Tip:
Highlight text to annotate it
X
Now you can measure beams that are really large and are really high power, super fast.
If you work with beams that are very large;
if you work with high-power beams (on the order of tens of kilowatts);
if you work with an application that needs a very fast measurement (where, let's say,
one or two seconds is just far too long);
then you're probably aware of the challenges in measuring such beams.
Normally, thermopile-based sensors for measuring laser power have a response time of a few
seconds, and the larger the sensor, the longer the response time.
It's basic physics -- it takes time for the heat to propagate through the mass of the
disc.
Normally, thermopile-based sensors for measuring large laser powers get bigger and heavier
as they are designed for higher and higher powers.
Ophir's "10K-W" sensor, for example, which is designed for measuring up to 10 kilowatts,
weighs four and a half kilos (about 10 pounds), and has a response time of about three seconds,
which is not bad for such a large sensor, mind you.
One doesn't typically find sensors for much higher powers than this as standard items...
yet.
Ophir has recently announced a completely new patent-pending type of thermal sensor
that doesn't have any of these limitations.
It's based on different way of thinking about thermal sensing.
The heat flows axially (in the direction of the incident beam), rather than radially outward
from the center.
In a nutshell, the heat moves through a very small distance, and what this means for you
is:
One: Response time is about 50 milliseconds, instead of a number of seconds.
A possible application that comes to mind for this might be fast feedback for laser
power control.
Two: Very high powers can be handled, since the heat propagates only a few millimeters
until it reaches its way out, through the heat sink.
And three: A sensor based on this technology can be made very large, without having to
be massive.
Here, you can see a prototype of a sensor we recently produced.
It has an aperture of 200 millimeters by 200 millimeters, and can measure over 20 kilowatts
continuous power, or a single pulse of two kilojoules.
Here you can see a small OEM sensor that measures a few tens of Watts, with a 50 millisecond
response time.