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Urgent help with 1W Sanwu 405 nm Silver

KMitch

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Hello all, I know it's been awhile! I recently added a 1W 405 nm Sanwu Silver to my collection that arrived on August 2. It took a couple weeks for me to schedule my laser to be metered, and I planned to write up a review once I had that data.

One of the research scientists at the Texas Petawatt Laser Facility was nice enough to measure the power of my new laser, as well as a 200 mW 532 nm LasesBTB that I wanted to measure again since it fell 5 feet onto concrete.

The output of the 532 nm was 300-330 mW, the same as last year which is reassuring. However, the 1W 405 nm averaged 500 mW and peaked at 550 mW, far below what I paid for. We used a lens to broaden the beam, and found that it had no effect on the output. We even risked damaging the meter by taking one measurement without the lens, getting the same readings.

I contacted Sanwu and attached a picture of the set-up and reading. They responded, "There is no way it metered around 500mw only with G2 lens, how long the test lasted? 405nm diodes usually requires 40-60 seconds to warm up and reach its full power. We would suggest you to try another 18650 batteries as well".

The laser had been turned on and of quite a few times before taking measurements, and I don't think warm up was an issue. The batteries were protected LG MG1 18650's, fully charged. This is an excellent battery, and buying from Liion I know they're real.

Here's the problem. The research scientist is moving for a new job as director of a Free Electron Laser facility on Monday, and I don't have any more contacts at the Petawatt facility. Are there any members in Texas who would be willing to meter this for me with their meter, and their batteries? If not in Texas, I could ship the laser to a trusted member within the US, preferably closer to Texas. The urgency is related to the length of time Sanwu will wait before they refuse to replace a defective product. Pictures below.


 
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paul1598419

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Obviously the guy at Sanwu has only experience with TEC based laser power meters and that is what his questions are about. In order to get an accurate reading on a TEC base meter you need to allow the light to fall on the sensor for up to a full minute. Tell them that a PhD at a laser facility did the testing with a calibrated Coherent Laser Power Meter. Tell them it is absolutely accurate and you are angry that they conned you.

Show them these photos. And explain that your meter is much more accurate than theirs.
 
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KMitch

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Obviously the guy at Sanwu has only experience with TEC based laser power meters and that is what his questions are about. In order to get an accurate reading on a TEC base meter you need to allow the light to fall on the sensor for up to a full minute. Tell them that a PhD at a laser facility did the testing with a calibrated Coherent Laser Power Meter. Tell them it is absolutely accurate and you are angry that they conned you.

Show them these photos. And explain that your meter is much more accurate than theirs.
It's very frustrating since I showed the the photos, the meter, and explained how it was tested, yet they don't believe the test. We've talked before and I trust you as a member. If I ship my laser to you and pay for return shipping, would you be willing to test it out? If you don't have time, no problem at all. I'll message hakzaw1 in the mean time, since I believe he's in Texas.
 

paul1598419

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Absolutely, Mitch. Send me a PM and I can set that up for you. I'm sure I'll come up with the same results your friend did. The only question is will Sanwu take two separate measurements as proof?
 

KMitch

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Absolutely, Mitch. Send me a PM and I can set that up for you. I'm sure I'll come up with the same results your friend did. The only question is will Sanwu take two separate measurements as proof?
Thank you Paul. Sanwu wanted me to test other batteries as well, and I think an independent test with a different meter and different batteries showing the same result would be very convincing. Since you're a well-known member, I think your test would also carry more weight than mine. I would reference your test and this thread when sending Francis and Sanwu a reply.

I'm pretty confident in the test done by the Petawatt facility because the power on my 200 mW rated 532 nm read 300 mW, which is typical for LaserBTB. If it were lower than 200 mW, I might question the meter. The facility doesn't deal with CW very often and the meter had been stored for awhile in a box, so it's possible that the calibration was off. I'll send you a PM in a minute.
 

paul1598419

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I can send you a data logging printout of the test also. I have many, many batteries and could test it with several, if that's what they want. I can also post a printout of the test here, also.

BTW, you are only 4 posts away from being a rated member here.
 
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lasersbee

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Hello all, I know it's been awhile! I recently added a 1W 405 nm Sanwu Silver to my collection that arrived on August 2. It took a couple weeks for me to schedule my laser to be metered, and I planned to write up a review once I had that data.

One of the research scientists at the Texas Petawatt Laser Facility was nice enough to measure the power of my new laser, as well as a 200 mW 532 nm LasesBTB that I wanted to measure again since it fell 5 feet onto concrete.

The output of the 532 nm was 300-330 mW, the same as last year which is reassuring. However, the 1W 405 nm averaged 500 mW and peaked at 550 mW, far below what I paid for. We used a lens to broaden the beam, and found that it had no effect on the output. We even risked damaging the meter by taking one measurement without the lens, getting the same readings.

I contacted Sanwu and attached a picture of the set-up and reading. They responded, "There is no way it metered around 500mw only with G2 lens, how long the test lasted? 405nm diodes usually requires 40-60 seconds to warm up and reach its full power. We would suggest you to try another 18650 batteries as well".

The laser had been turned on and of quite a few times before taking measurements, and I don't think warm up was an issue. The batteries were protected LG MG1 18650's, fully charged. This is an excellent battery, and buying from Liion I know they're real.

