We ended up purchasing a bunch of these Intel SPTSLP2SLCDF 100G-DR1 optics a few weeks ago for a very specific application. The optics are QSFP28 modules with 500m of reach, utilizing single-mode fiber. Since we had an extra, we did the STH thing and took it apart. This is a neat optical module because it is doing something internally that is a bit different.
Intel SPTSLP2SLCDF 100G-DR1 500m 1311nm QSFP28 Module Quick Look
Intel used to have a business selling optical modules where Facebook/ Meta was its major customer. Ultimately, Jabil Bought the Intel Pluggable Silicon Photonics Business. Still, a huge number of these modules were produced.
QSFP28 modules look fairly similar.
Starting with what makes this interesting is that this side is the QSFP28 connector, which uses NRZ.
On the optical side, we have a single-mode LC connector. Since this is a DR1 optic, it uses PAM4.
Here is a quick look inside. At the bottom, you can see the Inphi IN010C25. Inphi was purchased by Marvell, so this is the Alcor 100G PAM4 DSP. More specifically, this is the 4x 25G NRZ to 1x PAM4 100G variant of the part.
Opening this up, you can see the send and receive side.
Here is a closer shot of the optical engines.
Here is the back side of the PCB.
Inside these modules, we find something a lot more interesting than just looking at the metal case.
Final Words
We needed 32 of these, so we ended up buying 40, and one was sacrificed to bring this piece to you. We previously showed QSFP56-DD 400G DR4 Intel Silicon Photonics optics. That is an optical module that runs four PAM4 100G channels instead of just the one we are looking at here.
These are fairly specific tools and generally, we would not suggest getting DR1 optics unless you need them.
