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Query: UMLS:C0002986 (Fabry)
 5,646 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report what is believed to be the first observation of lasing of an optically pumped thin CdS film formed by laser ablation on glass. Laser action is observed at room temperature, and the emission peak is at 501 nm. X-ray diffraction shows that the polycrystalline films are of wurtzite structure and have (002) preferred orientation. Fabry-Perot laser modes are spaced 16 nm apart, indicating a cavity length of 2.9mum . The cavity is formed by consistently self-formed microcavities within the hexagonal lattice.
Opt Lett 1999 Sep 15
PMID:Microcavity lasing of optically excited cadmium sulfide thin films at room temperature. 1807 79

A pulse train with a repetition rate of 115GHz was obtained at 1.55 microm from a continuous-wave modulational-instability erbium-doped fiber laser. This laser has a Fabry-Perot filter whose free spectral range is set at 115GHz, corresponding to the modulational-instability gain peak. This filter enables us to initiate modulational instability easily with a low threshold and produce a stable, continuous-wave pulse train. The stability of the pulse train is greatly improved by suppression of supermode noise with a combination of self-phase modulation and a narrow-band optical filter.
Opt Lett 1997 Sep 15
PMID:Low-threshold 115-GHz continuous-wave modulational-instability erbium-doped fiber laser. 1818 53

We have observed optical bistability caused by absorption-induced thermal expansion of mirrors forming a Fabry-Perot interferometer. From the resulting anomalous transmission line shapes, absorption coefficients of the mirror coatings as low as 0.2parts in 10(6) (ppm) have been successfully measured.
Opt Lett 1997 Sep 15
PMID:Optical bistability induced by mirror absorption: measurement of absorption coefficients at the sub-ppm level. 1818 61

Real-time control by multiwavelength phase-modulated ellipsometry (PME) of the growth of multilayer structures deposited on transparent glass is presented. The structures consist of plasma-deposited SiO(2) and SiN(x) stacks. A model that takes into account incoherent reflection in the substrate is described and tested. A generalized feedback control method that incorporates the incoherent modeling of the transparent substrate is further applied to the growth of a Fabry-Perot and a standard quarter-wave filter. The resulting optical coatings characterized by spectroscopic PME and transmission measurements show a reproducible precision, with less than 1% error between target and measured spectral responses.
Appl Opt 1997 Sep 01
PMID:Real-time control by multiwavelength ellipsometry of plasma-deposited multilayers on glass by use of an incoherent-reflection model. 1825 88

The worldwide endeavor to build long baseline laser interferometers to detect and study gravitational radiation is well under way. In the German-British GEO600 project, it is proposed to pass the sidebands induced on the light by an electro-optic phase modulator through a Fabry-Perot optical cavity used in transmission, called a mode cleaner. This can be achieved when the phase modulation frequency is matched to the first longitudinal-mode frequency of the mode cleaner cavity so that both carrier and sidebands are transmitted. The primary function of the mode cleaner is to reduce the geometry fluctuations associated with the light, and thus any such noise induced by the modulation process is also suppressed. We present the results of an experiment that investigates the feasibility of passing modulation sidebands through an optical cavity and the factors limiting its success. In particular, we show that it is possible to avoid introducing excess noise associated with the transmitted sidebands, provided that certain experimental criteria are satisfied. The research was carried out on a prototype mode cleaner cavity built and tested at Glasgow University but which is similar to the equivalent apparatus planned for GEO600.
Appl Opt 1997 Sep 20
PMID:Response of a Fabry-Perot optical cavity to phase modulation sidebands for use in electro-optic control systems. 1825 48

The band spacing of the fringes of equal chromatic order of a thin Fabry-Perot interferometer is compared when this interferometer contains air, a solid, or a liquid. This comparison enables the dispersion of the group velocity of light in these media to be known accurately to 2.4 parts in one thousand. The Sellmeier dispersion function is used to deduce the refractive indices with the same degree of accuracy. The order-transformation method is used to find the exact order values from the roughly known optical thickness. The exact order values for air and the sample are used to find the refractive index accurately to approximately 3 x 10(-5). A least-squares fitting of the accurate experimental data to the Sellmeier dispersion function enables the coefficients of the latter to be more precisely defined for solids such as glass and mica and for liquids such as glycerin and distilled water. The atomic parameters such as the density of states and the absorption wavelengths in the ultraviolet region of the spectrum for the given samples are deduced from the more precisely found Sellmeier coefficients.
Appl Opt 1997 Sep 20
PMID:Accurate determination of solid and liquid dispersions from spectra channeled with the Fabry-Perot interferometer. 1825 54

