Application of holographic optical elements to magneto-optic read/write heads

Objectives of this research are to determine the theoretical and practical performance limits of holographic optical elements (HOE's) formed in different recording materials, and to evaluate the application of these components to magneto-optic read/write heads

Roadmap on holography

From its inception holography has proven an extremely productive and attractive area of research. While specific technical applications give rise to 'hot topics', and three-dimensional (3D) visualisation comes in and out of fashion, the core principals involved continue to lead to exciting innovations in a wide range of areas. We humbly submit that it is impossible, in any journal document of this type, to fully reflect current and potential activity; however, our valiant contributors have produced a series of documents that go no small way to neatly capture progress across a wide range of core activities. As editors we have attempted to spread our net wide in order to illustrate the breadth of international activity. In relation to this we believe we have been at least partially successful.This work was supported by Ministerio de Economía, Industria y Competitividad (Spain) under projects FIS2017-82919-R (MINECO/AEI/FEDER, UE) and FIS2015-66570-P (MINECO/FEDER), and by Generalitat Valenciana (Spain) under project PROMETEO II/2015/015

Roadmap on holography

From its inception holography has proven an extremely productive and attractive area of research. While specific technical applications give rise to 'hot topics', and three-dimensional (3D) visualisation comes in and out of fashion, the core principals involved continue to lead to exciting innovations in a wide range of areas. We humbly submit that it is impossible, in any journal document of this type, to fully reflect current and potential activity; however, our valiant contributors have produced a series of documents that go no small way to neatly capture progress across a wide range of core activities. As editors we have attempted to spread our net wide in order to illustrate the breadth of international activity. In relation to this we believe we have been at least partially successful

''Aged'' (dense) circulating red cells contain normal concentrations of ATP

A newly-developed technique for determination of the ATP content of individual red cells to the densest, and hence presumably the oldest, cells from normal human blood was applied. It was found that these cells contain normal concentrations of ATP, although the net content of ATP is decreased. The essence of the technique is suspension of red cells in autologous plasma containing luciferin and luciferase, lysis of the cells with a pulse from a laser, and counting of the photoemissions resulting from reaction of the released ATP with the luciferase. These data appear to disprove the otherwise plausible hypothesis of Lichtman that red cells decline exponentially in ATP content as they age, by one of the suggested tests of this hypothesis. The data suggest an alternative hypothesis: red cells maintain an approximately constant concentration of ATP as they age, and red cell destruction is caused by factors other than cellular ATP

Measurement of adenosine triphosphate (ATP) content in single red blood cells using the firefly bioluminescent reaction

A unique optical instrument is described which uses the firefly bioluminscent reaction to measure adenosine triphosphate (ATP) levels in single red blood cells. The method allows chemical content level to be associated with individual cell features. The optical instrument consists of a phase contrast microscope to view cells, a pulsed argon-ion laser to rupture the cell membrane, and a photon counting system to measure the bioluminescent yield. The technique has been calibrated against a standard ATP measurement using bulk analysis methods. The ATP loss mechanism for blood cells in a controlled depletion experiment was also investigated

Diffraction efficiency and signal-to-noise ratio of multiplexed volume phase holograms recorded in a photographic emulsion

The problems related to noise that arise during recording and reconstruction of holograms used in optical data storage or in massive optical interconnection systems are quite similar and can be analyzed in order to improve the quality of the images that these optical systems provide. In this paper, we will analyze noise in cases in which several coherent object waves are simultaneously stored in a phase recording material in a way that allows us to obtain information about the relationship that exists between the recording material and the number of waves that are being stored. The material used in this study is Agfa Gevaert 8E75 HD holographic film processed with a rehalogenating—type bleach bath without a fixation step. Additionally, we show experimentally that it is possible to holographically store more than 400 waves at the same time (in a coherent fashion) using the same storage geometry, with a signal-to-noise ratio larger than 20 and an average diffraction efficiency of 15%.Part of this work was supported by the Direcció General d'Ensenyaments Universitaris i Investigació of the Generalitat Valenciana, Spain (Project GV-1165/93) and the Comisión Interministerial de Ciencia y Tecnología, Spain (Project MAT93-0369)

Noise gratings with single-beam exposures in silver-halide emulsions: the influence of the bleach bath

Noise gratings recorded with single-beam exposures in bleached silver halide emulsions are analysed as a function of chemical processing. Two types of bleach baths were used in these experiments (one reversal and the other rehalogenating) and the characteristics of these gratings were determined by measuring the transmittance through the processed hologram as a function of the replay angle. The results obtained show that the study of these noise gratings provides information about the bleaching action during the processing

The importance of acquired diffuse bronchomalacia in heart-lung transplant recipients with obliterative bronchiolitis

The results of heart-lung transplantation are improving with increasing experience in postoperative management, but obliterative bronchiolitis may still develop late postoperatively. We have performed 19 heart-lung transplants, with 1-month, 1-year, and 2-year actuarial survival rates of 95% +/- 5%, 84% +/- 8%, and 69% +/- 16%, respectively. Three early recipients died of bronchiolitis, and four patients who were operated on more than 2 years ago are currently being followed up with bronchiolitis. Since August 1988, 13 surviving recipients have undergone serial postoperative bronchoscopies and transbronchial biopsies with topical analgesia. Diffuse bronchomalacia, involving the main bronchi down to the fifth-order bronchi bilaterally, has developed in four patients with bronchiolitis 9 +/- 2 months after the diagnosis of bronchiolitis was confirmed. Pulmonary function tests have revealed a lower ratio of forced expiratory volume in 1 second to forced vital capacity, lower specific airway conductance, and higher airway resistance in heart-lung recipients with bronchomalacia than in patients with bronchiolitis alone. We conclude that diffuse bronchomalacia occurs frequently in heart-lung transplant recipients who have obliterative bronchiolitis. Bronchomalacia worsens the functional airflow obstruction caused by bronchiolitis and may play an important role clinically in the declining respiratory status of heart-lung transplant recipients