- Quantum Cascade Laser Starter Kit Instructions Manual

Starter Kit Instruction Manual Description 24
4.7 QCL pulser timing un it (T P G128)
4.7.1 Description
The QCL pulser timing unit is designed to control
the QCL pulser sw itching unit.
It provides TTL pulses on 50Ω on two indepen-
dent outputs. The pulse duration is adjustable from
0 to 200 ns. 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 op eration 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):+12 VDC
Output max current (for switching unit):150mA
Delay between pulses :
. . . . . . . . . . . . . . . . . . . . . . . .200 ns to 2.2 µs
. . . . . . . . . . . . . . . . . . . . . . 500 ns to 1 0.5 µs
. . . . . . . . . . . . . . . . . . . . . . .5.1µs to 105.1 µs
trigger and logic output signals: . . . 50Ω TTL
driver circuit (74128)
gate level : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TTL
Maximum duty cycle: 5 0% (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).
T
P
G
1
2
8
−
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5
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s
5
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1
0
5
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0
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2
0
0
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s
−
−
−
−
−
−
−
−
−
P
e
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o
d
−
−
−
−
−
−
−
−
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D
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0
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Fig.10: QCL pulser timing unit
Limitations
Caution !
The generator can not operate with a 200 n s 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