Dynamic Laser Frequency Control
Tunable Frequency-Offset Locks
Laser Frequency control in the UV (313nm) to NIR (1100nm) optical range is a key element in the implementation of high-precision Quantum technologies. QUBIG’s broadband phase modulators (TWP-series) and their matching drivers (QDB) can be equipped with nifty features to provide a robust and versatile frequency offset lock over a span of up to 10 GHz between a laser and a stable frequency reference, such as an optical cavity, another laser (master), or an atomic transition.
FREQUENCY OFFSET LOCK
Working principle
QUBIG’s TWPM and matching drivers offer a unique dynamic tool for the control of a laser’s frequency relative to a reference. By comparing the sideband generated to the selected reference, it is possible to continuously tune the laser frequency up to 20 GHz away from the reference.
QUBIG SOL-Series can be used for three widely used frequency references: optical cavity, reference laser, and atomic transitions.
OFFSET TO AN OPTICAL CAVITY
Sideband Offset-Lock to FPI
The SOL-system was developed to lock the high-frequency sideband onto an optical cavity. This is achieved by modulating the RF power to create additional low-frequency sidebands and generate a Pound–Drever–Hall error signal. The TWPM driving frequency provides a variable offset up to 20GHz between the cavity and the laser.
OFFSET TO A MASTER LASER
Sideband Offset-Lock to stable laser
The MSL-series contains a built-in broadband phase modulator that generates sidebands onto the reference laser. A second laser is then locked to the reference sideband with the frequency offset being defined by the TWP’S driving frequency.
OFFSET TO AN ATOMIC TRANSITION
Sideband Offset-Lock to DFSS signal
The TWPM series in combination with e.g. QUBIG’s spectroscopy modules for Rb (780nm and 420m) and Cs (852nm) allow to lock a sideband to a Doppler-free Saturated Spectroscopy (DFSS) signal providing a variable frequency offset to an absolute frequency reference.
