THORLABS CLD101 Series, Operation Manual

Page: 18 / 92

© 2018 Thorlabs 16
CLD101x
RF Modulation via SMA RF input
The CLD1010LP / CLD1011LP laser mount has an RF input for modulating the laser with an
external RF source from 200 kHz to beyond 1 GHz. This is a 50 Ω input that is AC-coupled directly
to the laser through the Bias-T network. To calculate the desired RF power to modulate the laser,
determine the amount of modulating current needed from the laser manufacturer’s data sheets and
use the following calculations:
RF voltage = LD modulating current ×50
W
It is strongly recommended that you start off conservatively by a factor of 10 below the calculated
modulating voltage and slowly bring the RF power up until the desired depth of modulation is
reached. Use the CLD1010LP / CLD1011LP to establish the DC operating point of the laser.
Warning
The RF input is directly coupled to the laser. Any excessive transients or noise will be coupled into
the laser and may cause the laser to be overdriven. Also, the laser can be easily overdriven if
excessive RF power is applied to this input. Use the RF modulation input with care to avoid
damaging your laser.