Achromatization of optical waveguide components

An investigation aimed at reducing chromatic variations in the performance of optical waveguide devices is described. Methods to achromatize the characteristics of integrated optics lenses, input/output couplers, and beam-splitters are presented with the goal of eliminating, or minimizing, any performance variations over a wavelength interval at least on the order of the operating range of presently available laser diode sources. It is shown that an achromatic waveguide lens can be made using a mode-index/diffractive doublet. With this approach, it is possible to cancel the longitudinal chromatic aberrations of the refractive lens with an appropriate diffractive component. Achromatic input/output couplers are described which use an external diffraction grating to correct for the angular dispersion of either prism or grating couplers. It is shown that double grating couplers can be used to obtain an achromatic wavelength range on the order of ten nanometers, and that hybrid prism/grating couplers can yield an achromatic range of several hundred nanometers. It is also shown that the angular chromatic dispersion of waveguide grating beam-splitters can be corrected using a second grating that is appropriately specified. This permits a guided optical beam to be split into two or more separate beams whose directions are independent of wavelength. These achromatic waveguide components can be combined in various configurations to reduce the wavelength sensitivity of devices such as optical disk pickup heads.

[1]  T.M. Turpin,et al.  Spectrum analysis using optical processing , 1981, Proceedings of the IEEE.

[2]  M. C. Hamilton,et al.  An Integrated Optical RF Spectrum Analyzer , 1977 .

[3]  R. J. Martin,et al.  Geometrical optics in thin film light guides. , 1971, Applied optics.

[4]  J. Boyd,et al.  Comparison of optical-waveguide lens technologies , 1977, IEEE Journal of Quantum Electronics.

[5]  Chen S. Tsai.  Titanium-Indiffused Proton-Exchanged Microlens-Based Integrated Optic Bragg Modulator Modules For Optical Computing , 1986, Other Conferences.

[6]  R Ulrich,et al.  Measurement of thin film parameters with a prism coupler. , 1973, Applied optics.

[7]  K. Tatsumi,et al.  Wide field angle bi-aspherical waveguide lens in LiNbO3 fabricated by proton-exchange , 1988 .

[8]  H.F. Taylor.  Application of guided-wave optics in signal processing and sensing , 1987, Proceedings of the IEEE.

[9]  B. Chen,et al.  Integrated Optic Spectrum Analyzer , 1980, Other Conferences.

[10]  H. Nishihara,et al.  An integrated-optic Fourier processor using an acoustooptic deflector and Fresnel lenses in As2S3waveguide , 1983, Journal of Lightwave Technology.

[11]  T. Suhara,et al.  An integrated-optic disk pickup device , 1986 .

[12]  L. Boivin.  Thin-Film Laser-to-Fiber Coupler. , 1974, Applied optics.

[13]  G. Hatakoshi,et al.  Grating lenses for integrated optics. , 1978, Optics letters.

[14]  Robert A. Sprague.  A Review of Acousto-Optic Signal Correlators , 1977 .

[15]  Pierre Gidon,et al.  Integrated optical spectrum analyser using planar technology on oxidised silicon substrate , 1983 .