Understanding Usage of Multimode OM1 OM2 Fiber Cables

If we have a multimode OM2 50/125 µm fiber backbone, is it possible to use multimode OM1 62.5/125 µm fiber patch cables on each end? Or vise Versa?

From 50 µm fiber backbone to 62.5 µm fiber jumpers, it’s OK on the receiver end, but on the transmitter end, the larger core of 62.5 µm into smaller 50 µm fiber will have losses of 2~4 dB.

From 62.5 fiber backbone to 50 µm fiber jumpers, the excess loss is at the receiver end, not at the transmitter end.

Can I splice 62.5/125 µm fiber to 50/125 µm fiber? If so, what type of nominal loss would I be looking at?

If you splice them, you’ll get directional losses.

Transmitting from 50 µm to 62.5 µm fiber, you’ll get virtually no losses but from 62.5 µm to 50 µm, you’ll get a minimum of 1.6~1.9 dB loss due to the size and NA (numerical aperture) mismatch.