IPL and Laser both are methods used to remove unwanted hair and both of these are used to remove hair permanently. Yet there are some differences between them which can be summarized as follows:
IPL (Intense Pulsed Light) also called Photoderm, is a computer based machine. Just like a camera's flashbulb, Photoderm too uses bright light. Its light works similar to a laser and for the purpose to remove unwanted hair. However, there are still many differences between laser and IPL due to which IPL is gaining popularity day by day.
The largest difference between IPL and lasers is in the physical composition of the apparatus. For one, laser light is coherent whereas IPL is not. This means that in IPL the light waves can interfere with each other and either increase or decrease the power of the wave. The laser light strength is always the same. Laser light is also monochromatic and collimated whereas IPL is not, which means that the wavelengths are of the same frequency and travel in the same direction. Therefore, the physical composition of lasers means that it is not easy to treat a person with varying colors of hairs; whereas IPL can treat a wide variety of hair color. IPL has the power to penetrate to various depths into the skin as it has a multitude of wavelengths .. As the laser's light is of the same wavelength it only penetrates to the same depth with each beam and hence has to be adjusted for each hair color ; this can be inconvenient for people with multi-colored hair.
Due to their wavelengths, their effectiveness too differs. Laser is limited to hair removal only whereas IPL not only removes facial hair or unwanted hair from any part of your body, but it also treats pigmentation on face, chests and hands and sun burnt skin. IPL also diffuse redness found on the face or chest which is not possible with laser. Therefore, IPL has a wider range of uses for the cosmetic industry.
Another major difference between IPL and laser is the pain which you get. The pain varies from person to person; however, laser light typically gives you a little more pain than the IPL. Lasers may give you strong pinching feeling. If your hair is dark you will experience even more pain. With IPL you generally feel less pain but you still get very light pinching feeling. This difference in pain is usually put down to the continuous concentration of a wavelength meeting the same spot on the skin for a long period.
IPL is effective in terraating a greater number of skin types IV (1-5); whereas laser is only suitable to treat skin types I -IV (1-4). IPL treatments are considered to be shorter than laser treatments because IPL 'heads' are up to eight times larger than lasers and so cover more area at a time. IPL also causes less damage to the surrounding skin than lasers. You are more likely to be scarred (despite still uncommon) with laser treatment than with IPL. Further, the risk of pigmentation to the skin after using IPL is much lower than lasers.
It is worth speaking to people who have undergone these methods to understand the process, costs, results and pain experienced. Only then should you undertake one of these methods.