摘要:

Among the quantum optical states of a tremolant optical cavity are multimode coherent states. Such states are also possible in open cavities where the cavity stabilization time is greater than the multimode beat time. In open cavity resonator lasers they reduce the power limiting effects of spectral hole burning and therefore tend to grow at the expense of single mode coherent states.

ISSN:0950-0340    

DOI:10.1080/09500349414551771

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Holograms were recorded on photopolymerizable materials with nonlinear behaviour and the diffraction efficiency changes taking place were analysed with light different from that used for the recording. A theoretical model is proposed which explains with good concordance the experimental results, and which allows holography to be used as a spectroscopic technique for monitoring photopolymerizations.

ISSN:0950-0340    

DOI:10.1080/09500349414551781

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A theory of visible light diffraction by a volume grating is given for the case when reflection at slab interfaces cannot be neglected. A method of approximate solution of the second-order coupled-wave equations, applicable over a wide range of the grating vector orientation, is proposed. An appropriate boundary-value problem is discussed and solved in the two-wave approximation. The results are analytical and expressed in matrix notation suitable for both transmission and reflection diffraction gratings. Particular attention is given to the diffraction regime that arises in a slanted grating under the total internal reflection of the diffracted wave (TIRDW). Strong transmission anomalies occurring in the vicinity of the TIRDW threshold are established and analysed.

ISSN:0950-0340    

DOI:10.1080/09500349414551791

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

In this paper we introduce the even binomal state, which interpolates between the even number state and the even coherent state. We consider the effect of this state on the Glauber second order correlation function. Both squeezing phenomena are discussed, i.e., normal squeezing and amplitude squared squeezing. The quasiprobability distribution functions (Wigner function andQfunction) for such a state are also examined.

ISSN:0950-0340    

DOI:10.1080/09500349414551801

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The normal (canonical) form for Mueller matrices in polarization optics is derived: it is shown that a non-singular real 4 × 4 matrixMqualifies to be the bona fide Mueller matrix of some physical system if and only if it has the canonical form M = L′ ΛL, whereLandL′ are elements of the proper orthochronous Lorentz groupL↑+, and where Λ = diag (λ0, λ1, λ2, λ3) with λ0≥ ¦λj¦ > 0. It is further shown that λ1and λ2can be taken to be positive so that the signature of λ3is the same as that of detM. Several experimentally measured Mueller matrices are analysed in the light of the normal form. The case of singular Mueller matrices is briefly discussed as a limiting case.

ISSN:0950-0340    

DOI:10.1080/09500349414551811

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

We propose a hole pattern mask which enhances the image quality produced by the optical projection system used in the lithography of large-scale integration (LSI) manufacturing. The hole pattern mask design is realized by a semi-automatic procedure in such a manner that the particular hole image of the real part of the mutual intensity formed by a special condition can be used as the objective hole pattern mask itself, adding a simple optimization procedure which shifts the amplitude origin of the real part of the mutual intensity. An optimized feature of the transmission profile of the mask is considered to be a translucent square with a phase-shifting frame (a frame phase-shifting mask). Our design method benefits from a simple calculation procedure and low computational costs.

ISSN:0950-0340    

DOI:10.1080/09500349414551821

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The diffusion equation is solved in the low-order harmonic approximation, in order to describe the grating formation process in dry photopolymer materials. We describe how the ratio between diffusion and polymerization rates controls the process of grating formation. Nonlinearity and reciprocity failure are predicted. Experimental results are also shown which are in qualitative agreement with the theory.

ISSN:0950-0340    

DOI:10.1080/09500349414551831

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Photocurrent shot-noise suppression is observed in closed optoelectronic loop below the limit (1 − η) of standard shot-noise level (SNL) imposed by conventional theory of photodetector with quantum efficiency η. Experimental results on photocurrent noise are presented for different values of feedback strength and quantum efficiency η of in-loop photodiode. It is shown that at fixed feedback strength the suppression factor does not depend on η. Minimum noise spectral density is observed below the SNL by a factor 17·8 (− 12·5 dB). Such large suppression cannot be explained in terms of an ordinary sub-Poissonian light state in the loop. We suggest the concept of an anticorrelation light state, where the light in the loop is described as a non-stationary state with Poissonian quantum fluctuations, and superimposed anticorrelated classical fluctuations. While the degree of noise reduction in the photocurrent can be arbitrary large, the degree of anticorrelation between the classical and quantum fluctuations in the light beam remains limited by the quantum efficiency of the feedback photodiode. Calculations based on this concept are in a good agreement with experimental data on super-shot-noise power, obtained for the beam extracted from the loop by a beam splitter.

ISSN:0950-0340    

DOI:10.1080/09500349414551841

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Mathematical models are developed to characterize propagation through a turbid medium at three different wavelengths in the visible and near infrared spectral range. These models are based upon relations between the temporal, angular, and spatial spread of electromagnetic unpolarized radiation, geometrical path length, particle size distribution, and the medium's propagation parameters such as Mie scattering, and absorption coefficients, Mie phase-function, and optical thickness. Calculations of the radiation characteristics were carried out using Monte Carlo simulations. Here, atmospheric particulates are used to model turbid media for optical thickness between 1 and 6, emphasizing optical communication applications, The advantage of this work is the ability to predict simply and in real time important radiation parameters relevant to any optical communication system. Results indicate very high correlation between optical thickness and propagation characteristics. For transmission, comparison is made to Bucher's model. Results are similar except for absorption effects which are not included in Bucher's model. Some important conclusions are derived such as the prediction that it is advantageous to use longer wavelength radiation through the atmosphere. In addition, there is a very dominant back scattering effect, involving up to 50% of transmitted power for optical densities as low as 6. On the other hand, power density of received scattered light is very low for conventional distances relevant to satellite optical communication, and can be neglected. On the basis of simulation results, the received radiation is of unscattered light only for any optical communication application. The dominant mechanism relating to radiation attenuation is scattering rather than absorption.

ISSN:0950-0340    

DOI:10.1080/09500349414551851

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

An expression is derived for the spectral degree of coherence in any pair of points in a field produced by an infinitely large, planar, secondary Lambertian source of uniform intensity. Using this expression, contour diagrams and other diagrams are obtained which show the behaviour of the modulus and of the phase of the degree of spectral coherence throughout an arbitrary three-dimensional region in the half-space into which the source radiates.

ISSN:0950-0340    

DOI:10.1080/09500349414551861

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor