The technology
How IPL and DPL machines work
A laser emits one wavelength. An IPL handle fires a xenon flash lamp that emits a broad spectrum, roughly 400 to 1,200 nm, and a filter in front of the lamp blocks the wavelengths below a cutoff so the pulse that reaches the skin starts at, say, 560 nm or 640 nm. That is why one IPL console can treat several targets: a lower cutoff for vascular redness, a mid cutoff for pigmentation, and a higher cutoff for hair, where melanin in the follicle absorbs the longer wavelengths.
DPL narrows the band further. Instead of a single cutoff filter passing everything above it, a DPL filter passes a defined window, which concentrates the energy where the target absorbs it and reduces the energy wasted on the rest of the spectrum. The DR10 and DRT10 use gemstone crystal filters, six on the DRT10, each matched to a treatment: hair, pigmentation, redness, and a near infrared window used for photobiomodulation sessions.
Pulsed light vs laser
- Energy density. A laser concentrates all its output at one wavelength; pulsed light spreads it across a band. For hair removal a diode or alexandrite laser is faster and works on a wider range of hair and skin types. See Diode Laser Machines.
- Versatility. Pulsed light treats hair, pigment and redness from one handle by changing the filter; a laser needs a different source for each.
- Skin types. Broadband light is absorbed by epidermal melanin as well as the target, so IPL and DPL are used on lighter skin types and with caution on tanned or darker skin. Contact cooling on both systems protects the surface.