Not symmetrical box reflection on laser diode

Hello,

As you know, when using G2 lens a reflection like a box are projected.
It's not dependant from model of diode.
Symmetrical or not symmetrical vary from diode to diode.

You can get this two case (Symmetrical or not symmetrical projected reflection) on singlemode or multimode and for any wavelenght.

But why we get this "problem" on a industrial machined process ? "diode dies can be badly aligned ?"

My picture show a multimode green perfectly manufactured (NDG7475) and a not symmetrical blue (NDB7875). I have a symetrical NDB7875 blue also !

- And you, do you get symmetrical/centered or "misaligned" reflection on you diode (and what model) ?
- Anyone for a more technical explanation on diode manufacturing tolerance and why we can get this ?

Thanks
Pascal

EDIT : it does not vary from one diode to another from same model.

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