Abstract: A polarization insensitive fiber laser. A pair of 45 degree Faraday rotators are positioned on either end of the fiber gain source. The resulting laser is insensitive to external perturbations with respect to known entrance and exit polarization states of the laser light. Modelocking, both passive and active, is possible. Configuration wherein the fiber is a combination of polarization preserving and Erbium-doped, and a saturable absorber is included provide a self-starting, polarization insensitive modelocked laser.

Abstract: At least one non-reciprocal rotation element is interposed between two adjacent walk off crystal members to form an optical isolator. Light in the forward direction is separated into two rays of linear polarizations where there is substantially no optical path length difference between the two rays. Light transmitted in the reverse direction is reduced. A conventional optical isolator which does not preserve optical path length difference is converted into one which does by adding a birefringent plate to compensate for the optical path length difference introduced by the conventional isolator. A pair of collimating lenses may be introduced between any pair of non-reciprocal rotation elements.

Abstract: An optical non-reciprocal device is disclosed for passing light in the forward direction and for reducing light passing in the reverse direction. Three anisotropic crystal members are arranged in a linear array. Each member has a walk off direction for separating light into ordinary and extraordinary rays. At least one non-reversible rotation element is interposed between every two adjacent anisotropic crystal members. Rotations of the elements and the orientations and thicknesses of the anisotropic crystal members are such that light in the forward direction is separated into ordinary and extraordinary rays which substantially do not superpose each other upon emerging from the device so that light passing in the reverse direction is reduced in a manner which is substantially insensitive to temperature and wavelengths of the light passing in either direction.

Abstract: A magnetostatic wave structure in which magnetostatic wave signals are coupled between discrete magnetostatic wave elements without the use of microstrip transducers. This structure consists of a plurality of blocks of ferrimagnetic material in which each block has an edge close enough to an edge of another block that a magnetostatic wave in the first of these blocks couples across the gap between these two edges into the second of these blocks. Linear and nonlinear configurations are presented that include a band pass filter.

Abstract: An overcoupled resonator having a resonant cavity defined by a thin film of magnetic material with a pair of end walls parallel to a transducer. Because this resonator is overcoupled, it is suitable for use in a broadband oscillator.

Abstract: In a batch process of manufacturing magnetostatic resonators, photolithographically etching a ferrimagnetic layer, that has been deposited on a dielectric substrate, to produce a plurality of disjoint blocks of ferrimagnetic material. Each block has a pair of sides that are substantially parallel for use in reflecting magnetostatic waves to form a resonator. A conductive layer is deposited on the wafer and then this layer is photolithographically etched to form a transducer adjacent to each of these reflecting sides.