Square shaped aberration in new blue laser diode. Should I ask for a replacement?

This is a picture I took of the light from the laser shining on a door, with a pencil blocking the actual beam so that the light from the aberration would show up better. (The pencil started smoking while I was trying to take this picture.)

Have tried cleaning the optics with a lint-free microfiber cloth meant for camera lenses, and with isopropal alcohol and q-tips. No effect. Should I try to get a replacement, or is this normal? Is there an easy way to fix it myself?

This is a PLT5 450B, 450nm laser diode with G-2 Glass Lenses. I got it as part of an RGV bundle from DTR's Laser Shop.

This is completely normal, caused by reflection within the diode.
It will always happen with multimode diodes and G2 lenses.
If you use a 3-element or G7 lens, you will eliminate this splash.

Sta said:

This is completely normal, caused by reflection within the diode.
It will always happen with multimode diodes and G2 lenses.
If you use a 3-element or G7 lens, you will eliminate this splash.

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Sta, you're signature is becoming too darn long op:

-Alex

Hap said:

Sta, you're signature is becoming too darn long op:

-Alex

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Haha yes, I've been thinking of cutting it down. Tried to put it into a just wavelengths form (like rhd) but that just ended up looking bad. Any ideas?

Sta said:

Haha yes, I've been thinking of cutting it down. Tried to put it into a just wavelengths form (like rhd) but that just ended up looking bad. Any ideas?

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Ask CurtisOliver if he'll send you the fancy spreadsheet he used to make his.

diachi said:

Ask CurtisOliver if he'll send you the fancy spreadsheet he used to make his.

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I actually wrote up a java program to do that more quickly (and used it in the past!) but haven't been able to locate it lately.

PatrickJS said:

This is a picture I took of the light from the laser shining on a door, with a pencil blocking the actual beam so that the light from the aberration would show up better. (The pencil started smoking while I was trying to take this picture.)

Have tried cleaning the optics with a lint-free microfiber cloth meant for camera lenses, and with isopropal alcohol and q-tips. No effect. Should I try to get a replacement, or is this normal? Is there an easy way to fix it myself?

This is a PLT5 450B, 450nm laser diode with G-2 Glass Lenses. I got it as part of an RGV bundle from DTR's Laser Shop.

Click to expand...

Betcha that's schmutz on the diode window. If you have a high power magnifying glass or a jewlers loupe take a look at the diode window. Schmutz on optics produces that same spotty pattern that's why I think it's schmutz. I also have a high power 405nm laser with the same problem. It has something on the window.

My 405 challenger has the square too with a -g7lens perfectly normal on these diodeseven my green pen build has it with a 3e lens however it is fainter.