Mitsubishi ML520G71...Red Holy Grail or Flashlight Fail ??

[andyf97]

well done, you will find when you use a lens with a smaller FL like 2mm - 3mm, you wil lget even better results.

It makes a pretty good dot, just haven't gotten to scanners yet as it is all just test platform right now.

[polishedball]

well done, you will find when you use a lens with a smaller FL like 2mm - 3mm, you wil lget even better results.

Good to know, I just got impatient I have some other lens on the way, can;t wait.

[Solarfire]

Also Andy you were correct it was a Lens issue, after reading about some results with the 405-g-2, I tossed a o-like blue on it and got good results.

I have some <3mm FL's on the way so hopefully they will help even more.

Attachment 28575

If I understand you correctly you swapped the 405-G-2 lens for an O-Like and you are happy with the results? You do know that the O-Like is a longer fl than the 405-G-2 and that the reason for getting a subjectively better beam is the clipping of the fast axis and huge loss?

Andy... still waiting on some data on the mystery lens?

[polishedball]

If I understand you correctly you swapped the 405-G-2 lens for an O-Like and you are happy with the results? You do know that the O-Like is a longer fl than the 405-G-2 and that the reason for getting a subjectively better beam is the clipping of the fast axis and huge loss?

Andy... still waiting on some data on the mystery lens?

I did not have a 405-g-2 available, others are on order. I just had a O-Like Blue half thread not full around got impatient waiting and decided to test. The 405-g-2 i would expect better results from if the FL is smaller, but I was just playing around until real lens arrive.

Also not sure what you mean by huge loss as this will still put out 600mw when driven hard, I just kept it down since there was no cooling and wanted the stability. It ran at 400mw steady for over an hour and half.

[steve-o]

400mW with an o-like lens? Wow. Is this with a HL6388 or MG520G71?

[polishedball]

400mW with an o-like lens? Wow. Is this with a HL6388 or MG520G71?

MG520G71

15char

[Solarfire]

Also not sure what you mean by huge loss as this will still put out 600mw when driven hard, I just kept it down since there was no cooling and wanted the stability. It ran at 400mw steady for over an hour and half.

See post 38.. here a small cutout: The raw diode power without optics = 312mW @ 400mA
I then tried an O-Like which gave some halfway usable results. Output after the O-Like coli was 190mW and after prisms (prisms setup @ Zoofs Brewster angle) 168mW. Divergence after prism correction was @ 1.66mrad. Beam size @ the prism aperture 4.5mm x 1.75mm, farfield 4.5mm x 20mm.

Sure you can get 400mW driving the diode hard but the loss is still > 38% just on the O-Like lens. That means with a lens like the Optima (4mm FL, >97% transmittion) you will get approximatly 540mW at the same power. Get the picture?

[logsquared]

I got 290mW at 500mA with the MG520G71 using an olike red coat lens. The lens looks identical to the aixiz glass. The math says it should be around 200mW. I guess there is more power in the center of the beam? I don't really understand it. The divergence was around 4mRad.

@polishedball: what current is that at? I haven't taken mine over .5A. Very tempted though.

[logsquared]

I happened to have the diode on the bench. So, i retested with the olike red coat. I used a precision ammeter to be sure the current was correct this time. At 400mA got 223mW at 500mA got 302mW.

[Solarfire]

I happened to have the diode on the bench. So, i retested with the olike red coat. I used a precision ammeter to be sure the current was correct this time. At 400mA got 223mW at 500mA got 302mW.

Sounds right, my test was with the O-Like blue coat. Do you know the FL of the red coat?