Suggestions welcome on how to verify the power of DPSS and diode lasers

[taggalucci]

I'm still waiting for "taggalucci" to contact us with the
info we requested yesterday...

Done. Thank you Jerry

[lasersbee]

Done. Thank you Jerry

I received your PM this morning and sent you a reply...

After reviewing the information and pics I received... I can state that the
LaserBee I we sent to "taggalucci" is still calibrated and the Sensor surface is still
in pristine condition... I would trust the readings that his LaserBee I displays....

Sometimes an enthusiastic buyer will "play" with the LaserBee and de-calibrate
the LPM or burn/scorch the surface of the Thermopile Sensor (BEFORE reading
the User Instructions) which may throw the calibration off...
It is definitely NOT the case here...

Jerry

[taggalucci]

Thanks for that Jerry

After reviewing the information and pics I received... I can state that the
LaserBee I we sent to "taggalucci" is still calibrated and the Sensor surface is still
in pristine condition...

That's the way I roll

I would trust the readings that his LaserBee I displays....

My immediate suspicions are the CNI lasers. After verifying driver and signal voltages, I will most likely need to get an independent measurement before returning to China under warranty.

[lasersbee]

Thanks for that Jerry

That's the way I roll

My immediate suspicions are the CNI lasers. After verifying driver and signal voltages, I will most likely need to get an independent measurement before returning to China under warranty.

Yeah... I would get your lasers checked on another Meter before making any
decisions... Post back here and let us know what the results of the side by side
independent measurements are...

Jerry

[taggalucci]

Just an update...

This evening I am taking the two lasers and my LaserBee I to Dave's to have an independent measurement. As a result of having to remove the two lasers from the projector for this purpose, I was able to take further measurements, using the LaserBee I, of the lasers using a 5v signal applied directly to the laser drivers.

From doing this, I now suspect that my MediaLas SafeGuard Lite is attenuating the signal voltage between the ILDA input and the laser drivers. I will need to look into this seperately to confirm whether my suspicions are correct.

I measured:

• 1,005mW - 1,009mW from the 635nm, very stable after waiting 5 mins to warm

• 330mW - 370mW from the 532nm, which fluctuated up and down within the range after waiting 15 mins to warm

So according to the LaserBee I, the red is about 100mW over spec and the green, about 100mW under.

I'll have an update after seeing Dave this evening.

[dave]

Just an update...

This evening I am taking the two lasers and my LaserBee I to Dave's to have an independent measurement. As a result of having to remove the two lasers from the projector for this purpose, I was able to take further measurements, using the LaserBee I, of the lasers using a 5v signal applied directly to the laser drivers.

From doing this, I now suspect that my MediaLas SafeGuard Lite is attenuating the signal voltage between the ILDA input and the laser drivers. I will need to look into this seperately to confirm whether my suspicions are correct.

I measured:

• 1,005mW - 1,009mW from the 635nm, very stable after waiting 5 mins to warm

• 330mW - 370mW from the 532nm, which fluctuated up and down within the range after waiting 15 mins to warm

So according to the LaserBee I, the red is about 100mW over spec and the green, about 100mW under.

I'll have an update after seeing Dave this evening.

Red should be more or less stable after a very quick warmup. But remember the ambient temperature in Melbourne is pretty cold ATM, so it might take the green a lot longer to wake up, as the TECS are only driven to cool and not to heat and cool

[taggalucci]

Thanks very much to Dave for his help this evening and taking the time to help me out

Dave's meter readings were within a few mWs of the LaserBee's which leaves me feeling comfortable that the LaserBee is perfectly fine for providing indicative absolute values which more than satisfies my requirement from an enthusiast meter like this.

I will take Dave's advice to run the green for a couple of hours to allow it to warm before making any bold statements about it being underpowered.

I think it's an interesting point though that ambient temperature should potentially have such a marked impact on the performance of these lasers (in this case 70 - 100mW). It occurs to me that the procedure for calibrating colour palettes (such as in LD2000) should account for this.

[buffo]

If you think your green is sensitive to temperature changes, you should see what happens to my Lasever dpss blue when the temperature drops!

I actually had to install a kill switch on my case fans, because twice I've been using my projector outside (backyard) when the temperature was cool (mid 40's Fahrenheit), and both times the output of my blue laser dropped to around 10% of it's rated output. Talk about panic mode! But as soon as it warmed up, the power came back to normal.

Now I always keep temperature in mind when running the projector.

Adam

[lasersbee]

Thanks very much to Dave for his help this evening and taking the time to help me out

Dave's meter readings were within a few mWs of the LaserBee's which leaves me feeling comfortable that the LaserBee is perfectly fine for providing indicative absolute values which more than satisfies my requirement from an enthusiast meter like this.

Thanks for doing the tests on another LPM to verify your LaserBee I... and we are
happy that you are comfortable and satisfied with your LaserBee I's results..

Jerry

[taggalucci]

Taggalucci has already stated that power seems to increase beyond 5v modulation, maybe a. the assumed 5v is not 5v, b, there is some connection problem between the mod signal and the lasers, c. the lasers *are* down on power?

Yup correct Doc, as it turns out, most likely on two counts...

Initially your point B - due to the scanfail attenuation and, potentially C - due to the lack of willingness of the CNI greenie to perform. Stage-fright perhaps? Must be something to do with the cold weather