J. Kissel, F. Clara Continuing along the design process for SPI, I asked Fil what we typically do for optical fiber "patch panels," where we want to modularize long optical fiber runs. He showed me this example of a fiber patch panel that uses off-the-shelf optical feedthrough parts. Note, as is specifically visible in IMG_4258.jpg, there is no optical element within the feedthrough. Hence, the feedthrough just serves the purpose of aligning the to connecting fibers for a (potentially lossy) brief fiber-to-air-and-back transition. This isn't the only way we do it; for comms fibers like what goes from the timing master in the MSR to the timing fanout in the CER, we do somethin like what's shown in IMG_4254.jpg. Alternatively, when optical fibers enter / exit a laser table (e.g. SQZT0 or the ALS ISCTEX or ISCTEY tables) we build our own labeled panel, that holds an off-the-shelf thorlabs feedthrough -- for example, the LO beam for the SQZ'er's panel is D1700147 which uses the Thor Labs part #ADAFC4.