Identify 5.6mm with 4 leads?

[450nm]

Just got a few 5.6mm red diodes. Bit oddball. anyone know anything? Fairly low power They take 100mA and I'd guess are putting out around 20-40mW. What might identify them is that instead of 3 leads they have 4 which I assume are totally isolated LD and PD. They are open emitter and linear in operation. No numbers on them. I can get them fairly cheap if they are of any use.

TIA

[pseudonomen137]

Just got a few 5.6mm red diodes. Bit oddball. anyone know anything? Fairly low power They take 100mA and I'd guess are putting out around 20-40mW. What might identify them is that instead of 3 leads they have 4 which I assume are totally isolated LD and PD. They are open emitter and linear in operation. No numbers on them. I can get them fairly cheap if they are of any use.

TIA

I've seen some 150mW 978nm diodes with 4 leads. Instead of having a combined lead between the photodiode and laser diode, it had two separate sets of pins for each. At 100mA though, we're obviously talking about different spec'd diodes here =/