b) Optical Cavities
An alternative approach of measuring a laser´s frequency is to link it to the geometrical properties of an optical cavity. The most common type for this purpose is the
c) Frequency Comb
Another way to stabilize a laser´s phase or frequency is to compare it to a stable light source. A tool which has been developed for exactly this purpose is the frequency comb. Its
TOPTICA Solution
The TOPTICA DFC CORE + is a frequency comb which is based on Difference Frequency Generation (DFG), i.e. the carrier-envelop offset is passively fixed to \(f_{CEO}=0\). It is
There are various ways to lock a laser to another optical reference. Here, the general principle of a phase lock to an optical reference will be described. The optical reference can e.g. be a second
The PD signal is a function of the phase difference between the laser light and the optical reference under consideration. This signal is only constant if the frequency difference between the laser
TOPTICA Solution
TOPTICA offers a complete solution for locking a laser to a TOPTICA frequency comb. The DFC BC is an advanced beam combiner module. It offers the possibility to adjust the power
An offset phase lock to a second cw laser can easily be implemented using TOPTICA´s FALC pro which will be presented in more detail in the application note “PID Feedback Controllers”. For
The most straightforward way to generate an error signal is to send part of the laser light through the cavity and measure the transmission with a photodiode behind the cavity. Analogous to the
The implementation of side-of-fringe locking using the cavity reflection is straightforward, but has the disadvantages described above. Instead, we will focus on a scheme known as the
TOPTICA Solution
With the PDH/DLC pro, TOPTICA offers a module for the electronic generation of a PDH signal. This includes an RF signal e.g. for driving the EOM. The PD signal recording the