Here's the problem. The research scientist is moving for a new job as director of a Free Electron Laser facility on Monday, and I don't have any more contacts at the Petawatt facility. Are there any members in Texas who would be willing to meter this for me with their meter, and their batteries? If not in Texas, I could ship the laser to a trusted member within the US, preferably closer to Texas. The urgency is related to the length of time Sanwu will wait before they refuse to replace a defective product. Pictures below.


I would have liked to see the entire Coherent
210 Power meter... not just the Needle Scale.

When was the last time that the 210 LPM was
calibrated ?? It is an old Coherent LPM and not
a top of the line model...

I would suggest that you take a current reading
at the batteries to see what current is being
drawn by the Driver and supplied by the batteries.

You may have a defective Laser. It could have
happened during transport.

Either way Paul will be able to test it.


Jerry
 
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KMitch

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Yes, I trust that Paul will do an excellent job. Like you said, calibration could be off on the LPM since it's not used very often at the lab. I'll hold back criticism of the product until the results come back. The 3W spiker was excellent, and I'm very impressed by the build quality of Sanwu overall.

Two other issues I noticed with the 405 nm Silver was the splash around the dot, and the fact that the beam narrows to a point about 15 feet in front of the diode even though it should be focused to infinity out of the box. I'll be interested in what Paul will have to say about it when he receives the laser. It may simply be that I need to use a spanner wrench to slightly adjust the collimating lens. The splash didn't go away with an air gun, but after the test I could give it a wipe with cleanroom grade isopropyl alcohol and a lens wipe.
 
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Hello all, I know it's been awhile! I recently added a 1W 405 nm Sanwu Silver to my collection that arrived on August 2. It took a couple weeks for me to schedule my laser to be metered, and I planned to write up a review once I had that data.

One of the research scientists at the Texas Petawatt Laser Facility was nice enough to measure the power of my new laser, as well as a 200 mW 532 nm LasesBTB that I wanted to measure again since it fell 5 feet onto concrete.

The output of the 532 nm was 300-330 mW, the same as last year which is reassuring. However, the 1W 405 nm averaged 500 mW and peaked at 550 mW, far below what I paid for. We used a lens to broaden the beam, and found that it had no effect on the output. We even risked damaging the meter by taking one measurement without the lens, getting the same readings.

I contacted Sanwu and attached a picture of the set-up and reading. They responded, "There is no way it metered around 500mw only with G2 lens, how long the test lasted? 405nm diodes usually requires 40-60 seconds to warm up and reach its full power. We would suggest you to try another 18650 batteries as well".

The laser had been turned on and of quite a few times before taking measurements, and I don't think warm up was an issue. The batteries were protected LG MG1 18650's, fully charged. This is an excellent battery, and buying from Liion I know they're real.

Here's the problem. The research scientist is moving for a new job as director of a Free Electron Laser facility on Monday, and I don't have any more contacts at the Petawatt facility. Are there any members in Texas who would be willing to meter this for me with their meter, and their batteries? If not in Texas, I could ship the laser to a trusted member within the US, preferably closer to Texas. The urgency is related to the length of time Sanwu will wait before they refuse to replace a defective product. Pictures below.


Gees if there is any question at all that one of their products was not working as advertised they should have asked you to send it back so they could verify the problem and if necessary repair or replace it !

We don't believe you is unacceptable ! IMHO
 
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lasersbee

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Let us know the results of Paul's tests
if he's doing them.
BTW... even if the 210 LPM calibration is
off... I don't think it would be that far
off. (50%:thinking:)

Jerry
 
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KMitch

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Let us know the results of Paul's tests
if he's doing them.
BTW... even if the 210 LPM calibration is
off... I don't think it would be that far
off. (50%:thinking:)

Jerry
Will do! I'm sending Paul the laser on Monday through Priority mail.
 

Podo

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This is the first reply we sent him after he told us the lpm result:

"There is no way it metered around 500mw only with G2 lens, how long the test lasted? 405nm diodes usually requires 40-60 seconds to warm up to reach its full power.

We advise you to try another 18650 batteries as well, many times batteries is the reason behind the decrease power of the laser.

Yet if you think there is no problem on your end, you can always send the laser back and we will test it and make sure it's over 900mw when it's back to your hand."

We have explained the possible reason of the problem, we asked for a 40-60 seconds test, our power rating is not determined by peak output and we also offered a full restoration.

We will issue a full refund if he doesn't feel like it and return the laser.
 
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This is the first reply we sent him after he told us the lpm result:

"There is no way it metered around 500mw only with G2 lens, how long the test lasted? 405nm diodes usually requires 40-60 seconds to warm up to reach its full power.

We advise you to try another 18650 batteries as well, many times batteries is the reason behind the decrease power of the laser.

Yet if you think there is no problem on your end, you can always send the laser back and we will test it and make sure it's over 900mw when it's back to your hand."

We have explained the possible reason of the problem, we asked for a 40-60 seconds test, our power rating is not determined by peak output and we also offered a full restoration.

We will issue a full refund if he doesn't feel like it and return the laser.
That sounds reasonable, No need for a second test now, Just send it back to the manufacture....
 

GSS

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Why would a direct 405 diode need a warm up? Other 445's etc. seem to only need 1 or 2 seconds.
 
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Podo

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Why would a direct 405 diode need a warm up? Other 445's etc. seem to only need 1 or 2 seconds.
Not exactly the diode but the driver we use for 405nm diodes is a soft-start driver, it takes time for the diode to reach its full power.
 
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