Quantum Instruments Cascade Laser Starter Kit - Manual (Page 25)

Starter Kit Instruction Manual Description 24
4.7 QCL pulser timing unit (TPG128)
4.7.1 Description
The QCL pulser timing unit is designed to control
the QCL pulser switching unit.
It provides TTL pulses on 50Ω on two indepen-
dent outputs. The pulse duration is adjustable from
0 to 200ns. The interval between pulses can be ad-
justed between 200ns and 105µs in 3 ranges.
A TTL level Gate in input and Trigger out
output have also been included. The trigger pre-
cedes the output pulse by about 100ns.
The QCL pulser timing unit includes the +12VDC
power supply needed by the QCL pulser switching
unit by means of a Lemo 00 connector with the
+12V on the centre wire.
! Warning !
Although the pulser system is capable of
delivering pulses with lengths up to 200 ns,
and duty cycles up to 50%, the laser may not
withstand this! The laser shall only be op-
erated under conditions as specified in the
datasheet or by Alpes Lasers directly: all
other operation may result in destruction of
the laser and loss of warranty.
4.7.2 Specifications
Voltage : . . . . . . . . . . . . . . . . . . . . . . . . .220V-240V
Frequency : . . . . . . . . . . . . . . . . . . . . . 50Hz-60Hz
Output voltage (for switching unit):+12VDC
Output max current (for switching unit):150mA
Delay between pulses:
. . . . . . . . . . . . . . . . . . . . . . . .200 ns to 2.2 µs
. . . . . . . . . . . . . . . . . . . . . . 500 ns to 10.5 µs
. . . . . . . . . . . . . . . . . . . . . . .5.1µs to 105.1 µs
trigger and logic output signals: . . . 50Ω TTL
driver circuit (74128)
gate level : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TTL
Maximum duty cycle: 50% (if larger cycles are
needed, the LDD100 should be fed by an exter-
nal 12V power supply, not the one provided in the
TPG128, or else the fuse in the TPG128 may blow).
TPG
128
−TT
L P
ulse
Gen
erato
r
OF F
ON Pow
er
0.2 to 2
.2 µ s
0.5
to 1 0.5 µ s
5 to
105 µ s 0 to
200 ns
−−−
− −
−−−
−Pe
riod
−−−
−−−
−−−
−D ura
tion
−
Gat
e IN
Trig
OU
T
Ou t 1
Ou t 2
50 ohm s
50 ohm s
50 ohm s
ma x 6 0m A
+12
V 0 V
Fig.10: QCL pulser timing unit
Limitations
Caution !
The generator can not operate with a 200 ns long
pulse at a 200ns repetition interval, therefore it is
limited in duty factor.
The following limitations apply:
T=400ns: . . . . . . . . . . . . . . . . . . . . t max = 200ns
T=300ns: . . . . . . . . . . . . . . . . . . . . t max = 200ns
T=250ns: . . . . . . . . . . . . . . . . . . . . t max = 150ns
T=200ns: . . . . . . . . . . . . . . . . . . . . t max = 100ns