13 Feb 2007 Photon’s NIST-traceable High-Power NanoScan measures focused CO2 laser beams up to 5kW as well as Q-switched lasers and other higher frequency pulsed lasers. Ideal for measuring lasers operating with pulse width modulation (PWM) power control. NanoScan for High-Power Beam Applications
Photon’s High-Power NanoScan can measure focused CO2 laser beams up to 5 kilowatts. The High-Power NanoScan is equipped with a pyroelectric detector with copper slits and drum. A cooling fan mounted on the scan head body provides additional heat management. With the new "peak connect" algorithm and the software controlled variable scan speed, the High-Power NanoScan is ideal for measuring lasers operating with pulse width modulation (PWM) power control. Measurement of
Q-switched lasers and other higher frequency pulsed lasers is also possible using this feature.
What Can be Measured?
Measuring high-power beams can be tricky. The lasers have the potential to damage the scan head, and any reflected light can be dangerous to both the operator and the surroundings. The High-Power NanoScan can measure these beams because it uses a combination of highly reflective components with high thermal dissipation capability. It is important to manage the reflected beam so that it neither reenters the laser cavity nor sends stray beams into the surrounding area. The scan head is designed to make short duration measurements to avoid excessive heating of components. The head should be only in the incident beam for 10 to 60 seconds depending on the power levels to prevent excessive heating of the components. The High-Power NanoScan scan head has been shown to be able to handle power densities of 3.2MWcm-2 at 10.6mm, the power density of a 200mm beam at 1kW. At the shorter wavelengths of the other common industrial lasers, Nd:YAG and DPSS, the upper limits are a little less, due to the slightly lower reflectivity of the components at wavelengths around 1000nm. Visible and UV lasers can also be measured, but these will have lower limits yet.
Measuring Pulsed Lasers
The actual energy per pulse is an important consideration for pulsed beams. Individual pulses may damage the scan head, even when the average power falls within the safe region of the operating space chart. For this reason it is necessary to understand the limits in Joules for lasers that use pulsing to increase the delivered energy, most commonly the Q-Switched laser. PWM lasers can be treated as CW for power/energy considerations.
For more information on measuring pulsed lasers, refer to Photon's Application Note, Measuring Pulsed Beams with a Slit-Based Profiler. Available on the Photon website.
|
