I think that the lasers are proprietary, since they seem to only be found in Playstation 2 consoles.
In the first place, even some PS2s cannot use the lasers from other units (E.g. there is no way for my SCPH-10000 with a KHS-400A to use the HD7 laser from my SCPH-39006 console), so there is no such thing as a "all-PS2-model" compatible laser to begin with.
(Inter-console-compatible lasers will probably be even less likely to exist!)
Otherwise, I don't see why we (especially us users of older consoles that sport the KHS-400A laser) have a shortage of Lasers in some regions.
What about those 3rd party compatibles (E.g. KHS-400H, KHS-400Q and KHS-400W lasers)? They seem to come cheap and might work better than some of the Sony and Sanyo lasers.
SCPH-10000 S. MINOKAMO v1.01 (Defunct)
SCPH-10000 S. KISARAZU v1.00 (faulty)
SCPH-15000 S. KOHDA (With warranty seal!) :D
DESR-5100 S. EMCS