Preliminary review of O-Like 400mw Green

A more detailed review with photo's, instrumentation measurements etc will follow. I only had a few minutes with the product back in our laser lab this afternoon. Next week, I'll provide more.

Product Reviewed:
400mW green laser torch /focusable/waterproof [OL-532-350] - $214.00 : Welcome to O-Like.com, Your source for laser products
"400mW green laser torch /focusable/waterproof"


Appearance/Aesthetics

The product photo's on O-Like's product page (link above) are very accurate.

While's it's beefier than a typical presentation pointer, it is a sleek device of continuous diameter front to back. The case area approximately over the the laser diode and lens assembly is grooved with very nice fit and finish.

In all, it's a very professional looking product with a sleek appearance that belies a powerful punch.

Functionality


The 18650 is loaded from the rear, with a very nicely threaded endcap. The power cavity is protected by an O-Ring that seems properly sized and placed to exclude incidental submersion.

The device is activated by a continuous on/off switch at the end of the device. The switch seems to be well made. The external portion is made of textured, durable plastic of a nearly neon orange color. If I could make an aesthetic change, I'd prefer a black plastic used here.

The package comes with a compact wall-charger for the 2800mAH 18650. Small, lightweight, seems to work well.

The focus ring is threaded similarly to the endcap, with an O-ring protecting a lot of threading.

The focusing function makes a difference. I'll have measurements next week, but eye-balling it, I'd say it gives about 10:1 control over beam width.


Power

Let's just say that it's not over-rated. We test very briefly on a Thor Labs tester, so consider these numbers very preliminary.

Working on a partially charged cell, the device hit 460mw as soon as turned on. Within a second or so, it was in the 520mw range. After 10 seconds or so it settled into a channel between 560mw and 630mw with observed peaks at 660mw+.

Note: The variability in these numbers is likely due to the fact that I had the pointer hand held to the Thor Labs with no guarantees of good alignment of the pointer aperture and the sensor aperture. We'll have time next week to set up a proper test rig.

Anecdotal Power at a Distance. I have a 200 meter tower approximately 1Km from my house. The pointer hit the reflective metal base of the top lamp on the tower. Even with the scatter and divergence, it bounced back a reflection that gave me an immediate wince.

<<My rigs at the office allow me to do tightly controlled measurements at 30m indoors and high alignment measurements at 700m and 1.4Km. We should be able to get much more quantitative next week.>>

Overall Preliminary Opinion

Couldn't be happier. A well made, nice looking housing, a laser operating a minimum 75% above it's nominal 350mw minimum, peak power almost double that.

For $212, I'm a satisfied customer.

Mike Chambers
President, mc3 research

Chief Strategy Officer, SkyFiber, Inc.

Hehe nice nice stuff man happy to read it's overspec just as mine and mine...well i use it a LOT , i made a temp TEC to keep it nice @ 28.C and it's going strong for hours.

Im looking forward for some pics.

Have a nice weekend along.

@ mikec,

Glad to hear that your laser is overspec and good. Looking forward to the complete review.

Could you tell me when did you order? Because I want to know from which batch is your laser.

Mine seems to be good as well (ordered on March 10 and received on April 10), but since I don't have a LPM I can't tell what is the real output. However, I managed to light a match 2 meters distance when well focused (it took a while though). So if that can imply of the power, how much power do you thing that my laser have?

I believe I ordered about March 21. I'd seen these on sale earlier, but I was still researching when they ran out. I happened to see the special on their page again and 9 were left.

I'm somewhat "in" the laser business. Our products use 850nm lasers and avalanche photodetectors for infrared wireless broadband.

Regardless of the batch that these are from, I wouldn't be surprised at a fairly wide variance in the "overspec." Our products use lasers from a high-profile manufacturer and we order several hundred to 1,000 at a time. We screen each laser at multiple steps of the manufacturing and QC process (including a 24x7 day outdoor burn-in). It's rare to see two lasers a day at the same performance level. That's ok as long as they are above our minimum requirements.

Be aware that there is a downside to running significantly overspec. A laser driver can only handle so much. Heat sinking or TE cooling can reduce the exposure of the driver to overheating, but it can't protect the components from stress.

As to the question on inferring power output from the ability to light a match at two meters ... I haven't the foggiest clue. Perhaps others on the forum may venture a guess. I believe that backing into a calculation would require you to know the actual beam size and actual divergence for your particular device as focus. This should give you the beam diameter in the far field. You would then need to look at the size of the match head as a percentage of the far field beam diameter to determine how much of your device power was striking the combustible surface. I suspect you could probably find a range of ignition temperatures from Wikipedia or elsewhere on the web. You'd then need to determine the mass of the ignition area exposed to beam to get to delta-T/cm2/s. That will lead you on to the number of Joules that will eventually let you get to mw/s.

