NKT Photonics Koheras ADJUSTIK, Product Manual

Page: 42 / 105

External cavity stabilization (ADJUSTIK X15)
42
depicts a general layout of the devices in a Pound-Drever-Hall configuration
used with an X15 ADJUSTIK.
Figure 17 ADJUSTIK X15 in Pound-Drever-Hall configuration
Setting up external
cavity stabilization
Follow the steps below to configure and enable external cavity locking:
1. Enable external modulation (see
“Modulation Source” on page 68
).
2. Configure the wavelength modulation input as DC coupled (see
“Modulation
Coupling” on page 69
)
3. Configure the laser to operate in narrow modulation range (see
“Modulation
Range” on page 70
).
4. Turn wavelength modulation on (see
“Turning on wavelength modulation” on
page 71
).
5. Set the update interval (see
“Integrating update interval” on page 70
).
Once enabled, the laser constantly adjusts its wavelength so that the Pound-
Drever-Hall loop results in a 0 V differential applied at the Wav/- input
pins.
When using external cavity stabilization, differential input is preferred to achieve
the lowest noise performance.