THORLABS SPDC810N User Manual page 10

Narrowband Photon Pair Source
3. Check the emission status of the device on the bottom of the screen. It should show "Off" prior to enabling
the pump source.
4. Make sure the interlock input on the back panel is short‐circuited. (See Section 6 for detailed instructions.)
5. Press and release the ENABLE switch to activate the SPDC810N. There will be a 3 second delay before the
pump laser powers up. During this time, the ENABLE indicator will light up and blink.
6. Adjust the pump current set‐point starting from 0% to the desired value by pressing the adjustment knob
once. The "%" sign blinks in the adjustment mode, and it times out after 5 seconds. The knob must be
pressed again after the time‐out in order to make additional adjustments to the pump current set‐point.
The unit is now producing photon pairs and is ready to use.
Adjusting the Photon Pair Rate and Wavelength Degeneracy

Photon Pair Rate ‐ The photon pair rate can be controlled by varying the pump current set‐point. The pair
rate specifications represent the performance at max operating set‐point (100%) and decreases as current
is lowered.

Wavelength Degeneracy ‐ Adjusting the temperature of the crystal will slightly change the output
wavelengths of the signal and idler. This may be needed for applications requiring a more precise degree
of wavelength degeneracy.
Turning the SPDC810N Off

Disabling the photon emission ‐ The pump laser, and therefore photon pair output can be turned off by
pressing and releasing the ENABLE switch. The pump diode temperature will be maintained even when
the source is disabled.

Power Down ‐ When completely powering down an enabled unit, first press and release the ENABLE
switch and then press the POWER push‐button switch, which will turn OFF the entire unit. Anytime the
unit is turned OFF and then turned back ON, the pump laser will be disabled until the ENABLE switch is
pressed. The pump current set‐point goes back to 0% after each power cycle. If the unit is not being used
for an extended period of time, it is recommended to turn off the AC power using the switch located on
the back panel of the instrument.
Page 8
Chapter 4: Operation
TTN271994‐D02