U.S. Philips Corporation

Elke B Pross

Wolfgang F Tolksdorf

Hans O Dammann

Gert Rabe

Inske E Bartels

Manfred B Zinke

Claus-Peter Klages

Hans Damman

Optical isolator, circulator, switch or the like, including a Faraday rotator to which a magnetic field is applied which is oriented along the direction of propagation of light and which is arranged between a preceding polarization filter and a succeeding polarization filter whose planes of polarization enclose an angle with respect to each other such that light can only traverse in one direction, the Faraday rotator having different propagation constants .beta..sub.TE and .beta..sub.TM in a TE plane and a TM plane, respectively. The elaborate technique for adapting the propagation constants of the TE wave and the TM wave is mitigated in that the TE plane of the Faraday rotator is aligned in such a way that it extends between the planes of polarization of the polarization filters.

Optical isolator, circulator, switch or the like, including a faraday

The invention relates to an optical polarization regulator having a wave-guide structure for converting the polarization state of an optical beam passing through and comprising devices for adjusting the coupling constants K of the TE and TM modes of the optical beam and for adjusting the difference .DELTA..beta. of the propagation constants .beta..sub.TE and .beta..sub.TM of these modes. The wave-guide structure is a magnetooptical element (8, 9, 13). The coupling constant K is adjusted by a magnetic field acting upon the wave-guide structure (8, 9, 13) and the difference .DELTA..beta. is adjusted by a mechanical deformation force exerted on the wave-guide structure.

Optical polarization regulator having a wave-guide structure

The invention relates to a magnetooptical waveguide device for the conversion of modes of propagation of the device. The device comprises layers (1, 4, 5, 6, 7) which are epitaxially applied to a substrate layer (8) and of which at least the waveguide layer (1) in which the modes propagate consists of a transparent magnetooptical material for which mode conversion can be induced by a magnetic field. For more accurate matching of the phase velocity of the TE and TM modes this structure is disposed in an apparatus (14, 15) by which an adjustable mechanical deformation force (24, 25) is exerted on the wave guide structure.

Phase-matched magnetooptical mode converter

Planar optical waveguide having a crystal body consisting of a nonmagnetic substrate having a first magnetooptical layer epitaxially provided on the substrate and a second magnetooptical layer epitaxially provided on the first mangetooptical layer. The two magnetooptical layers consist of a material based on iron garnet. The second magnetooptical layer has a refractice index n.sub.2 which is approximately 1.times.10.sup.-3 to 1.times.10.sup.-2 higher than the refractive index n.sub.1 of the first magnetooptical layer. A layer of a material based on iron garnet and absorbing radiation in the wavelength range of 1.0.ltoreq..lambda..ltoreq.2.5 .mu.m is provided between the substrate and the first magnetooptical layer, said iron garnet-based layer having a refractive index n.sub.A which is higher than the refractive index of the first magnetooptical layer.

Planar optical waveguide and method of manufacturing same

Planar optical waveguide comprising a nonmagnetic substrate with a first magnetooptical layer produced epitaxially on the substrate, and a second magnetooptical layer produced epitaxially on the first magnetooptical layer. Both magnetooptical layers are composed of an iron garnet-based material. The second magnetooptical layer has a refractive index n which is approximately 1.times.10.sup.-3 to 1.times.10.sup.-2 greater than the refractive index of the first magnetooptical layer. The material of the magnetooptical layers contains at least one substituent at the dodecahedral sites of the garnet lattice, in particular lead. The proportions of lead are different in the materials of the first and the second magnetooptical layer. The optical waveguide can be used for optical single mode waveguides in the near infrared spectral range (0.8.ltoreq..lambda..ltoreq.1.6 .mu.m).

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Hamburg, Germany

Elke B Pross