Thin-film Optical Waveguide Research Articles

Zigzag ray model of hybrid modes in thin-film optical waveguides with uniaxial anisotropic substrates

We give a model of zigzag rays of hybrid modes propagating in a thin-film optical waveguide on uniaxial anisotropic substrates. The oblique power flow of the hybrid modes, which depends on the polarization, is represented by introducing a transverse shift as well as a longitudinal shift of the rays. The polarization of the zig-zag rays in the film is given. The transverse component of power flow in the film (but not in the top layer or the substrate) is ignored in this model. It is numerically shown that near the degenerate points the oblique direction of the ray propagation obtained by the present zigzag ray model is in agreement with that of the power flow.

Aluminum anodizing technique for fabricating optical thin-film waveguides: a proposal

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text Mitsunobu Miyagi, Yuji Hiratani, Toshimitsu Taniguchi, and Shigeo Nishida, "Aluminum anodizing technique for fabricating optical thin-film waveguides: a proposal," Appl. Opt. 26, 970-971 (1987) Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article

Generalized dispersion properties of a four-layer thin-film waveguide

A general analytic expression is derived, which describes the dispersion properties of a four-layer thin-film optical waveguide. The formula describes the variation of the effective refractive index with respect to any physical parameter with which the refractive index of any layer or the thickness of the guiding layers may vary. Normalized parameters are used, and curves are presented which describe the contributions of the individual layers and waveguide geometry to the total dispersion. Uses of the formula are illustrated for the cases of temperature and wavelength dispersions. Results show that considerable control of the effective index of refraction is possible. Application to the control of chromatic dispersion in a thin-film Luneburg lens is also demonstrated.

Generalized dispersion properties of thin-film waveguides

The dispersion properties of a thin-film optical waveguide for TE and TM modes are expressed in simple and general analytic forms. These formulas describe the variation of the effective refractive index with respect to any physical parameter with which the refractive index of any layer or the thickness of the guiding layer may vary. Universal curves for both TE and TM modes are given, and applications of the formulas are discussed.

Radiative Bragg mirrors: Spectral characteristics versus grating groove profile

The spectral characteristics of radiative Bragg mirrors are theoretically investigated. The mirrors are assumed to be corrugated portions of an optical thin-film waveguide. It was found that the mirror bandwidth can be significantly varied by a slight change of the grating groove profile. The asymmetry of the reflection line is also found to be strongly dependent on the groove profile.

Properties of chalcogenide glasses for optical waveguides

This paper reports on the fundamental background premises of the chalcogenide glasses use in the fiber and thin-film waveguides fabrication. It also presents the data obtained in the investigation of optical, electrical and photoelectric properties of chalcolgenide glass fibers. Certain optical properties of the chalcogenide glass thin-film waveguides have been determined. The possibility of using thin-film optical waveguides, based on chalcogenide glasses in constructing passive and active elements for integrated optics, is demonstrated. Promising applications of the optical waveguides, based on chalcogenide glasses, are described.

New semiconductor materials and structures for electro-optical devices

New semiconductor materials and device structures are essential to the development of new types of electro-optical devices and systems in areas such as integrated optics, optical communications, and optical computing. This paper presents a discussion of basic materials requirements, in terms of both optical properties and materials fabrication technologies, for representative electro-optical devices. In the area of optical communications, interest is shifting towards longer wavelengths, which generates the need for sources and detectors operating in the same region. The current status and future possibilities for such devices, as examplified by fast photodetectors, are discussed in terms of new semiconductor alloy materials and device structures. In the areas of optical computing and integrated optics, the basic essential structure is a low-loss optical thin-film waveguide. The materials aspects of such devices are discussed, and the relevant considerations are illustrated through a description of recent work with GeO2 waveguides.

Tunnel generation and locking stimulated Raman radiation components

Stimulated Raman radiation is considered in a ring optical resonator. It is supposed that the resonator is partly filled with a condensed medium at the full length of the medium close to several tunnel lengths. A Raman-active medium and an optical waveguide are assumed to occupy a part of the condensed medium. The feasibility is shown of tunnel generation and synchronization of a great number of Stokes components of stimulated Raman radiation. Here, femtosecond light pulses are shown to be formed in a spacing adjacent to the Raman-active medium, the pulses being single over the period <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T = 2\pi/\omega_{R}</tex> (ω <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</inf> is the Raman frequency shift). Predicted and considered also are tunnel generation and locking of new light modes in an optical parametric oscillator. The effects are due to a correction for the dispersion of the full effective refractive index of the medium inside the resonator. Numerical calculations of the correction for a glass thin-film optical waveguide, quartz, and the Raman-active media CaCO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> , C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> H <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> , CS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> inside the resonator are represented. Here, five or six Stokes components are shown to be generated and locked for CaCO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> and C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> H <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> , eight Stokes components for CS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> . A similar numerical calculation is represented for the active medium LiNbO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> in the corresponding optical parameteric oscillator. Here, new modes covering a frequency bandwidth of 5000 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> are shown to be feasible. Noted and discussed is also a higher-order correction for the effective refractive index dispersion making it feasible to broaden the frequency bandwidth for tunnel generation and locking.

