Santec TSL-710 - Page 45

Tunable Semiconductor Laser TSL- 710
6-9
Analog Input LF Mod. RF Mod.
Low-frequency modulation signal input
Specications
Modulation bandwidth: DC to 400kHz
Input level: 0 to –2V
Modulation depth: >50%/V (Typ.)
Input impedance: 4.7 kΩ
■
How to cancel
1. Remove the external modulation signal.
Inside the cover at the bottom of the front panel.
2. Set the source to Disable . “Ext. Mod” turns off on the screen.
Never apply voltage out of the input level range. Doing so may damage the device.
CAUTION
Set the source to Disable when modulation function is not used, in order to narrow
the spectral linewidth.
If coherence control is active, modulation setting is always set to “Ext.” and cannot
be changed to “Disable”. (Refer to “6-2 Coherence Control”)
NOTE
External modulation setting cannot be changed to “Ext.”, when coherence
control is ON. Please check coherence setting is set to OFF, before using
external modulation. (Refer to “6-2 Coherence Control”)
NOTE
It is recommended to use this function with closed loop wavelength control
stopped. Closed-loop wavelength control can be stopped by setting "0.00" with the
ne tuning function. Refer to "6-1. Fine-tuning” to cancel closed-loop wavelength
control”. When using this function without stopping the closed-loop wavelength
control, "WL.Err" may be displayed on the right side of the display. The wavelength
accuracy in this state is outside the product specications.
NOTE