Pound-Drewer-Hall lock
In recent years the Pound–Drever–Hall technique has become a mainstay of laser frequency stabilization. Frequency stabilization is needed for high precision because all lasers demonstrate frequency wander at some level. This instability is primarily due to temperature variations, mechanical imperfections, and laser gain dynamics, which change laser cavity lengths, laser driver current and voltage fluctuations, atomic transition widths, and many other factors. PDH locking offers one possible solution to this problem by actively tuning the laser to match the resonance condition of a stable reference cavity.
The ultimate linewidth obtained from PDH stabilization depends on a number of factors. From a signal analysis perspective, the noise on the locking signal can not be any higher than that posed by the shot noise limit.[3] However, this constraint dictates how closely the laser can be made to follow the cavity. For tight locking conditions, the linewidth depends on the absolute stability of the cavity, which can reach the limits imposed by thermal noise.[5] Using the PDH technique, optical linewidths below 40 mHz have been demonstrated. [1]
Kazan
- solder minicircuits
- solder R22
- jumper 10 and humper 4 overlap
- change pin order for minicircuits chips
- files are stored in Projects/Astana/Electronics/
Parameters of the Calgary setup
| Parameter | Value |
| Optical Power on the detector | ~5.4 uW |
| Electronic power of the LO | -2 dBm |
| Electronic power of the RF | 2 dBm (specify) |
Make sure that frequency of scan is low ~1Hz, since in the circuit ver LPF are installed.
- ↑ Kessler T, et al. (2014).