Raman spectroscopy in polymeric thin film optical waveguides. 1. Polarized measurements and orientational effects in two-dimensional films

Determination de l'orientation d'une couche mince de polymere amorphe ou semicristallin depose sur un substrat de Pyrex formant un guide d'onde optique, a partir des spectres Raman

Observation of coherent Raman scattering in thin-film optical waveguides

We have measured coherent surface Raman scattering in 2-microm-thick films of polystyrene by guiding the incident and scattered light in the film. Peak conversion efficiencies of 0.2% were found, in excellent agreement with theoretical predictions.

Photoinduced grating filters in GeO_2 thin-film waveguides

Narrowband grating filters were fabricated in GeO2 thin-film optical waveguides by optically induced changes in the refractive index. Intense counterpropagating laser beams inside the waveguide resulted in distributed feedback reflectors having a peak efficiency of 40%. The spectral response of the filters was measured by thermal tuning of the center frequency and agreed with the results of a coupled-mode analysis. The filter bandwidths were &lt;0.01 nm.

Use Of Laser Annealing To Achieve Low Loss In Corning 7059 Glass, ZnO, Si3N4, Nb205, and Ta205 Optical Thin-Film Waveguides

We report considerable success in using the technique of laser annealing to reduce scattering in a variety of thin-film optical waveguides deposited onto thermally oxidized silicon substrates. For the materials Si3N4, Nb2O5, and Ta205, values of waveguide loss less than 1 dB/cm were achieved. Values of waveguide loss as low as 0.01 dB/cm have been measured for laser-annealed ZnO waveguides and for Corning 7059 glass waveguides which have been both laser annealed and had surface coatings applied.

Ion implanted grating couplers for optical waveguides

Fabrication of grating couplers by ion implantation for thin-film optical waveguides is reported. Ion implanted grating couplers were fabricated in both Corning 7059 glass waveguides and Ti-in-diffused LiNbO3 waveguides. Experimental coupling efficiencies on the order of a few percent were observed and agree reasonably well with expected theoretical values.

Low-loss GeO_2 optical waveguide fabrication using low deposition rate rf sputtering

Low-loss GeO(2) thin-film optical waveguides have been prepared using rf reactive sputtering with a GeO(2) target, and the propagation properties of the waveguides prepared over a wide range of fabrication conditions have been investigated. We have found that the waveguide attenuation dramatically decreased when a very low deposition rate of rf reactive sputtering in an argon-oxygen atmosphere was used in conjunction with appropriate annealing. In particular, 3800-A thick GeO(2) thin-film optical waveguides have been prepared with propagation losses <0.7 dB/cm for the TE(0) mode at a wavelength of 0.63 microm. The average refractive index of the GeO(2) films was measured to be 1.6059 at lambda = 5461 A by an ellipsometer technique in good agreement with measurement on bulk materials. Propagation losses have also been measured at different wave-lengths, which shows that GeO(2) thin-film optical waveguides could be used over a very wide wavelength range from the visible to the near infrared.

Brillouin scattering in thin film optical waveguides. III. Experiments

A series of experimental results on Brillouin scattering in thin film optical waveguides is discussed for two scattering geometries and for three types of planar waveguides. The results of these experiments are compared with the theory presented in the previous two papers.

Brillouin scattering in thin film optical waveguides. II. Scattering theory

The general theory of Brillouin scattering out of the guided optical modes by the acoustic modes of a thin film optical waveguide is formulated in terms of a total field analysis which includes the effects of both the elastooptic and corrugation scattering mechanisms. The general analytical forms for the field discontinuities at the film boundaries are given and the spectral densities are evaluated for two particular radiative geometries. The results of numerical calculations for the geometries are presented.

Brillouin scattering in thin film optical waveguides. I. Theory of the phonon modes

The phonon modes of a thick plate and a thick plate coated with a thin film are discussed in the light of recent experiments on Brillouin scattering in thin film optical waveguides. Using the reflection coefficients for bulk waves, we have obtained the field structures, the mode normalization for excitation by thermal fluctuations, and the density of states for these modes. Both bulk and surface (Rayleigh, Sezawa, and Love) phonons are discussed.

Propagation characteristics of a multilayered thin-film optical waveguide with a buffer layer

A mode-matching method is applied for precise numerical analysis of the propagation characteristics of a four-layer thin-film optical waveguide with a plano-convex layer, whose accurate description has been difficult so far. In the computation, the effects of the buffer layer on the dispersion relation and the field distribution for a few lower-order modes are investigated.

Reduction Of The Effects Of Scattering By Laser Annealing Of Optical Waveguides And By Use Of Integrated Waveguide Detection

The use of laser annealing with a CO2 laser to improve the quality of both Corning 7059 and phosphosilicate glass (PSG) thin-film optical waveguides will be described. Dark-field photomicrographs taken before and after laser annealing imply that both surface and bulk defects are removed by laser annealing. Waveguide attenuation is typically measured to be on the order of 10 dB/cm before laser annealing, while after laser annealing values significantly lower than 0.1 dB/cm have been measured. We shall discuss the integration of a photodetector array and the optical waveguide structure, and the fact that for such a structure less scattering reaches adjacent array elements than when these two structures are not integrated. The dynamic range of the integrated optical signal process of interest would thus be expected to be greater for the integrated configuration.

Determination of optical constants of vacuum- evaporated II-VI compound thin films with thin film optical waveguides

Optical constants of high index II-VI compound thin films on low index glass waveguides are determined by complex propagation constants via a complex dispersion relation. The results are compared with optical constants of bulk crystals of the II-VI compounds.