Many applications require robust optical methods based on the production of identical interferometers. These include, for example, quantum key distribution (QKD) based on the BBM92 protocol with phase-time entanglement or white light interferometry methods or certain OCT

procedures.



We have developed a method to build and operate any number of identical fiber-based Michelson interferometers at low cost. In our set-up, no expensive electro-optical components are required for phase adjustment, which leads to significant time and cost savings in production. This makes these interferometers economically attractive, for example for star-shaped QKD networks with the Time-Bin Entanglement Protocol,

economically interesting.