My laser lab guy could probably find a 1000 mistakes in the above, which is why I say I haven't the foggiest clue. Accurately calculating the number with the info you have (and realistically, the accuracy of the information you might further collect) makes it fairly unlikely that you'll wind up with a number close to right.

If I had to venture a guess, I'd guess you're running over 500mw, possibly a fair amount over 500.

Best,

Mike

I'd love to see a pic of the TEC approach you used.

I've toyed with the idea of building an "uber-host" designed to last a lifetime, allow modules to be swapped easily, passively dissipate 500mw and have a switched TEC on the leading edge of the fin area. The uber part, however, is 8 hours of continuous operation with TE cooling on. Yes, it's ridiculous; but so is having a laser pointer that could blind anybody in Reliant Stadium.

My wife's out of town next week, which means that my Rebel Alliance (an officer of the company that is a recovering geek who has amassed a team of brilliant misfits from across the company) will have free reign with time and support personnel to do a proper just of reviewing my latest "extreme diversion." Who knows, there may even be YouTube.

For any other "extremists" out there ... my last extreme product was a line of uber hot-sauces in 9 intensities under the product line "Dante's Hell of a Hot Sauce." This sauce was also used to make my spiced holiday pickles and garlic, quality tested by a former Army Ranger working with me. He has certified them, delicious, deadly, and as impressive as blow drying your hair with pepper spray. I have a few jars left for any extremists with a culinary death wish. Just will your laser gear to me before eating.

As a bit of trivia along the lines of "relief from eating stuff like Mike's pickles"... Capsicum (the "hot" in a hot pepper) is only soluble in low viscosity oils and in ethanol. (Acutally, there are industrial solvents; but your unlikely to have them on hand -- and they are toxic to humans.) Water is actually an aerosolizing disburser; i.e., put water on this stuff and you just created a nice mouthful of hot gas.

If you have eaten something to hot to handle, here's a tip you won't find elsewhere. Many folks know that proteins in milk bind to capsicum molecules, which helps. However only so much can bind at a time. Alternating a milk gargle and sipping a half-shot of whiskey works better than anything else I've found. The ethanol dissolves the next layer of capsicum. Spit the milk, swallow the whiskey. It got me through an 8M Scoville encounter; it should work for you too.

mike

Eating spicy makes me drunk!

mikec said:

I believe I ordered about March 21. I'd seen these on sale earlier, but I was still researching when they ran out. I happened to see the special on their page again and 9 were left.

I'm somewhat "in" the laser business. Our products use 850nm lasers and avalanche photodetectors for infrared wireless broadband.

Regardless of the batch that these are from, I wouldn't be surprised at a fairly wide variance in the "overspec." Our products use lasers from a high-profile manufacturer and we order several hundred to 1,000 at a time. We screen each laser at multiple steps of the manufacturing and QC process (including a 24x7 day outdoor burn-in). It's rare to see two lasers a day at the same performance level. That's ok as long as they are above our minimum requirements.

Be aware that there is a downside to running significantly overspec. A laser driver can only handle so much. Heat sinking or TE cooling can reduce the exposure of the driver to overheating, but it can't protect the components from stress.

As to the question on inferring power output from the ability to light a match at two meters ... I haven't the foggiest clue. Perhaps others on the forum may venture a guess. I believe that backing into a calculation would require you to know the actual beam size and actual divergence for your particular device as focus. This should give you the beam diameter in the far field. You would then need to look at the size of the match head as a percentage of the far field beam diameter to determine how much of your device power was striking the combustible surface. I suspect you could probably find a range of ignition temperatures from Wikipedia or elsewhere on the web. You'd then need to determine the mass of the ignition area exposed to beam to get to delta-T/cm2/s. That will lead you on to the number of Joules that will eventually let you get to mw/s.

My laser lab guy could probably find a 1000 mistakes in the above, which is why I say I haven't the foggiest clue. Accurately calculating the number with the info you have (and realistically, the accuracy of the information you might further collect) makes it fairly unlikely that you'll wind up with a number close to right.

If I had to venture a guess, I'd guess you're running over 500mw, possibly a fair amount over 500.

Best,

Mike

Click to expand...

Thank you for your detailed answer.

Yes, it's much more simple to get a LPM and measure the output directly than doing complicated calculations with large error margins.

Unfortunately, the LPM that I want (the Radiant Alpha) is not available ATM.

There is a guy here who builds them and he is not doing it on a regular basis so you have to wait until he shows up with an update here that he made some and then hope that you will have a chance to buy one before they are out of stock again.