285 nm-Laser (S-MOT)

The 285 nm Laser consists of a two-stage frequency doubled, raman-fiber-amplifier MOPA. The raman-fiber-amplifier is seeded by a diode laser.

Laser-Diode current: .. mA

Seed power (is displayed in the FLPM RMU CCT 1.1.0.0 program): ~ 20 mW

Change values

Turning on the Laser

Enable main-switch. Set key to standby.

Wait for the LED to change the color from orange to green to orange (~15 seconds after turning on). Turn the key now.

Start the program FLPM RMU CCT 1.1.0.0 and select the checkbox of Laser Enable.

The Power Setpoint must stay at 0.500 W

Optimize fiber coupling to Iodine Spectroscopy. Transfer-efficiency > 70%

Change Power Setpoint for 285nm SHG operation

2 - 2.500 W for 100-150 mW directly after 285 nm SHG.

Do not exceed much more than 3.5 W

Locking to Iodine-Spectroscopy

Start DigiLock-Module Server and connect to S-MOT-Laser

Push Scan on and AutoLock

Change the Offset Value to 0 V

Change the frequency with the piezo on the toptica rack electronics to be close to the iodine resonance (check with wavemeter)

Change the Setpoint (under AutoLock) to be in the middle of the error signal. Check, if the crosshair snaps to the slope.

Move the crosshair to the second slope, rightclick on press PID: Lock to Slop.

Lock-Paramters

Add parameters

Lasersystem - Typical power values

Kürzen und nur das wichtigste angeben

The 285nm SHG was build by Jan Friebe and is described in his diplomathesis.

570 nm-Laser

Outputpower after cube to 285 nm-SHG: ~ 1.2 W @ 2.5 W

Operationpower: < @ 3 W

Max outpupower: ??? W @ ??? W

Iodine spectroscopy

Infront fiber: ~ 38 mW @ 0.500 W

After fiber: ~ 29 mW @ 0.500 W (= 400 mV @ 0.500 W) [efficiency ~ 70 %]

Infront fiber: ~ 220 mW @ 2.500 W

After fiber: ~ 160 mW @ 2.500 W (= 2 V @ 2.500 W) [efficiency ~ 70 %]

285 nm-SHG

Outputpower: ~ … mW @ 2.000 W

Outputpower: ~ 100 mW @ 2.500 W

Power for photodiode: ~ … müW

Stabilized power (infront AOM): 80 mW

Power infront the AOM in … order: 80 mW

Power behind the AOM: 43 mW @ 2.500 W (efficiency ~ 50 %)

Power for the Zeaman-slower: … mW

Power behind the mystical mirrow: … mW