LR optics don’t require attenuators.

OP didn’t mess up the text. They clearly wanted bidi optics as they only ran one strand.

Can you identify what those 1.4km transceivers are? https://www.aliexpress.com/wholesale?SearchText=1.4km+10g

Are they even remotely standard compatible?

1.4 km is a curious distance. Perhaps they are optics that didn’t make the 2 km cut and are sold at a discount?

I wouldn’t worry too much about the standards. There are lots of optics that don’t stick to the standards, but go above and beyond.

I’m more interested in the use case at hand and if the specs will support the use case.

I saw a lot of singlemode wired datacentres in China, worked on them, but never bothered to look what they use for hardware. I wonder if this is the proprietary semi-standard that big Chinese telcos push for top of the rack hardware.

I once heard that Huawei was trying to do singlemode with VCSEL laser, but the descriptions clearly identify those as using 1310nm DFB http://www.6comgiga.com/downloadRepository/826d97f5-c91a-454... . It is not a 2km multimode

I mean, the item on the aliexpress. I always thought that 10G LR has quite a big minimum length.

Edit: in practice, only 2m minimum length with normal LR transceivers actually.