3 ms·

Hard to tell but they are likely couplers for light from the lasers and electrical interconnects you can sort of see some grating at the ends. The 4x ones are l

by nimish 4y ago

Hard to tell but they are likely couplers for light from the lasers and electrical interconnects you can sort of see some grating at the ends. The 4x ones are likely for 4x laser assemblies like in QSFP (Quad) or for cases where you want to TX rx over multiple fibers. The bright cubes are the laser chips that are bonded on top of the quartz, since native silicon lasers aren't practical. That whole illustration looks like a bunch of chips in a wafer maybe with testing and monitoring patterns included. Looks like some other stuff like modulators in the top right of the square. Maybe a test run for process control? Edit: yeah the cubes are definitely laser dies, fig 2 shows the process. The patterns are the couplers and such to get the light in without losses and at the right direction.

nkurz 4y ago
Hmm, if this is right then some of the illustrations might not be showing quite what is intended. We assumed that the rectangular gray structure in the upper left of each square chip was the laser. All the other illustrations (lower in the article and in color) show different ways these can be attached, one per chip. If the bright yellow blobs on the smallest squares are also lasers, something is off. In some ways it's fascinating that illustrations for technical articles work at all. Usually there are two layers of people who may not understand the tech between the artist and the scientists, and no direct communication allowed. Choices often come down to Googling to find earlier publications online by the same group, and hoping those earlier illustrations were accurate.
- tarlinian 4y ago
  The tiny yellow blobs are the bonded lasers, so the locations of the bonded lasers in the subsequent figures are incorrect but still get the point across. This page from IMEC has a video actually showing some of the process. (The image at the top is from a press release from them about successfully doing flip chop bonding of lasers.) https://www.imec-int.com/en/silicon-photonic-ICs-prototyping https://www.imec-int.com/en/silicon-photonic-ICs-prototyping
- nimish 4y ago
  I think it still gets the point across, namely that you have to stick one chip on top of another, but it's a little wild they didn't at least give the artist labeled notes and legends

by nimish 4y ago

nkurz 4y ago

Hmm, if this is right then some of the illustrations might not be showing quite what is intended. We assumed that the rectangular gray structure in the upper left of each square chip was the laser. All the other illustrations (lower in the article and in color) show different ways these can be attached, one per chip. If the bright yellow blobs on the smallest squares are also lasers, something is off. In some ways it's fascinating that illustrations for technical articles work at all. Usually there are two layers of people who may not understand the tech between the artist and the scientists, and no direct communication allowed. Choices often come down to Googling to find earlier publications online by the same group, and hoping those earlier illustrations were accurate.

tarlinian 4y ago
The tiny yellow blobs are the bonded lasers, so the locations of the bonded lasers in the subsequent figures are incorrect but still get the point across. This page from IMEC has a video actually showing some of the process. (The image at the top is from a press release from them about successfully doing flip chop bonding of lasers.) https://www.imec-int.com/en/silicon-photonic-ICs-prototyping https://www.imec-int.com/en/silicon-photonic-ICs-prototyping
nimish 4y ago
I think it still gets the point across, namely that you have to stick one chip on top of another, but it's a little wild they didn't at least give the artist labeled notes and legends