Showing papers on "Photodetection published in 1978"
TL;DR: In this article, a comparison of photodetection with conventional RF detection techniques for infrared wavelengths (λ ~ 10 μm) is outlined, and it is demonstrated that the RF detection technique offers very large potential gain in detection sensitivity and that there is an advantage in using optical heterodyne mixing in both detection methods.
4 citations
TL;DR: In this paper, the quantum electrodynamics of two atoms in free space, separated by many wavelengths and interacting with one another via the coupling of their dipole moments to the electromagnetic field, is studied using the Heisenberg-operator approach.
Abstract: The quantum electrodynamics of two atoms in free space, separated by many wavelengths and interacting with one another via the coupling of their dipole moments to the electromagnetic field, is studied using the Heisenberg-operator approach. The problem is formulated in such a way that one of the atoms, which has two levels, plays the role of a detector; the other atom, whose levels are arbitrary but do not involve cascadelike transitions, plays the role of the source. Several aspects of the interaction are considered, including: a review of photodetection theory, the theory of an alternative detection method that uses an excited-state detector, and a study of quantum beats. These dynamical studies of emission and detection provide new insights into the observation of quantum beats in the transition rate of a detector. We show that ground-state beats are not observed by a detector atom making an upward transition, but that ground-state beats are, in principle, observable if the detector atom makes a downward transition.
4 citations
TL;DR: In this article, a theoretical discussion with experimental comparison of the factors limiting the performance of a surface acoustic wave spectrum analyser plus digital integrator when used with photodetection pulses at the input is presented.
Abstract: The author presents a theoretical discussion with experimental comparison of the factors limiting the performance of a surface acoustic wave spectrum analyser plus digital integrator when used with photodetection pulses at the input. It is shown that photodetection-noise-limited operation can normally be achieved in which case the performance is expected to be similar to that attained with a digital autocorrelator. A discussion of the factors which ultimately limit the performance of such a system is included. Finally, examples of actual optical measurements are given demonstrating that the expected performance can indeed be achieved.
2 citations
TL;DR: In this article, the effects of nonzero detector temperature, where the initial thermal-equilibrium occupation of the atomic levels and the thermalization of the radiation field interfere with the measurement of the photon statistics, were investigated.
Abstract: We present a theoretical study of photodetection with coupling of the photosensitive atoms to a reservoir. We investigate the effects of nonzero detector temperature, where the initial thermal-equilibrium occupation of the atomic levels and the thermalization of the radiation field interfere with the measurement of the photon statistics. We derive formulas exhibiting the temperature dependence of the field dynamics, the relationship between field and atomic moments, and the photocounting probability. We present examples illustrating how the coherence properties of the incoming field are affected by the detection process in the presence of thermal noise.
2 citations
TL;DR: In this paper, the availability of a cw iodine laser and feasibility of highly sensitive photodetection of iodine atoms provide a basis for developing a highly stable frequency standard utilizing an iodine atomic beam.
Abstract: The availability of a cw iodine laser and feasibility of highly sensitive photodetection of iodine atoms provide a basis for developing a highly stable frequency standard utilizing an iodine atomic beam. Possible use of thallium and lead atomic beams for the same purpose is considered.
1 citations