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Greenwood frequency measurements
Journal of the Optical Society of America A, 1990Recently published data by Colavita et al. [ Appl. Opt.26, 4106 ( 1987)] provide a basis for developing an estimate of the Greenwood frequency for the Mt. Wilson Observatory area. We find that the Greenwood frequency is of the order of 20–40 Hz.
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Optical frequency measurements
Proceedings of the IEEE, 1986This paper is a review of the history of the measurement of coherent optical frequencies. Since coherent optical frequency implies a laser device, this is therefore a review of laser frequency measurement. The development of frequency measurement from the Cs frequency standard to the visible is traced.
D.A. Jennings +2 more
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Frequency Measurement Techniques
IEEE Transactions on Instrumentation and Measurement, 1968This paper considers the problem of digital frequency measurement of band-limited sampled data signals. The signal is assumed to be a fixed sine wave in noise over the measurement interval. The advent of low-cost A/D converters and the drastic price reductions predicted for IC's in the near future make techniques of this type appear practical for ...
Richard Van Blerkom +2 more
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Instantaneous frequency measurement
Medical Electronics & Biological Engineering, 1963A method is outlined for obtaining an indication of instantaneous frequency by a computation of the reciprocal of the time for one period. This is accomplished by the discharge of a condenser through an element having current proportional to the square of the voltage. The square law element consists of a biased diode network.
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Proceedings of the IRE, 1949
This paper indicates the theory involved in making measurements of gain, frequency response, distortion, and noise at audio frequencies, with particular emphasis on such measurements made on high-gain systems. There are also discussed techniques of measurement and factors affecting the accuracy of results.
W.L. Black, H.H. Scott
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This paper indicates the theory involved in making measurements of gain, frequency response, distortion, and noise at audio frequencies, with particular emphasis on such measurements made on high-gain systems. There are also discussed techniques of measurement and factors affecting the accuracy of results.
W.L. Black, H.H. Scott
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2006
The new alliance between the time and frequency domains in laser spectroscopy has made it possible to develop ultrafast counting schemes that can keep track of single optical oscillations. With this achievement, counting optical oscillations of more than 1015 cycles in one second has become a simple task. High-resolution spectroscopy for basic research
Udem, T. +5 more
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The new alliance between the time and frequency domains in laser spectroscopy has made it possible to develop ultrafast counting schemes that can keep track of single optical oscillations. With this achievement, counting optical oscillations of more than 1015 cycles in one second has become a simple task. High-resolution spectroscopy for basic research
Udem, T. +5 more
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2010
In the frequency-domain measurements of luminescence, the excitation intensity is modulated sinusoidally and the emission detected using a phase-sensitive amplifier. The present availability of conveniently modulatable light sources, such as light-emitting diodes and diode lasers, and relatively inexpensive lock-in amplifiers makes this technique well ...
Jouko Kankare, Iko Hyppänen
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In the frequency-domain measurements of luminescence, the excitation intensity is modulated sinusoidally and the emission detected using a phase-sensitive amplifier. The present availability of conveniently modulatable light sources, such as light-emitting diodes and diode lasers, and relatively inexpensive lock-in amplifiers makes this technique well ...
Jouko Kankare, Iko Hyppänen
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Proceedings of the IRE, 1929
Absolute measurement of frequency.-Various methods of absolute measurement of frequency are first described. Particular attention is devoted to the stroboscopic method and the phonic motor method for audio frequencies. A modified method of harmonic comparison is also presented.
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Absolute measurement of frequency.-Various methods of absolute measurement of frequency are first described. Particular attention is devoted to the stroboscopic method and the phonic motor method for audio frequencies. A modified method of harmonic comparison is also presented.
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