Datalogic Arex 400 - Laser Marker Operations

MOPA Fiber Laser
110 Arex™ 400
Laser marker operations
The Arex™ A20-X6X is a very flexible laser marker based on a master oscillator
power amplifier (MOPA) architecture, that allows the user for a wide selection of
pulse profiles and pulse repetition frequencies.
Depending on the Pulse Profile selection and pulse Frequency the laser will gen-
erate pulses with stable output energy/peak power or stable laser average
power.
The following picture illustrates the pulse peak
power and laser average power
dependence on the frequency, for the entire operating frequency range.
Figure 1: Typical average power (dash line) and peak power (solid line) dependence on the
frequency for the 8 ns the pulse profile
As shown, when the laser is operated with Frequency above the pulse transition
Frequency (fT) (typically 200 kHz for the 8 ns pulse profile) the average power
(dash lines) remains constant while the pulse energy/peak power (solid lines) will
change. This is the more common operating region for most applications. Data-
logic designates this region as the “Constant Average Power Region”.
A characteristic of the Datalogic Arex™ A2
0-X6X laser marker is that user is
allowed to operate the laser at pulse repetition frequencies that can be reduced
down to 20kHz and up to 500kHz (depending on Pulse profile selected). If the
laser was allowed to operate down to lower frequencies without any restriction,
the pulse energy would keep increasing until reaching non-linear thresholds that
would result in laser performance degradation or even self-destructive failure.
To prevent the laser marker from reaching these undesired conditions, while
allowing the user to set the laser pulse frequency freely, Datalogic implemented
laser internal safety controls to allow stable pulse peak power/energy below the
transition frequency (fT).
Thus, within the extended operating region below the transition frequency, the
pul
se energy/peak power will remain constant (as illustrated in the figure above).
Datalogic designates this extended region as “Constant Energy/Peak Power
Region”. This region is ideal for applications that require changing of the laser
pulse frequency while keeping pulse energy or peak power constant.
The maximum frequency of operation (fmax) depends on the pulse profile set-
ting: for Pulse Profiles 4 to 100ns, fmax is 50
0kHz; for Pulse Profile 200ns the
fmax is 250kHz, and for Pulse Profile 250ns fmax is 200kHz.