Abstract: A method and apparatus for modulating light, wherein a light source provides light of a certain wavelength to be modulated by a layer of superconducting material which forms part of a specifically configured plate assembly. The superconducting layer is placed in the optical path of the light source. Further the superconducting layer is switched between a partially transparent non-superconducting state and a substantially non-transparent superconducting state by a modulation circuit. The resulting optical pulses transmitted through the superconducting layer are converted from the original wavelength to a lower wavelength by a frequency converting device.

Abstract: A personal fitness monitoring device and a method for assessing the fitness of an individual as the individual exercises includes using a pedometer to determine and output data representing the locomotion of the individual. A heart rate monitor determines and outputs data representing the heart rate of the individual. A determination arrangement calculates the fitness of the individual as the individual exercises using personal data provided by the individual in combination with the data outputs of the pedometer and the heart rate without requiring a predetermined exercise regime. In one embodiment, the pedometer calculates a distance traveled by the individual using personal data provided by the individual. The personal fitness monitoring device may further include a user interface for communicating with the user. The user interface uses a single user controlled selecting mechanism to select a desired one of various user selectable options.