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World first high power underwater handheld laser

Podo

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Yesterday we put our latest stainless steel handheld laser underwater to test it and the laser is using a 3W 445nm diode(NDB7875).

We just got back two videos from our scuba diver, the laser seems to function and runs perfectly in 30ft undersea with a magnetic sliding switch, a quite satisfying result to prove the laser can survive such harsh environment.

The next step would probably a endurance test to see how deep it can go without damaging/malfunctioning, please wait for more news updates :eg:

Nevermind the date, the date setting is wrong, please ignore it.

PS. Unfortunately the laser itself is not filmed in both videos, we will sure to do that on the next video.:crackup:


:thanks:
-Sanwu Lasers
 
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BobMc

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Re: World first high power underwater dive laser?

Yesterday we put our latest stainless steel handheld laser underwater to test it and the laser is using a 3W 445nm diode(NDB7875).

We just got back two videos from our scuba diver, the laser seems to function and runs perfectly in 30ft undersea with a magnetic sliding switch, a quite satisfying result to prove the laser can survive such harsh environment.

The next step would probably a endurance test to see how deep it can go without damaging/malfunctioning, please wait for more news updates :eg:

The date setting is outdated, please ignore it.

PS. Unfortunately the laser itself is not filmed in both videos, we will sure to do that on the next video.:crackup:


:thanks:
-Sanwu Lasers
Nice!! now I got to get me a second job!:drool:
 
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Re: World first high power underwater dive laser?

Very cool indeed! But can it burn underwater? Haha jk don't shine it at the fishies!
 
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Re: World first high power underwater dive laser?

Ah man I'm finally getting some income and its perfect timing for all this good stuff coming out!

Is this laser gonna be a brand new model? Or will it be a redone version of one of the current models?
 

Benm

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Looks pretty cool, i bet the water solves a lot of cooling problems down there ;)

One thing i wonder about though: Is blue the ideal color? If you wanted to point things out in deep water would red not be a more suitable color? Obviously the water above you filters out red and green light when deeper, so it would stand out a lot more from the rest of what you are seeing. Range would be lower for red, but how far do you practcially point out things when diving? And it's not even required to hit them with the laser beam at all since you could see the direction it's pointing.
 

Encap

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Looks pretty cool, i bet the water solves a lot of cooling problems down there ;)

One thing i wonder about though: Is blue the ideal color? If you wanted to point things out in deep water would red not be a more suitable color? Obviously the water above you filters out red and green light when deeper, so it would stand out a lot more from the rest of what you are seeing. Range would be lower for red, but how far do you practcially point out things when diving? And it's not even required to hit them with the laser beam at all since you could see the direction it's pointing.

Not exactly. In 1963 a low-loss “optical window” of undersea communication for blue-green lasers between 420–532 nm was discovered. Since then research has not stopped. Blue/green laser light has the best transmissivity through water, however, some systems employ 635nm for underwater use in limited well defined applications with a few types of sensors.

The reasons that there aren't many applications of lasers in an
underwater environment is associated with the way light is transmitted
underwater.

There are two distinct causes for the energy loss of a light signal in seawater:
one is absorption and the other is scattering - 2 separate problems:

A. Most light is absorbed by water -- Water absorbs ultraviolet,
yellow and red and infrared radiation very strongly, so that beams in
these spectral regions cannot be transmitted very far -- meaning that
systems using such lasers are pretty useless. On the other hand, water
(seawater, that is) transmits blue-green light pretty well -- losing
"only" about 5% of its original intensity for every meter it transmits
through water.

B. There are often little specks of dust, tiny animals
(phytoplankton), and tiny plants (photoplankton) in water, and these
reflectd a little bit of the light, too, reducing intensity as it passes
through water. This adds to the problems noted above in Item A.

The effect of these two effects is that lasers used underwater have to be
much more powerful than those used in air, where absorption is generally
much lower than in water.

The above having been said, lasers have been used for underwater applications for quite some time.

One successful use of lasers is a laser system that provides underwater sensing -- a kind of laser radar:
Blue-green lasers located in airplanes are sometimes aimed
so that they go straight down into water that the planes are flying over.
Using very sensitive detectors in the airplane, the system detects the
small amount of light reflected both from the surface of the water and the
bottom of the harbor. This allows measurement of the water depth to
accuracies of a foot or so. The big advantage of such systems is that
they can collect data very quickly, because the airplane moves very
quickly and the lasers can be pulsed at a high rate. One example of this
is the use by Australian government planes of such a system to map their
very large coastal areas -- it's much quicker and cheaper to use a laser
radar to do this than it is to use conventional acoustic (sound wave)
sonars to make such measurements from ships.

Another laser system which is used underwater uses blue-
green lasers to communicate from airplanes to submarines. As early as
1983, experiments were done which demonstrated that this could be done
sucessfully. Investigated successfully also were satellite to submarine communications
using blue-green lasers which not much has been published about for obvious reasons.

Beyond this, there haven't really been too much uses of lasers
underwater. Bob Ballard -- the man who mounted the expeditions that found
the Titanic in the North Atlantic Ocean -- expressed some interest in
trying to use blue-green lasers to assist in taking pictures of the
Titanic, but found out that development of an appropriate system would be
very expensive and not too much better than just using high power
spotlights... which he ultimately used instead of lasers.


