Looking at it more closely, I agree , it does appear to be a laser diode emitter or multiple emitter rather than an LED.That's my thinking, I've seen similar packages before for other LDs. Never for an LD.
Not to mention the position of the chip, an LED that large would be emitting for a large surface area, not the edge of the chip like an LD. Meaning that the chip would be rotated 90° so that the larger top surface of the chip is facing out, in the case of an LED.
Interested in seeing more, looks like a massively beefy LD. Wonder what the beam specs are like...
Perhaps grenadier will chime in with some answers as to what it is and original use, rather then leave everyone hanging/wondering.