COOLING REQUIREMENTS AND POWER CONSUMPTION
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14
4
Confirm that the laser has adjusted its power such that the external power meter now reads ###mW within a few
mW.
5
If necessary, repeat steps 3 and 4 until the calibration agrees.
6
Once accepted, type the command WRITE to store the new calibration.
Important Note:
Take extra care to remove back-reflections to the laser. Any magnitude of back reflection may
disturb the resonant cavity and will affect the APC feedback control loop.
Cooling Requirements and Power Consumption
Cooling Requirements
The laser has a characteristic warm-up period before it reaches specification; this time depends partly on the heatsink to
which it is attached. However, the typical warm-up time is 10 minutes from switch on.
In order for the laser to perform to specification, it must be adequately heatsinked. Operating the laser on an inadequate
heatsink will adversely affect its stability and may result in thermal shutdown of the laser head or reduction in beam
power. In normal laboratory conditions, a heatsink with dimensions 400 x 400 x 10 mm should be suitable for the laser to
operate in accordance with its specifications. Depending upon environmental conditions and power of the laser, additional
cooling aid might be required (e.g. TEC, forced air cooling, water cooling). For further information on heatsinking your laser
system, please consult your sales representative who may be able to provide a heatsink solution.
gem laser head
Once the maximum operational temperature for the laser head (see Section 1) has been reached, one of two things will
occur: To ensure the correct cooling arrangement the flow direction should be as follows:
1
The current to the diode will immediately be switched off and the laser system will need to be restarted once the
temperature has been restored to normal
2
If de-rating is enabled the current will gradually be reduced to zero in order to try to allow the laser head
temperature to stabilise. If the current does reach zero the system will need to be restarted. The effects of de-
rating are shown in the table below:
Current Laser
Head/Laser OVERTEMP
LED
Colour of Laser and PSU
text on LCD
Set by user
Off
Orange
Begins to de-rate
Flashes
Flash Red and White
Reduced to zero
On
Flash Red and White
smd24 PSU
A similar arrangement occurs for the PSU once the maximum operating temperature (see Section 1) has been reached.
Important Note
: The indicator LED in this instance is marked ‘PSU OVERTEMP LED’.
Power Consumption
The power consumption shown is that which is drawn at the plug from the mains supply in both the Maximum and Typical
states. The Maximum power will usually be drawn at start up and the typical power is when all temperatures are stabilized,
