This electronic module is intended for stabilizing external cavity diode lasers to high-finesse external resonators in the research field of optical atomic standards. The device comprises two essential blocks – a fast feedback PID lockbox, and a slow PI lockbox. The lockbox allows reaching sub-Hz laser linewidths because it is built after the same schematics as used for sub-Hz stabilized linewidth laser which is described in paper by Alnis et al. in Phys. Rev. A 77, 053809 (2008). The key specifications and images of the device as well as graphs obtained during the operation are shown below.
Fast feedback branch
- 50 Ohm inverting and non-inverting inputs. Can be used as single ended or differential;
- Input signal range ± 1V;
- Input noise of amplifier 0.92 nV/Hz^1/2, 2.3 pA/Hz^1/2;
- 10 MHz proportional bandwidth (-3dB);
- Proportional gain switchable -30…+20 dB in 10 dB steps and using fine adjustment;
- Input to output delay time 13 ns.
Slow feedback branch
- Input impedance 10 kOhm;
- Input amplifier noise 3 nV/Hz^1/2;
- Low input offset drift 0.2 μV/degC;
- Proportional bandwidth 70 kHz(-3dB);
- Integrator low frequency voltage gain 70 dB;
- Output range ± 12 V. Output current ca 10 mA;