Laser beam combination. New approach

Thanks to Henrik Kulcsár and Thomas Sebastian we have started development of a new laser beam combiner module.
This time we will combine 4 beams in one.

As you know we made some research with laser beam prisms and it worked

Previously we made 30 watt (triple beam) laser module.

Triple beam diode laser – 30 watt (30000 mw) of optical power in one spot using NICHIA laser diodes

Here is a drawing of possible construction

Here is a projected assembling process

and a theoretical overview about Laser beam Combining mechanism

20 watt laser (double beam laser) has some difficulties with focusing

The Endurance 20 Watt (20000 mw) 445 nm double-beam diode laser add-on (attachment) for a 3D printer, a CNC and an engraving machine

however, laser engraving is very efficient

https://www.youtube.com/watch?v=nYwxoFo0oII

All ideas and comments are welcome!)