For more information see Electromagnetic Absorption by Water here:
https://en.wikipedia.org/wiki/Electromagnetic_absorption_by_water

A more detailed information with great graphics, see: Water absorption spectrum

Technical article: Absorption and attenuation of visible and near-infrared light in water: dependence on
temperature and salinity
here: ftp://misclab.umeoce.maine.edu/users/optics/classFTP2015/Labs/Lab2_resources/Pegauetal1997.pdf

Interesting paper from 1983 on military applications of blue-green lasers:
http://www.google.com/url?url=http://www.publications.drdo.gov.in/ojs/index.php/dsj/article/download/6173/3278&rct=j&frm=1&q=&esrc=s&sa=U&ved=0ahUKEwjYu7OiydHPAhVDPD4KHVCEBVs4ChAWCBowAQ&usg=AFQjCNGGhfUkWXE-TJQjZqO7Y5W_Mr63EQ

Good site on Ocean Optics see: http://www.oceanopticsbook.info/view/overview_of_optical_oceanography/inherent_optical_properties
 
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kaunak

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I'd image that the laser would have a near continuous duty cycle under the water? That's a great advantage of having a purpose-made laser under water; you don't have to worry about heatsinking as much, as the water will act as an excellent heatsink. Awesome laser :)
 

Encap

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1 atm/32ft/10 meters of water resistance is pretty much useless for "diving" however it is great to have a little more water resistance than is normally the case with hand held lasers. Gives a liitle more comfort in using it outdoors in any environment--rain, snow, sleet, hail, mud, camping , climbing, and so on. Would tolerate a lot of environmental situations most hand held lasers don't tolerate well.

A no worry laser for use outdoors in any environment is a good new product idea. Would provide a greater degree of comfort and utility when using outdoors----same as 99% of "dive" watches which are sold to people who never dive or use them underwater---they just like a watch impervious to the environment --just in case.

Would be great to see it offered in any wavlength and output power the other Sanwu lasers are offered in, not just 3W 445nm for the reasons stated above.

If you really want a hand held laser for underwater or diving use, a water resistance standard needs to be identified that is met or exceeded as well as salt water corrosion resistance.

Keep in mind that a water resistant watch is only good for continuous use at 1/10th the rated depth--so rated at 1000m is good for continuous use in the real world at 100m.

Typical classifications for wristwatch water resistance are as follows:
Water Resistant 3 atm or 30 m: Suitable for everyday use. Splash/rain resistant. Not suitable for showering, bathing, swimming, snorkelling, water related work and fishing.
Water Resistant 5 atm or 50 m: Suitable for swimming, white water rafting, non-snorkeling water related work, and fishing. Not suitable for diving.
Water Resistant 10 atm or 100 m: Suitable for recreational surfing, swimming, snorkeling, sailing and water sports. Not suitable for diving.
Water Resistant 20 atm or 200 m: Suitable for professional marine activity, serious surface water sports and skin diving.
Diver's 100 m: Minimum ISO standard (ISO 6425) for scuba diving at depths not suitable for saturation diving.
Diver's 200 m or 300 m: Suitable for scuba diving at depths not suitable for saturation diving.
Diver's 300 m to 1000 m +: suitable for mixed-gas diving.

Would be nice to have availale a real "dive" laser good to 1000 meters depth as many dive watches are good to 1000 meters these days. Is kind of the new modern everyday "dive' watch standard. There are dozens watches on the market that meet or exceed 1000m--many 2000m, 3000m and even several 4000m 13,120 ft water resistant watches tested to 5000m wrist watches on the market these days.
CX Swiss Military came out with a dive watch tested to 7,500 meters in 2009, believe it our not, with an excellent 3 sub-dial, all mechancial, self-winding Valjoux 7750 3 plane cam chronograph movement with date and a pure Ti case. See: http://www.ablogtowatch.com/cx-swiss-military-20000-feet-diver-deepest-diving-mechanical-watch-ever/

Outside of special purpose lasers made for highly specialized military units, for certain well defned operations, I have not heard of any underwater hand held lasers that can be used, even momentarily, at depths greater 200ft. or so.

Laserbtb began offering a hand held laser that is good for 50 meters deep, but highest outputs offered are a 2000mW 445nm model with a 10minutes on/20 seconds off duty cycle and a 520nm with 10 minutes on/ 10 seconds off duty cycle in a 26mm diameter X 19.3cm host, a couple of years ago --see: http://www.laserbtb.com/productshow.asp?id=63
 
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Cel

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Water resistance is one thing, but beware of salt/mineral crystallization if drops of sea water (or hard water) dry out. :)
However there will be no problem washing the laser. :D
 

Encap

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Water resistance is one thing, but beware of salt/mineral crystallization if drops of sea water (or hard water) dry out. :)
However there will be no problem washing the laser. :D

Argee 100% --Important point and consideration---

Any underwater "dive" laser host should be a very low tolerance, tight, high precision threaded 904L stainless steel host to prevent premature deterioration due to chloride/salt exposure which is common with most stainless steels or alternatively made from pure Ti or a Ti/Pd alloy host with solid copper internal module/heat sink. Whenever fresh titanium is exposed to the atmosphere or to any environment containing oxygen, it immediately acquires a thin tenacious film of oxide which provides excellent corrsion protection. Salt water is not easy on materials.
 
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CurtisOliver

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Wow, spear fishing of the future. Goes up to fish, and fires a spear of photons instead. :D Impressive Podo :) +rep
 

Encap

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I think the main issue is safety and rules. If it can operate under water, it will operate in air as well. Then a handheld laser power shall be limited to 5 mW.

Safety is always a paramount issue in sea, air, and land use of lasers--underwater as well.

Excellent point---probably true if someone were to manufacture and sell to the general public as an item of commerce within the United States.

Sanwu is in China and no such Laws, rules, or regulations exist there so anything goes and frequently does there without restriction.
 
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