Laser hair removal or laser epilation technology is commonly used to remove hair from a persons skin or even to prevent growth of new hairs. Due to the necessity of high power light sources laser hair removal has been restricted to use in dedicated beauty salons and clinics over a long time. Accordingly it is an object of this invention to provide a light emitting device enabling emission of laser radiation from a housing only under conditions reducing hazard for a consumers eyes. Thus according to a first aspect of the invention there is provided a light emitting device with at least one radiation source for electromagnetic radiation providing at least one operating beam during operation of the device, a housing being intransparent for the operating beam having an output opening, wherein the radiation source providing the operating beam is located in the housing, and wherein the radiation source providing the operating beam and the output opening are arranged such that during operation of the device the operating beam may exit the housing through the output opening, at least one radiation source for electromagnetic radiation providing at least one sensing beam during operation of the device, at least one detector for detecting the sensing beam, at least one sensing window having a contact boundary surface, wherein the detector is arranged such that during operation of the device the sensing beam on a path from the radiation source providing the sensing beam to the detector is at least once reflected at the contact boundary surface of the sensing window by total internal reflection once the contact boundary surface of the sensing window is in contact with air, and a controller communicating with the radiation source providing the operating beam and with a detector and being operable to influence operation of the radiation source providing the operating beam responsive to the sensing beam detected at the detector.
