Relative frequency stabilization of extended-cavity diode lasers for the re-pumping of Ca ion

Traditional stabilization methods of multiple lasers using Fabry-Perot interferometers need several optical devices for combining and separating the laser beams. Therefore, laser beams with similar frequencies are difficult to stabilize because they cannot be easily optically separated. For this reason, we built a new laser frequency stabilization system which does not require the optical separation of the laser beams. We achieved the frequency stabilization of two extended-cavity diode lasers using an FPI within ±5 MHz per hour.