Analytic models, based on a convolution of a Fabry-Perot etalon transfer function with a Gaussian spectral source, are developed for the shot-noise-limited measurement precision of Doppler wind lidars based on the edge filter technique by use of either molecular or aerosol atmospheric backscatter. The Rayleigh backscatter formulation yields a map of theoretical sensitivity versus etalon parameters, permitting design optimization and showing that the optimal system will have a Doppler measurement uncertainty no better than approximately 2.4 times that of a perfect, lossless receiver. An extension of the models to include the effect of limited etalon aperture leads to a condition for the minimum aperture required to match light collection optics. It is shown that, depending on the choice of operating point, the etalon aperture finesse must be 4-15 to avoid degradation of measurement precision. A convenient, closed-form expression for the measurement precision is obtained for spectrally narrow backscatter and is shown to be useful for backscatter that is spectrally broad as well. The models are extended to include extrinsic noise, such as solar background or the Rayleigh background on an aerosol Doppler lidar. A comparison of the model predictions with experiment has not yet been possible, but a comparison with detailed instrument modeling by McGill and Spinhirne shows satisfactory agreement. The models derived here will be more conveniently implemented than McGill and Spinhirne's and more readily permit physical insights to the optimization and limitations of the double-edge technique.
Appl Opt 1998 Sep 20
PMID:Modeling of direct detection Doppler wind lidar. I. The edge technique. 1828 55

We describe a micromachined optical fiber current sensor. The sensing element consists of a squared silicon membrane (8 mm long and 20 microm thick) that has a cylindrical permanent magnet (NdFeB alloy, 3-mm diameter, 1.5 mm high) fixed on its central region. This structure allows the permanent magnet to vibrate in the presence of the magnetic field gradient generated by an ac. A linear relation between the electrical current and the magnet displacement was measured with white-light interferometry with an optical fiber low-finesse Fabry-Perot microcavity. A measurement range of 0-70 A and a minimum detectable intensity of 20 mA were obtained when distance D between the membrane and the electrical power line was 5 mm. The output signal directly shows a linear response with distance D.
Appl Opt 1999 Sep 01
PMID:Micromachined optical fiber current sensor. 1832 31

An optical-loss measurement system based on a resonant Fabry-Perot cavity at 1.06 microm in vacuum has been developed for independent monitoring of the cavity total loss and the optical absorption loss. Maintenance of cavity resonance over a one-month period allows the assessment of long-term degradation of the cavity optics in the presence of outgassing materials, with sensitivities of 5 ppm/yr for total cavity loss and 2 ppm/yr for cavity absorption loss. Test results for light-emitting diodes, Kapton-insulated cable assemblies, and Vac-seal epoxy adhesive are given. Scaling of these results to the optical performance requirements of LIGO is discussed.
Appl Opt 1999 Sep 01
PMID:Optical contamination screening of materials with a high-finesse Fabry-Perot cavity resonated continuously at 1.06- microm wavelength in vacuum. 1832 41

The influence of the TiO(2) concentration (<or=10 at. %) on the structural and the optical properties of CaF(2)-rich CaF(2)-TiO(2) composite films fabricated by reactive ion-assisted codeposition are investigated. The composition-dependent properties are found to be similar to those reported for composite films with higher TiO(2) concentrations. The surface roughness of CaF(2) films and their adhesion to a glass substrate are greatly improved by the addition of a small amount of TiO(2). These composite films are quite suitable for IR coatings as a transparent, low-refractive-index material at wavelengths of <10 microm. Two examples, a Fabry-Perot filter and a mid-IR dichroic filter, of applications that use CaF(2)-TiO(2) with 10-at. % TiO(2) and Ge as low- and high-refractive-index coating materials, respectively, are presented.
Appl Opt 1999 Sep 01
PMID:Ion-assisted codeposition of CaF2-rich CaF2-TiO2 composites as infrared-transmitting films. 1832 53


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