Abstract: The present invention additionally comprises a method and apparatus for generating and mixing signals for frequency-domain lifetime and spectral fluorometry. The present invention comprises a plurality of signal generators that generate a plurality of signals where the signal generators modulate the amplitude and/or the frequency of the signals. The present invention uses one of these signals to drive an excitation signal that the present invention then directs and transmits at a target mixture, which absorbs the energy from the excitation signal. The property of fluorescence causes the target mixture to emit an emitted signal that the present invention detects with a signal detector. The present invention uses a plurality of mixers to produce a processor reference signal and a data signal. The present invention then uses a processor to compare the processor reference signal with the data signal by analyzing the differences in the phase and the differences in the amplitude between the two signals.

Abstract: Apparatus and method for measuring the relative distance between different areas on a remote surface or displacements of a selected area of a remote surface with respect to a measuring apparatus are provided. A laser beam is modulated at an RF frequency and focused on a selected area. The selected area is scanned by movement of a mirror and at each selected area the phase difference is measured. Digital data processing of signals derived from the source and return beams is used to provide high precision. For detecting or measuring vibration or displacement, an analog signal is obtained from a low-pass filter.