Everything you Ever Wanted to Know on Laser Therapy!

Pulsed vs. continuous wave lasers: what’s the difference?

In general, laser diodes are either continuous wave or pulsed. The continuous wave (CW) diodes emit laser energy continuously, hence the name.

Pulsed diodes emit a radiation impulse with a high amplitude (intensity) and duration which is typically extremely short: 100-200 nanoseconds. Continuous wave lasers produce a fixed level of power during emission.

Although lacking the high peak power of a “true” or “super” pulsed laser, most continuous wave lasers can be made to flash a number of times per second to simulate pulse-like rhythms by interrupting the flow of light rapidly as in turning a light switch “off” and “on.” True or super pulsed lasers, as the names imply, produce a brief high-power level light impulse. It is the high-power level achieved during each pulse that drives the light energy to the target tissue.

The peak power of a true or super pulsed laser is quite high compared to its average pulse power. By using true or super pulsed lasers, one is able to more effectively drive light energy into tissue. The laser and electronic technologies required to use pulsed diodes are more advanced and the diodes themselves are more expensive than the continuous wave diodes. This is why over 90% of the therapeutic lasers in the North American market are low power continuous wave lasers. Some of these lasers provide power literally at the same level as an inexpensive laser pointer costing around $30.