How to Measure High Powered Laser Pointers

Lasers are also used in surveying.

Laser pointers are useful products of modern research into ever more compact and powerful laser technology. Whether being used to direct students' attention to a slide, point out an important feature on a model or piece of machinery, or serving as a guide for setting up optical equipment, laser pointers are an indispensable tool. One common use is as a stand-in for a high-power laser when setting up the mirrors and lenses of an optical system on a lab bench. In this role, it can be useful to know the power and energy output of the laser, both to protect sensitive equipment and to act as a calibration tool for sensors.

Things You'll Need

• Laser pointer
• Energy meter
• Power meter
• Desktop computer

Instructions

1. Place the energy or power meter wherever it is convenient to do so. For instance, if you were working on an optical bench you would attach the device to the top of a bench stand screwed into the table or secured with a magnet. Otherwise, you could use double-sided tape to keep the meter secured. It is important that it is securely fastened to whatever surface it sits on to reduce the chance that the beam could wander off the sensor-patch.

2. Plug the meter in to a desktop computer. Most energy and power meters connect via a USB port and all will come with a disc containing the software needed to interface with the sensor. This software should be installed before you attempt to connect the the energy meter and, depending on the instructions that came with your piece of equipment, may need to be activated before the connection is made.

3. Zero the meter to account for the light already present in the room. This is usually achieved via a button or setting on the software that came with the meter.

4. Mount the laser in a lab clamp or affix it to a surface using tape. Turn it on and make sure that the beam is falling on the light-sensitive patch of the energy or power meter. You can expedite this by taping a piece of paper over the front of the meter and using the spot of light produced by the laser to direct it onto the detector patch. When centered, remove the paper, being careful not to disrupt the position or orientation of the meter.

5. Note the readout on the computer screen, showing the energy or power output of the laser pointer.

References

• NASA: Measuring the Electromagnetic Spectrum

Resources

• Optical Power and Energy Meters