Plugging in the thermal feedback BNC cable to the laser reduced the DC voltage of the green PDH photo diode from 3.12 V to 1.5V off resonance.
The power emitted by the laser was the same as in the case without that cable. Note LT, i.e. measured crystal temperature, of the laser show a
different value when the BNC is connected, but the manual clearly states that this display does not work properly if a cable is connected to the
slow BNC plug, an offset is added.
The power of the 532nm light behind the SHG oven has been reduced from 1mW to 0.4mW. I changed the crystal temperature such that the power
of the green light is 1mW. With this new temperature setting the laser can be locked again.
| |
w/o BNC cable at slow plug |
w/ BNC cable at slow plug |
| T (°C) |
29.776 |
29.776 |
| LT (°C) |
39.2 |
48.4 |
| 1064nm power (mW) |
440 |
448 |
| Temp. at TC200 (°C) |
35.7 |
36.4 |
| 532nm power in front of Isolator (mW) |
1.0 |
1.0 |
|