MOGlabs CEX - B1045;1046 Headboard; RF Coupling

34 Appendix B. Laser head board
B.1 B1045/1046 headboard
TheB1045andB1046provideconnectiontooneortwopiezos(slowhigh-
rangemulti-layerstackandfastdisc),andeitherpassiveNTCthermistoror
activeAD590/592activetemperature sensor. Noteonlyonetemperature
sensorshouldbeconnected,notboth.TheyprovideanSMA inputfordirect
diode modulation via an RFbias tee (see B.1.1 below).
Disc
Figure B.1: MOGLabsB1045andB1046laser headboardsshowing connectors
for laser diode, piezo actuator, temperature sensors, TEC and head enclosure
interlock.Connectors are Hirose DF59.
B.1.1 RF coupling
For theB1045/1046headboard,theSMAconnectorallows high-frequency
currentmodulationviaabias-tee. TheRFinputisACcoupled,with low-
andhigh-frequencylimitsofabout30kHzand2.5GHz(seefigureB.2).
CapacitorC4,either47nFor100pF,canbechangedtoadjustthelow-
frequency cutoff.For higherbandwidths, usean externalbias-tee suchas
theMini-CircuitsZFBT-4R2GW-FTbetweentheheadboardandthediode.