're using a linear driver, like in green lasers, the laser will decrease in power with the batteries. That is my basic understanding of it from what I've heard here. Somebody correct me if I'm wrong.
 
Thanks Kevin.

I should have said earlier I suppose that I am not familiar with high tech equipment and am only referring to your everyday lasers.

Your snipped quote:
[...laser will decrease in power with the batteries.]
-OK, I'll run with this part for a moment. It sounds like it could be fair to say that if battery reserve drops, the strength of laser output [or brilliance and/or intensity if you like} drops accordingly until praps a point is reached whereby the laser fails to function at all. Would this assumption be feasable?

In the eventuality that this assumption is correct, would that then mean the rated wavelength for that particular laser would drop also...ie; initial 650nm may drop to 600, and then keep on dropping in nm wavelength as battery drains until the diode fails to emit light at all?

I may be on the way here in solving one of my quandaries regarding laser operation if any of the above holds any credibility.
 
Yes, the battery will decrease, and the power will decrease till it's dead. That's how most everyday lasers are. No, the wavelength will not change.
 
Ok, Thanks for that.

Just on a final note:
On comparing Tyndall cone in solutions with other lasers I use, I suspect this particular laser may be operating at slightly higher wavelength than stated on the label, not by much praps, but enough to affect backscatter.

Thanks again.

Cheers.
 
Sounds like you're working with some fun stuff!

I will say that below a certain current, the laser diode will cease to lase. It still produces light, but I don't know if you'd be able to project that light too well. It may very well just be weak batteries. I don't think the wavelength of a diode can change so much that it would affect how light scatters off of molecules noticeably.

I have a violet laser on a generic boost driver, and when the batteries start going low, the laser starts pulsing. I don't know if this is a design of the circuit, or if it is a side effect of low power on a boost circuit, though.
 
You must log in or register to reply here.





Back
Top