Low Noise VCSEL Driver for SERF Atomic Magnetometer

A new type of VCSEL (Vertical-Cavity Surface-Emitting Laser) which uses Pt1000 as a temperature sensitive component and non-magnetic heating membrane as a temperature actuator is designed for SERF (Spin-Exchange Relation-Free) atomic magnetometer, which can decrease the magnetic interference produced while heating or cooling VCSEL. Therefore a low noise driver for this kind of VCSEL is necessary. A driver for the novel VCSEL is designed in this paper. The output current is adjustable from 0 to 4.5 mA, and RMS (Root Mean Square) noise of current is less than 80 nA. The operating temperature of the VCSEL is adjustable between 30-110 °C and RMS noise of temperature is less than 0.6 mK. So that it can be ensured that the VCSEL outputs a laser with stable optical power and wavelength.