IPL vs Laser
Both laser and intense pulsed light (IPL) use light to heat hair follicles and prevent regrowth. The key difference is the light source that is used
Both methods target the melanin in the hair follicle and permanent results can be expected from both.
Laser is a single concentrated wavelength that travels down the hair follicle via the melanin (where the pigment that colours your hair). it only targets on one small area.
IPL has a high-intensity, visible, broad-spectrum pulse of light, generally in the visible spectral range of 400 to 1200 nm that emits multiple wavelengths to cover a wider area of skin. Various cut off filters are commonly used to selectively filter out shorter wavelengths, especially potentially damaging ultra violet light. The resulting light has a spectral range that targets specific structures and chromophores (e.g. melanin in hair, or oxyhaemoglobin in blood vessels) that are heated to destruction and reabsorbed by the body. IPL shares some similarities with laser treatments, in that they both use light to heat and destroy their targets. But unlike lasers that use a single wavelength (colour) of light which typically matches only one chromophore and hence only treats one condition, IPL uses a broad spectrum that when used with interchangeable filters, allowing it to be used against several conditions. This can be achieved when the IPL technician selects the appropriate filter that matches a specific chromophore.
Advantages of IPL
IPL is unlikely to damage the top layers (epidermis) of the skin because it uses several wavelengths of enhanced energy to treat the skin, unlike other laser treatments that normally use an intense all-at-once light, causing more side effects and it has higher risk of burning darker skin.
IPL is known for rejuvenating skin. It corrects and evens skin tone.
Most people do not know this. If the intensity of the light is low, it can have an adverse effect on hair growth!!
It is very rare for the hair growth to worsen during treatment. However, if the heat in the follicle doesn't reach a certain temperature, then the follicle has been hypothesised due to the low frequency of the treatment, where the hair can be grown back thicker after laser. This is very rare, but it can happen! Your less likely to have that with IPL because of the broad-spectrum light. Technician can up the intensity, without burning the skin.
You do need to do your research and find what suits your skin type. Make sure the machine is approved. Don't be afraid to ask questions.