S-KY 150mW 473nm Blue DPSS laser

A lot of people have been waiting for this, here is a review of a 150mW rated S-KY blue dpss laser.

Review in PDF form here

This laser was good in some areas, weaker in others but in the right conditions performed very well. The thing is, those 'right conditions' may not exist inside your common laser projector! Read on for more detail and to see some totally different test methodologies. This is more than your typical 'I got it and wowsa it was bright and keeps working' review.

Comments and criticism welcome!

Bridge, if you see this, I'd love to run the laser that you loaned to Marconi for testing through a few of these tests to see how it compares! Post here if interested!

A comprehensive review, mate. :)

It would be good to see a standard series of tests so that comparing "like for like" would be a lot easier (and your tests look like a good place to start).

hehe, we are interesting, maybe I need asking Marconi, it is very difficult to contact with Marconi as you know.
would you like asking the guy from S-ky send lasers to a crossbencher for test, just like "Buffo", the most professional and kindly man.
"Buffo" any interesting? thanks.
Best regards!
Bridge

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Bridge, if you see this, I'd love to run the laser that you loaned to Marconi for testing through a few of these tests to see how it compares! Post here if interested!

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before compare, please run about 5000hours continue first as the one we send to Marconi, thanks!
Best regards!
Bridge

I'd be willing to do a review - sure. However, I think that Andrew's review is far superior to anthing I could put together. He's got the fast photodiode needed to accurately test the blanking response. (I don't):(

In fact, now that the topic is on the table, I'd like to re-visit the whole idea of a "PhotonLexicon approved list of laser specs" like Pitts was talking about a while back. (Scroll down to about post # 60 or so) That thread sort of died out, but I thought the idea was a good one. Dr Lava has the equipment needed to test this...

By the way, Andrew... One small correction: the first two power graphs are labeled as milliwatts, but if you look at the scale, clearly you meant to label it as watts. Might want to change that.

Adam

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Originally Posted by bridge

hehe, we are interesting, maybe I need asking Marconi, it is very difficult to contact with Marconi as you know.
would you like asking the guy from S-ky send lasers to a crossbencher for test, just like "Buffo", the most professional and kindly man.
"Buffo" any interesting? thanks.

before compare, please run about 5000hours continue first as the one we send to Marconi, thanks!
Best regards!
Bridge

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Hi, yes I know it is very difficult to get in contact with him, but it would be worth it. I am primarily interested to see how the modulation linearity and blanking response is. For the power output, I won't compare due to the different ages of the lasers as you note.


Buffo, thanks, mW->W correction done :)

Good to see such a quality review; the detailed modulation response is very useful. Thanks DrLava!

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Originally Posted by greenalien

the detailed modulation response is very useful.

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I agree. In fact, I'm thinking that Dr Lava needs to bring his fast photodiode and oscilloscope to the next SELEM so we can test a bunch of lasers! :D

Seriously though, that's one of the most thorough reviews I've read in a long time. Wish I had the equipment to do that here. (Wonder how much that detector cost him.?. Might be a worthwhile investment, especially since I've already got a 'scope...)

Adam

Thanks for the kind words, guys.
The high speed detector used in this review was not a photodiode, those are even faster than is necessary. It was a common miniature polysilicon photocell, like what can be found in calculators. I built it into a detector by placing it into a light-tight black ABS box and cutting a small hole in the opposite side of the box and mounting a diffuser there. A 100 ohm resistor across its leads was used as a current metering shunt. Its power measurements were calibrated per wavelength against the thermal meter, and response linearity error was within 5%.

So, anyone could easily build one themselves for under $10. :D

Damn.... So simple!:rolleyes:

Hmmm. I have a calibrated lasercheck... And I'm sure I could get a cheap silicon solar cell... I smell another project in the works!:D

Thanks for the info Doc! I might get in touch with you later when I attempt this. ;)

Adam

S-KY and laserbtb is the same company.

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Originally Posted by Dr Laser

S-KY and laserbtb is the same company.

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Yes, that's in the first sentence.

not many of us own a PXI bus card and labview, but job well done. I think we can see a need for light feedback!

Dr lava is 45-0 miles from me, so I will do my light feedback board this weekend and hook my yag up to it, then he could plop it on his test bench.



Steve

I don't need Lab view to do the tests... I can use my Oscilloscope for that. True, I can't post the output, but I can at least verify the performance of my own lasers.

I agree that if you're going to do a review, it's better to have the software, as it's nice to have the traces for everyone to see.

Adam

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Originally Posted by buffo

I don't need Lab view to do the tests... I can use my Oscilloscope for that. True, I can't post the output, but I can at least verify the performance of my own lasers.

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If you have a digital camera and a tripod you can take trace images. I have a recipe I use when I'm trying to capture scope display. I turn the room lights down (but not all the way), put the camera about 4ft from the scope display, line it up, zoom about halfway in, and set the camera to "close-up mode" (it's not really a macro setting) and the lowest ISO setting.

Then set up the display on the scope the way I want it and use the self timer on the camera to eliminate that pesky hand wobble. Works a treat!

Good point, Heroic! Since I've got an older scope anyway, I can probably turn up the brightness and get a decent image. Might have to give that a try... Thanks!

Adam

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Originally Posted by buffo

I don't need Lab view to do the tests... I can use my Oscilloscope for that. True, I can't post the output, but I can at least verify the performance of my own lasers.

I agree that if you're going to do a review, it's better to have the software, as it's nice to have the traces for everyone to see.

Adam

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It is said that the camera never lies. ;) While it takes a bit to set up a good shot, a photo of an analog scope is often a more convincing record of events. And if you publish it, no-one can claim it as theirs and post it on some web site without it being obvious to anyone who saw yours.

Edit: Go with Heroic's methods. Works for me too, very similar setup. Just go easy with brightness, you'd be surprised... A clean thin line shows better than a bright fat one, it's way easy to saturate the cam.

While taking photos of scopes with polaroids has been the 'traditional' way of data capture until the 90s, do you really find my DAQ captured data any less convincing? It sure is a lot less time consuming. Plus with many old scopes they don't show the DC offset (position) and/or gain on screen so all you have of record is the squiggly line and no data values, they must be manually written down.

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Originally Posted by drlava

do you really find my DAQ captured data any less convincing?

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Quite the opposite. I think your results are *more* convincing. The problem is that not everyone has the software to do it, thus the "imperfect" solutions of using a camera.

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Plus with many old scopes they don't show the DC offset (position) and/or gain on screen so all you have of record is the squiggly line and no data values, they must be manually written down.

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True. This is where trust in the reviewer comes in. And since I'm not likely to purchase Lab View anytime soon, trust is all I have to go on. ;)

Adam