Abstract: A pulsed laser skin treatment device is for laser induced optical breakdown of hair or skin tissue. A feedback system is used for detecting a feedback system based on light and/or sound/and/or contact force or pressure. The feedback signal is used to determine whether a pulse was in the tissue or outside the tissue. With these data an effectiveness of the treatment can be determined which can be provided to a user.

Abstract: A pulsed laser skin treatment device is for laser induced optical breakdown of hair or skin tissue. The device has a light exit window to be placed against a surface to be treated such as skin during use. A feedback system is used for determining a state of contact between the light exit window and the surface. To this end the feedback system is capable of detecting a feedback signal representative for the state of contact. If the feedback signal or the state of contact is such that the risk of skin surface or device damage by the device operation is too high, the user or the device has a way to interrupt the treatment or to reduce light output to reduce or eliminate this risk.

Abstract: A pulsed laser skin treatment device is for laser induced optical breakdown of hair or skin tissue. A feedback system is used for detecting a feedback system based on light and/or sound/and/or contact force or pressure. The feedback signal is used to determine whether a pulse was in the tissue or outside the tissue. With these data an effectiveness of the treatment can be determined which can be provided to a user.

Abstract: The invention provides a hair treatment device (40) comprising a detector (10) for detecting a hair (22) near a skin surface (21). The detector (10) comprises a light source (11) for generating a light beam (31) with an initial polarization direction, a polarization modulator (32) for time-dependent modulation of the polarization direction of the light beam (31) between at least a first polarization direction and a second polarization direction, optical elements (14, 16, 17, 18) for focusing the light beam (31) at the hair (22) near the skin surface (21), and a polarization-sensitive light-based detection unit (13) for detecting light interacted with the hair (22) or the skin surface (21) and for discerning when the interacted light has a polarization-direction component different from the initial polarization direction.