Lecture Reviews about Diode Lasers in powder bed fusion

Write a lecture review about the diode laser, answering the following with images and references
What is a diode laser?
How does it work?
What is the advantage of using a diode laser in the PBF process?
What are the limitations of using DL in PBF
How can we collimate and fiber couple the diode laser?

I can supply the references and more details.
I am looking for 1500 _2000 words.

Make sure no use for Al.