MOGlabs CEX User Manual

36 Appendix B. Laser head board
B.2 B1047/B1240 headboards
TheB1047 andB1240 provide high-speedactive modulation of thediode
current. They use500MHz opampsandverylowlatencycircuitrytore-
ducephasedelaytoaround12nsfortheB1240. TheB1047allowsfor
closed-loop bandwidth of about 1.2MHz while the B1240 can achieve
about4MHz(inbothcases,withoutphaseadvance),whichishelpfulin
achieving sub-Hz linewidth reduction by locking to a high-finesseoptical
cavity. TheB1240alsoallowsdirect-groundconnectionorbuffered;the
latterisabout10%slowerbutreducesproblemswithground-loopnoise.
The B1240isnotsuitablefordiodeswithhighcompliancevoltage,typi-
cally diodes with wavelength below 600nm.
Note thatconnection tothe SMA input willreduce thediode current, even
if the control voltage is at zero.
C 5
C 4
R 4
R 7
C 6
R 5
R 6
C 11
R 12
D1
R 10
C 8
R 14
U 3
R
1
C 3
Q 1
R 2
C 1
C 2
R 3
R 11
P2
U1
P5
U2
R 13
C 7
R 9
SMA
P3
P4
P6
L1
L2
P1
ACDC
LED
Thermistor
Piezo1
Laser diode
TEC
+
–
+
–
+
–
+
–
+
–
Piezo2
C1
C6
C
7
R15
R3 R4
R6
R2
D1
R5
C5
R16
C2
R1
R14
C8
R17
C4
U1
R7
U3
U2
R10
R11
R12
R13
P6
P5
R8
RL1
R9
C3
SMA
P9
P10
P11
L2
P8
L1
ACDC
Buf Dir
LED
Thermistor
Piezo1
Laser diode
TEC
Piezo2
Figure B.3: B1047(left)andB1240(right)enhancedlaserheadboards.Jumpers
attopleftcanbeconfiguredforAC orDCcoupling. TheB1240hasanaddi-
tionaljumper“BufDir” forbuffered ordirect input,shownconnected forbuffered;
changetopins1and2fordirect.ModulationinputviaSMAconnector,sensitivity
2.5mA/V. Connectors are Hirose DF59.

MOGlabs CEX Specifications

General

Brand	MOGlabs
Model	CEX
Category	Measuring Instruments
Language	English