摘要:

An analysis of the formation of Moiré fringes by the intensity addition of two high-frequency fringe systems shows that the resulting Moiré fringes will retain sinusoidal intensity distribution regardless of whether the contributing fringe systems follow the Airy formula or the cos2law. This, it is shown, is due to the creation in each diffracted order of a ‘double source juxtaposition’. True Airy-type Moiré fringes were realized in holography. The contributing fringe systems were of a multiple-beam Fizeau-Tolansky type. The holographic reconstruction, for each diffracted order of the multiple sources of the interferometer, results in the formation of narrow, sensitive, high-resolution Moiré fringes. These may be applied to real time tests of a micro-object's deformation.

ISSN:0030-3909    

DOI:10.1080/713819714

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The light beam is attenuated inside the recording medium. The recording and reconstruction characteristics of the thick hologram grating recorded in such a medium are described, taking into account of the absorption of the recording medium. The profile of the hologram grating is described and the influence of the absorption upon the diffraction efficiency and the angular sensitivity for both the transmission and reflection holograms is calculated using a coupled wave theory. The calculated results are supported with the experimental data obtained with 649F and dichromated gelatin plates.

ISSN:0030-3909    

DOI:10.1080/713819718

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713819720

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The authors report a study on thermal lensing of an elliptically shaped optical beam in an absorbing dielectric media. It is found in the case of lead glass (withdn/dT, the rate of change of refractive index with temperature, positive) that the beam gets focused at different focal points in different directions, exhibiting the effect of astigmatism. There are several critical points, below the lowest of which there is no self-focusing, but at higher powers one dimension focuses while the other defocuses. Above the higher critical power, both dimensions self-focus, and the dimensionless beam-width parametersf1andf2forxandyfocusing reach different minima corresponding to different self-focusing distances, beyond which both dimensions continue to diverge. In the case of crystal NaCl (wheredn/dTis ne gative), both dimensions of the beam defocus, whatsoever the power of the incident beam.

ISSN:0030-3909    

DOI:10.1080/713819722

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The diffraction of light by an acoustic wave generated by an oppositely phased transducer array is studied. Special attention is paid to the parasitic second-order diffraction which takes place in the usual deflector design at the frequency-band centre, and which results in a decrease in the first-order diffraction efficiency. On the basis of a simplified three-coupled-wave analysis, a modified deflector design is suggested which minimizes the diffraction efficiency dip in the deflector frequency-band centre.

ISSN:0030-3909    

DOI:10.1080/713819715

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The signal-to-noise ratio (SNR) of an optical heterodyne receiver depends on the transmissivity of the beam splitter used. With a proper choice of the transmissivity, some of the loss in the SNR may be alleviated.

ISSN:0030-3909    

DOI:10.1080/713819711

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/716099440

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713819717

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713819712

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/716099438a

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor