scispace - formally typeset
Search or ask a question

Showing papers on "Total internal reflection published in 1985"



Journal ArticleDOI
TL;DR: In this paper, it was shown that reflection of a plane monochromatic wave by the surface of a corrugated waveguide structure may excite a guided mode in one of the diffraction orders and thus alter greatly the reflection and transmission coefficients of the incident wave until total reflection or total transmission are achieved.
Abstract: It is shown that reflection of a plane monochromatic wave by the surface of a corrugated waveguide structure may excite a guided mode in one of the diffraction orders and thus alter greatly the reflection and transmission coefficients of the incident wave until total reflection or total transmission are achieved.

184 citations


Journal ArticleDOI
TL;DR: A linear internal wave model for reflection off a sloping bottom applied to a field of horizontally isotropic waves typical of the deep ocean leads to a strongly perturbed frequency-vertical wavenumber energy spectrum.
Abstract: A linear internal wave model for reflection off a sloping bottom applied to a field of horizontally isotropic waves typical of the deep ocean leads to a strongly perturbed frequency-vertical wavenumber energy spectrum. The spectrum is dominated by a nonintegrable singularity at the internal wave critical frequency characteristic of the environment and bottom slope. An observational requirement that the internal wave spectrum near the bottom relax to the open deep-ocean level and shape within a few hundred meters vertically implies a flux imbalance normal to the boundary. The flux that must be redistributed over the internal wave spectrum, or lost from it, amounts to O(10−2 W m−2), larger than for most other energy transfer mechanisms estimated for internal waves. A small fraction of this flux imbalance applied to mixing can account for a basin-averaged effective vertical diffusivity of 10−4 m2 s−1. Bottom reflection represents not only a likely and powerful sink for internal wave energy, but a me...

179 citations


Journal ArticleDOI
TL;DR: In this article, a consistent set of χ(2) tensor components for a thin layer of rhodamine-6G adsorbed on fused silica is found based on data from reflection and transmission measurements.
Abstract: The theoretical investigation of sum and difference frequency generation in thin surface layers with rotational symmetry leads to formulas which connect the generated light intensities to the surface second order nonlinear susceptibility tensor. A maximum of seven tensor components can be determined in the case of lowest symmetry. Measurements in transmission should be especially useful since they allow easy variation of both polarization and angle of incidence. On the other hand, large signal enhancements are expected for total internal reflection geometries. A consistent set of χ(2) tensor components for a thin layer of rhodamine-6G adsorbed on fused silica is found based on data from reflection and transmission measurements.

170 citations


Patent
26 Dec 1985
TL;DR: In this article, polarized light is directed against an interface in an implant between a transparent material and the blood, with the result that the reflected intensity varies dramatically with index of refraction and with glucose concentration.
Abstract: A blood glucose monitor which is particularly applicable for use as an implant for controlling an insulin pump, or as a portable device for use by a diabetic for home blood glucose monitoring. The glucose monitor measures the glucose level of blood by utilizing a refractometer which measures the index of refraction of blood adjacent to an interface with a transparent surface of the refractometer, by directing light at the interface to measure the index of refraction of the blood by the amount of radiation reflected by the interface, particularly light incident near the critical angle. In a preferred embodiment, polarized light is directed against an interface in an implant between a transparent material and the blood. As the glucose concentration in the blood changes, its index of refraction changes, as does the intensity of light reflected from the interface. The angle of incidence of the light is selected to be slightly less than the critical angle for total internal reflection, with the result that the reflected intensity varies dramatically with index of refraction and with glucose concentration. A differential amplifier compares the intensity of the light reflected from the blood and the intensity of the beam before reflection. The output signal from the differential amplifier indicates only a change in the intensity of the reflected light caused by a change in the glucose concentration from a standard setting.

136 citations


Journal ArticleDOI
David H. Auston1, K. P. Cheung1
TL;DR: In this paper, a new approach to far-infrared spectroscopy is described that uses extremely short farinfrared pulses to measure the dielectric properties of materials, which is equivalent to having a tunable laser in the spectral range from 0.1 to 2 THz.
Abstract: A new approach to far-infrared spectroscopy is described that uses extremely short far-infrared pulses to measure the dielectric properties of materials. Optical rectification of femtosecond optical pulses is used to produce a Cerenkov cone of pulsed far-infrared radiation of approximately one cycle in duration in the terahertz spectral range. The coherent detection of the electric field of these far-infrared pulses by electro-optic sampling provides a capability for measuring precise changes in the shape of the waveform following reflection or transmission from materials. This method, which is equivalent to having a tunable laser in the spectral range from 0.1 to 2 THz, is illustrated by the measurement of the dielectric response of a solid-state plasma in n-type germanium and a GaAs/GaAlAs multi-quantum-well superlattice.

133 citations


Journal ArticleDOI
TL;DR: In this article, the propagation wave number for planar waveguides with multilayer index profiles is analyzed by the transfer matrix of transmitted and reflected beam amplitudes in multilayers.
Abstract: The propagation properties of optical planar waveguides with multilayer index profiles are analyzed by the transfer matrix of transmitted and reflected beam amplitudes in multilayers. The propagation wave number for guided-wave modes is obtained from the condition that certain elements in the transfer matrix must be zero. This numerical technique requires much shorter computer times compared with the usual method of solving the eigenvalue equations, obtained by setting the characteristic determinant to zero. The analysis is also applicable either to waveguides that have losses or to certain cases of uniaxial dielectric anisotropy. All waveguides are assumed to be magnetically isotropic. Some examples of the analysis of graded-index profiles and calculations of the effect of metal claddings and prism perturbations on guided modes are given.

129 citations


Journal ArticleDOI
TL;DR: The spectrum of cobalt chloride on the fiber is similar to a transmission spectrum rather than an attenuated totla reflection (a.t.r.) spectrum because of the refractive index of the film which is slightly greater than that of the fiber.

125 citations


Journal ArticleDOI
TL;DR: In this paper, the authors demonstrate optical-beam phase conjugation by the process of two-beam coupling in photorefractive barium titanate and show that the incident, image-bearing beam causes exponential gain for counter-propagating waves, which are fed by noise and emerge with a power of the order of 10% of the incident beam.
Abstract: We demonstrate optical-beam phase conjugation by the process of two-beam coupling in photorefractive barium titanate The incident, image-bearing beam causes exponential gain for counterpropagating waves, which are fed by noise and emerge with a power of the order of 10% of the incident beam and phase conjugate to it This is expected from the calculated plane-wave gain plus the analogy to the theory of phase conjugation of complex wave fronts by stimulated Brillouin backscattering We conjugate beams at either 515 or 488 nm at between 10- and 50-mW power, and find, as expected, no frequency shift (<1 Hz) in the process

118 citations


Journal ArticleDOI
TL;DR: A new method for chemical analysis of surfaces by total reflection angle X-ray spectroscopy in RHEED experiments (RHEED-TRAXS) has been developed as discussed by the authors.
Abstract: A new method for chemical analysis of surfaces by total-reflection-angle X-ray spectroscopy in RHEED experiments (RHEED-TRAXS) has been developed When the X-ray take-off angle is set to be the critical angle for total reflection of the characteristic X-ray emitted from the deposited atoms on surfaces, the detection efficiency for the deposit becomes drastically higher owing to the refraction effect of the X-ray This enhancement of surface sensitivity is demonstrated with Ag on Si(111) The smallest detectable amount of Ag is about 001 monolayer or less This sensitivity is comparable to or higher than that of AES

97 citations


Patent
12 Jan 1985
TL;DR: In this article, the authors proposed to eliminate the use of an optical system which converts the form of luminous flux to reduce the weight of a reader and at the same time to facilitate positioning of a photodetector.
Abstract: PURPOSE:To eliminate the use of an optical system which converts the form of luminous flux to reduce the weight of a reader and at the same time to facilitate positioning of a photodetector, by obtaining a focusing error signal from the variation of reflection factor at a level close to a critical angle after combining a diffraction grating with a parallel plate. CONSTITUTION:When parallel beams 17 are made incident vertically on the 1st boundary surface 13 of a parallel plate 13, the beams 17 transmit through the 2nd boundary surface 13b of the plate 13 and are made incident on a diffraction grating 15 to be diffracted there. The diffracted beam 18 is made incident again on the surface 13b and travels straight to reach a point P. The constant of the grating 15 is decided so that the incident angle at the point P is equal to the critical angle of total reflection. Therefore the beam 18 is totally reflected at the point P and made incident on a photodetector 11. The beam 18 is totally reflected if the angle theta is larger than the critical angle thetaS; while the beam 18 transmits partially through the surface 13a if the angle theta is smaller. When a disk 7 gets close to an objective lens 6, the light made incident on the grating 15 is turned into the dispersed luminous fluxes. Then the luminous flux has a semicircular form and is made incident only on a photodetector 11b. While the incident light of the grating 15 is focused when the disk 7 goes further away from the lens 6. Then the luminous flux has a semicircular form and is made incident only on a photodetector 11a.

Journal ArticleDOI
TL;DR: A general, accurate, and explicit expression has been derived for the angular shift of a Gaussian beam that is partially reflected by a dielectric interface that holds for arbitrary incidence angles, including the vicinity of the Brewster angle and asymptotically approaches the results obtained by others for incidence away from that angle.
Abstract: A general, accurate, and explicit expression has been derived for the angular shift of a Gaussian beam that is partially reflected by a dielectric interface. This result holds for arbitrary incidence angles, including the vicinity of the Brewster angle, and asymptotically approaches the results obtained by others for incidence away from that angle. A series of reflected beam profiles is shown to clarify the angular-shift phenomenon and to illustrate the beam-distortion effect that occurs at, or near, Brewster incidence.

Journal ArticleDOI
TL;DR: Degenerate nonlinear light scattering in LiTaO(3) caused by parametric forward four-wave mixing of waves with orthogonal polarization is reported.
Abstract: Degenerate nonlinear light scattering in LiTaO3 caused by parametric forward four-wave mixing of waves with orthogonal polarization is reported. Scattered light is located on a cone whose apex angle is defined by the phase-matching condition. The photorefractive-type nonlinearity involved in this process is caused by the excitation of spatially oscillating photovoltaic currents directed normal to the optical axis and the subsequent formation of a volume space-charge field modulating the refractive index.

Patent
09 Sep 1985
TL;DR: In this article, an optical wave guide is used to measure the total internal reflection of excitation radiation at the interface between the wave guide and a surrounding liquid phase of lower index of refraction.
Abstract: An optical wave guide particularly useful in assay apparatus employing total internal reflection of excitation radiation at the interface between the wave guide and a surrounding liquid phase of lower index of refraction. The wave guide in the form of a solid, light-transmissive, elongated rod or fiber made typically of glass, crystal or plastic and having preferably a circular cross-section, is tapered gradually from an entrance face of relatively large diameter to a substantially smaller diameter at some position longitudinally displaced from the entrance face. In one form, the wave guide is formed with a tapering conical input portion coupled to a second portion having a cylindrical configuration and a diameter matched to the smaller diameter of the tapered portion.

Patent
09 Sep 1985
TL;DR: In this article, an assay method and apparatus employing total internal reflection of excitation radiation at an activated region on the surface of an optically conductive rod or fiber surrounded by a liquid phase of lower index of refraction, so as to excite into fluorescence fluorophores in the liquid present in a thin layer around the rod surface.
Abstract: An assay method and apparatus employing total internal reflection of excitation radiation at an activated region on the surface of an optically conductive rod or fiber surrounded by a liquid phase of lower index of refraction, so as to excite into fluorescence fluorophores in the liquid present in a thin layer around the rod surface. The induced fluorescence is then gathered and measured. Excitation occurs while flowing a sample of the liquid phase through an enclosure of fixed dimensions bounded in part by the activated region.

Journal ArticleDOI
TL;DR: In this paper, the problem of reflection of a Gaussian beam from a parallel-sided dielectric slab is studied from the angular-spectrum point of view, and it is shown that the path of the peak of the reflected profile undergoes three types of effects with reference to its expected geometrical path: a lateral displacement independent of the propagation distance, a focal shift, and an angular shift that results in a lateral shift proportional to the total propagation distance between the beam waist and the point of observation.
Abstract: The problem of reflection of a Gaussian beam from a parallel-sided dielectric slab is studied from the angular-spectrum point of view. It is shown that the path of the peak of the reflected profile undergoes three types of effects with reference to its expected geometrical path: a lateral displacement independent of the propagation distance, a focal shift, and an angular shift that results in a lateral shift proportional to the total propagation distance between the beam waist and the point of observation and independent of the location in between, where reflection takes place. These effects are illustrated by computer simulating some typical cases. The generality of the analysis and its applicability to many different situations are noted. The results of several authors on related problems are shown to be special cases of the general results. The relevance of the analysis and the results to an interesting series of recent experiments in the microwave region is noted.

Journal ArticleDOI
TL;DR: In this paper, the density variation across the liquid-vapour interface was studied, i.e. from the bulk density of the liquid to the essentially zero density of vapour phase.
Abstract: In this short review we are concerned with the density variation across the liquid-vapour interface, i.e. from the bulk density of the liquid to the essentially zero density of the vapour phase. This density variation can in principle be determined from the deviation of the reflectivity from Fresnel's law for incidence angles larger than the critical angle for total reflection. However, in this range the reflectivity may typically have dropped by 7 or 8 order of magnitude from its value below the critical angle, and therefore the availability of intense synchrotron radiation sources have made such measurements practically feasible.

Journal ArticleDOI
TL;DR: In this article, the Kramers-Kronig (KK) transformation is applied to s −polarized light at nonnormal incidence with a transparent incident medium of arbitrary, constant refractive index.
Abstract: The Kramers–Kronig (KK) transformation has been widely used for the determination of the spectra of the refractive and absorption indices from the normal‐incidence reflectivity spectrum of solids. This paper considers the extension of this technique to s‐polarized light at nonnormal incidence with a transparent incident medium of arbitrary, constant refractive index. While the KK transformation is known to be inapplicable under certain circumstances, we show that in all cases satisfactory corrections can be applied, and readily applied in most cases. As an example, for the experimentally important case of attenuated total internal reflection from an organic liquid in the infrared, only one additional piece of information is required, namely, the refractive index at a frequency where the absorption is low. The procedures are demonstrated using model systems consisting of sets of damped harmonic oscillators. All the KK transformations were done using the FT software of a commercial Fourier transform infrared spectrometer in order to demonstrate the considerable potential of this approach to the routine determination of optical constants.

Patent
23 May 1985
TL;DR: In this paper, an in situ probe device is inserted into the system over which individual bubbles flow, and a plurality of independent probes are spatially arranged to detect one or more of the bubble physical characteristics.
Abstract: Method and apparatus are disclosed for determining one or more physical characteristics of individual bubbles in a gas-liquid system and a gas-liquid-solid system at high temperatures and pressures. An in situ probe device is inserted into the system over which individual bubbles flow. The probe device has a plurality of independent probes. Each has a rounded fibre optic end portion projecting into the system. A source of incident light is directed onto each of the probes. The rounded end portion of each probe is formed with a radius of curvature sufficiently large whereby the angle of incidence of the source light at the rounded portion is greater than the angle of total reflection for the fibre optic when in contact with the gas. The angle of incidence is less than the angle of total reflection for the fibre optic when in contact with the liquid. The plurality of probes are spatially arranged to detect one or more of the bubble physical characteristics as a bubble flows over the probe device. The change in light intensity of reflected light emerging from the probe is measured. The change in light intensities of each of the probes over time is evaluated to determine the one or more bubble characteristics. Each probe is formed of sufficiently thin fibre optic and spaced from the other probes of the device to enable detection of the bubble characteristics for individual bubbles flowing over the probe device. This probe system enables the monitoring of physical characteristics of bubbles in two and three phase systems in an efficient, reliable, economical manner. The system also provides for a measure of solid, gas and liquid hold-ups in a three-phase system.

Journal ArticleDOI
TL;DR: The use of surface-impedance and surface-admittance concepts for analyzing reflection and refraction at an isotropic dielectric interface (first developed about 1938) is extended to include an interface between uniaxial birefringent dielectrics as discussed by the authors.
Abstract: The use of surface-impedance and surface-admittance concepts for analyzing reflection and refraction at an isotropic dielectric interface (first developed about 1938) is extended to include an interface between uniaxial birefringent dielectrics. Total internal reflection and the polarizing (Brewster) angle at an anisotropic interface are shown to be naturally explainable in terms of surface impedance (for TM polarization) and surface admittance (for TE polarization). The allowable modes in an integrated optical uniaxial asymmetric dielectric slab waveguide are also shown to be directly obtainable using the surface impedance/admittance approach. Numerical examples are presented.

Journal ArticleDOI
TL;DR: The measured optical second-harmonic generation (SHG) in the total-internal-reflection regime from opaque silver and aluminum films is measured and it is concluded that for incident 1.06-\ensuremath{\mu}m radiation the SHG from silver and Aluminum films is well described by Sipe's hydrodynamic model.
Abstract: We have measured optical second-harmonic generation (SHG) in the total-internal-reflection regime from opaque silver and aluminum films. A recent hydrodynamic theory of SHG from metal surfaces by Sipe shows that at large angles of incidence the SHG in total internal reflection will be sensitive to the normal component of the harmonic surface current. We find that the phenomenological parameter a which estimates the size of this normal component has a value of 0.9 for silver and 1.5 for aluminum. By calibrating the reflected SHG from the opaque metal films to the transmitted SHG from quartz we determine that the theoretical and experimental conversion factors for reflected SHG agree to within 20% for silver and 40% for aluminum. For thin metal films we observe new interference structure in the wings of the surface-plasmon resonance, which also is in good agreement with the theory. We conclude that for incident 1.06-\ensuremath{\mu}m radiation the SHG from silver and aluminum films is well described by Sipe's hydrodynamic model.

Journal ArticleDOI
TL;DR: In this paper, the authors observed several of these shear-coupled P waves on seismograms of deep earthquakes recorded at broadband seismic stations (RSTN) in North America.
Abstract: Teleseismic SV waves couple to P waves in the lithosphere in several ways. P waves converted from discontinuities in the lithosphere precede the main SV arrival as small amplitude Sp precursors. Large amplitude P waves follow the main SV arrival after conversion by reflection at the free surface, and post-critical reflection from a discontinuity in the lithosphere. SPdiff denotes a converted P wave diffracted along the underside of the crust when a teleseismic SV wave strikes it from below near the critical angle of incidence. We observed several of these shear-coupled P waves on seismograms of deep earthquakes recorded at broadband seismic stations (RSTN) in North America. For these paths, large amplitudes relative to SV characterize the lithospheric multiple near 50°, with amplitudes decreasing rapidly beyond 60°. Calculation of synthetic seismograms indicate that a post-critical reflection from a discontinuity at 70-80 km depth where compressional velocity increases abruptly to about 8.5 km/s produce the largest amplitude P arrival. The observations of these shear-coupled P waves presents a previously untapped source of information about the fine structure of the upper mantle.

Journal ArticleDOI
TL;DR: In this paper, a new structure of the PLZT thin film optical TIR (Total Internal Reflection) switches with strip loaded type waveguides was proposed, which achieved 2 GHz intensity modulation of LD light (0.83 µm) and 1 km optical fiber transmission.
Abstract: We propose a new structure of the PLZT thin film optical TIR (Total Internal Reflection) switches with strip loaded type waveguides. Using these switches, we have achieved 2 GHz intensity modulation of LD light (0.83 µm) and 1 km optical fiber transmission. Both lumped constant electrode and traveling wave electrode were examined up to 26.5 GHz. From the calculation of velocity mismatch between the modulating wave and the light wave, it is estimated that the modulation bandwidth of these switches will be more than 100 GHz.

Journal ArticleDOI
TL;DR: The reflection and refraction of light of wavelength lambda at an angle of incidence Phi by the interface between two dielectric media of refractive indices N(0) and N(2) can be made completely independent of polarization by introducing a thin layer ofRefractive index N(1) = (N(0)-N(2))(1/2) and thickness d = (lambda/4) (N-1)(2) - N-0)(2).
Abstract: The reflection and refraction of light of wavelength λ at an angle of incidence ϕ by the interface between two dielectric media of refractive indices N0 and N2 can be made completely independent of polarization by introducing a thin layer of refractive index N1 = (N0N2)1/2 and thickness d = (λ/4)(N12 − N02 sin2ϕ)−1/2. This is the basis of an ideal beam splitter, whose general characteristics are presented here. A particularly simple result is that the device reflectance has an upper limit of tan4(ϕ/2), so that a 50–50% beam splitter must operate at ϕ > 80.121°. Lower reflectances, attainable at lower angles, are suited for applications such as optical feedback and monitoring the output power and state of polarization of high-power lasers.

Patent
29 Nov 1985
TL;DR: In this article, a method and apparatus classifies and grades glossiness based on the visible feeling by the light reflection intensity distribution of a surface of a body, wherein specular reflection intensities and total reflection intensity are detected for two known light fluxes projected at predetermined incident angles.
Abstract: A method and apparatus classifies and grades glossiness based on the visible feeling by the light reflection intensity distribution of a surface of a body, wherein specular reflection intensities and total reflection intensities are detected for two known light fluxes projected at predetermined incident angles. The specular reflection intensities and the total reflection intensities are processed, to thereby determine the glossiness of the work to be measured.

Journal ArticleDOI
TL;DR: In this paper, the attenuation characteristics of hollow alumina waveguides have been measured over the 9-11 µm waveband and it has been shown that the change in the guiding nature of the waveguide changes from being "leaky" at shorter wavelengths to exhibiting attenuated total internal reflection at longer wavelengths.
Abstract: Significant variations in the attenuation characteristics of hollow alumina waveguides (suitable for use in the manufacture of CO 2 waveguide lasers) have been measured over the 9-11 \mu m waveband Existing waveguide transmission theory has been successfully used to explain the qualitative nature of the observed experimental results by taking into account the effects of dispersion due to active lattice absorption bands in alumina The suprising conclusion of the work is that the major variations in attenuation are a result of a complete change in the guiding nature of the waveguide at \sim 10 \mu m At this point, the nature of the waveguide changes from being "leaky" at shorter wavelengths to exhibiting attenuated total internal reflection at longer wavelengths This results in there being a distinct difference in attenuation characteristics for the two main laser emission bands centered at 96 and 106 μm, respectively

Journal ArticleDOI
TL;DR: In this paper, two-dimensional dielectric waveguide corners with air reflector or metal reflector have been investigated by means of the method of plane-wave expansion, which has the advantage of being compact for optical integrated circuit applications.

Patent
29 Apr 1985
TL;DR: In this article, the authors used the principle of total internal reflection to enhance the apparent brightness of the liquid crystal material in a support medium illuminated from the viewing side or direction of the display.
Abstract: In the present invention encapsulated liquid crystal material in a support medium illuminated from the viewing side or direction will appear bright or white relative to background when in distorted alignment, e.g. in the absence of an electric field. Incident light impinging on the liquid crystal material is isotropically scattered thereby into the support medium, and using the principle of total internal reflection a relatively large part of the isotropically scattered light is reflected back to illuminate the distorted liquid crystal material tending to brighten the same so that light it scatters back to the viewing direction out of the support medium causes the liquid crystal material to appear relatively light or bright as compared to the background where there is no liquid crystal material or where the liquid crystal material is in parallel alignment in field-on condition, i.e. aligned with respect to an electric field, and, thus, substantially transmissive. Original incident light where there is no liquid crystal material, that light which is isotropically scattered toward the back or non-viewing side of the display and within a certain cone or solid angle, and that light passing through aligned (field-on) liquid crystal material will tend not to be totally internally reflected; such light will pass through the support medium and may be absorbed by a remote black or colored material. Moreover, principles of optical interference may be employed further to enhance the apparent brightness of the liquid crystal material.

Journal ArticleDOI
TL;DR: In this paper, a new approximate method based on the Green function technique is proposed for estimation of reflection and transmission coefficients, which is valid if a body wave field arised at the boundary is approximately orthogonal to the fields of reflected and transmitted normal modes.

Journal ArticleDOI
TL;DR: In this paper, the same authors considered a general case where the direction of the propagating waves and the orientation of the dielectric tensor make an arbitrary angle with respect to the rotation axis.
Abstract: An optical model is considered describing a wide class of optically anisotropic media such as chiral smectic liquid crystals and, in the limiting cases, cholesteric liquid crystals and anisotropic homogeneous media. It describes a structure having a periodicity along a given axis generated by a uniform rotation of the dielectric tensor. Maxwell's equations for this model, studied so far only in particular cases, are here solved for the general case where the direction of the propagating waves and the orientation of the dielectric tensor make an arbitrary angle with respect to the rotation axis. The resolving procedure involves the evaluation of the eigenmodes of the electromagnetic wave, i.e. the Bloch waves intrinsic to the specific periodic structure, which reduce to the ordinary and extraordinary waves in the limiting case of anisotropic homogeneous structures. The dispersion relation for the eigenmodes is deduced, allowing the study of the optical properties of this structure on a general basis. The Bragg reflection bands are found to be constitued alternatively by singlets and triplets. In general the even order bands are triplets whose lateral peaks correspond to the Bragg instabilities of each eigenmode, while the central peak is common to both eigenmodes and gives total reflection with a mode exchange. The odd order bands are singlets whose characteristics are very similar to the central peak of the triplets. The polarization properties of the eigenmodes are studied in the particular case of locally uniaxial media, where the Bloch waves show an abrupt polarization change for a particular value of the angle between the optical axis and the rotation axis Etude d'un modele optique pour decrire des cristaux liquides smectiques chiraux et, a la limite, des cristaux liquides cholesteriques et des milieux homogenes anisotropes/structures presentant une periodicite le long d'un axe donne, produite par une rotation uniforme du Tenseur dielectrique). Resolution des equations de Maxwell dans le cas general ou la propagation des ondes et l'orientation de l'axe de rotation du tenseur dielectrique forment un angle arbitraire: calcul des ondes de Bloch propres a la structure periodique, qui se reduisent aux ondes ordinaires et extraordinaires pour une structure homogene anisotrope. Deduction des proprietes optiques (bandes de reflexion de Bragg)