A High-precision Laser Diode Driver for MDI-QKD System

Measurement-device-independent quantum key distribution (MDI-QKD) System is based on the decoy state method and a time reversed Einstein-Podolsky-Rosen (EPR) protocol. Stringent requirements for the central wavelength, line width and optical power of the laser source are required in MDI-QKD. In order to satisfy above requirements, this work proposes a high-precision laser diode (LD) driver, which consists of a temperature control module and an optical power control module, moreover, the outgoing laser needs to be injection locked first. Through laboratory tests, the wavelength jitter of the laser is 0.37pm, the −3dB spectrum width is 0.0170nm and the optical power fluctuation reaches 0.01dB. The results indicate that the designed LD driver meets the requirements of MDI-QKD.