Quantum Optics and Electronics

Contains reports on two research projects.Joint Services Electronics Program (Contract DAAG29-78-C-0020)National Science Foundation (Grant ENG79-11380)U.S. Navy - Office of Naval Research (Contract N00014-79-C-0694)National Science Foundation (Grant ENG79-08031

Single Atom and Two Atom Ramsey Interferometry with Quantized Fields

Implications of field quantization on Ramsey interferometry are discussed and general conditions for the occurrence of interference are obtained. Interferences do not occur if the fields in two Ramsey zones have precise number of photons. However in this case we show how two atom (like two photon) interferometry can be used to discern a variety of interference effects as the two independent Ramsey zones get entangled by the passage of first atom. Generation of various entangled states like |0,2>+|2,0> are discussed and in far off resonance case generation of entangled state of two coherent states is discussed.Comment: 20 pages, 5 figures, revised version. submitted to Phys. Rev.

Effect of random-telegraph laser phase on two-photon absorption

© 1995 The American Physical SocietyMeasurements of two-photon absorption spectra have been made for the case where the exciting laser has a random-telegraph phase. The resulting spectral shapes are compared to theoretical predictions and to previous data taken with a phase-diffusing laser field [Elliott et al., Phys. Rev. A 32, 887 (1985)]. A striking dependence of the absorption spectrum on the second-order coherence of the field was observed. Using the theory for the propagation of second-order spatial coherence, we draw an analogy between diffraction and two-photon absorption which we use to interpret the two-photon absorption spectra.G. N. Sinclair, X. Bao, D. S. Elliott, and M. W. Hamilto

Pyogenic granuloma as a presenting sign of hydroxyapatite orbital implant exposure: A clinicopathologic study

PURPOSE: We report 5 unusual cases of exposed hydroxyapatite orbital implants that presented as pyogenic granulomas. We propose pathogenesis and histopathologic correlations. METHODS: A clinicopathologic study of 5 patients with hydroxyapatite implants who presented with pyogenic granuloma. RESULTS: Pyogenic granulomas were detected 1.5 to 30 months after implantation in 5 patients. The lesions were multiple but were not related to the wound margin at the exposed area and were not covered by the surface epithelium in most instances. Exposure defects were detected in all patients at the time of lesion excision. The mean exposure size in the greatest dimension was 16 mm (range, 9-20 mm). Three patients were treated successfully with simple excision of the granulomas, burring down of the anterior surface of the implants, and direct repair of the exposure defects. Explantation of the implant was performed in 2 cases. Histopathologic examination revealed chronic inflammation and microabscess formation in the explanted implants. CONCLUSIONS: Five patients with pyogenic granulomas were found to have hydroxyapatite exposure. Pyogenic granuloma should not be considered a benign lesion on a hydroxyapatite orbital implant, especially in recurrent cases. Ophthalmologists must be aware of the possibility of conjunctival dehiscence with hydroxyapatite-implant exposure beneath the lesion. ©2006The American Society of Opthalmic Plastic and Reconstructive Surgery, Inc