Our Multi-ion Indium clock laser published in Optics Letters!

We developed an ultra-stable laser system at 946 nm for the interrogation of our multi-ion clock based on Indium ions. The demonstrated instability of 1.1x10-16 at 1 s ranks among the best instabilities achieved worldwide with ultra-stable lasers at room temperature. In addition, all key components have been replaced by FPGA-based digital electronics, thus achieving an easy configuration of the locking parameters. To reach an instability below the 10−16 level, we transfer the stability of a 1542 nm laser stabilized to a cryogenic silicon cavity exhibiting a fractional frequency instability of 4×10−17 at 1 s to the laser at 946 nm.

Link to the paper.