We have fabricated a TE mode InGaAsP active waveguide optical isolator based on the nonreciprocal loss shift in an optical fiber telecommunication wavelength of 1550nm. We demonstrated a TE mode nonreciprocal loss shift of 9.3dB/mm under a magnetic field of +/-1kG in the facricated InGaAsP active waveguide with Fe on an InP substrate at a wavelength of 1560nm. This result opens a way to the monolithic integration of semiconductor-waveguide-type optical isolators with edge emitting semiconductor lasers.

Wafer bonding of a magnetooptic garnet crystal to III-V compound semiconductor and LiNbO3 is discussed for the application to waveguide optical isolators. Two types of waveguide isolators, an interferometric isolator and a semileaky isolator, are discussed. The interferometric isolator uses nonreciprocal phase shift and is composed of the GaInAsP guiding layer. The isolator has the advantage of integratability with optical active devices. The semileaky isolator composed of a magnetooptic garnet guiding and LiNbO3 upper cladding layer has the advantages of large fabrication tolerance and wide operating wavelength range. The performance of isolators is also demonstrated.

The effect of non-reciprocal loss/gain in semiconductor-ferromagnetic-metal hybrid was studied. It is shown that the optical loss/gain of this semiconductor-ferromagnetic-metal hybrid differs for the forward and backward propagation when the magnetization is perpendicular to the light propagation and lies in the film plane. Using this effect a new design of optical isolator is proposed, which is beneficial for monolithic integration of optical isolator with laser diode. The non-reciprocal loss was experimentally observed in Ga1-xAlxAs waveguide covered by Co for the first time.

We report on theoretical analysis of magneto-optically induced longitudinal perturbations in chirped magneto-optical Bragg gratings. The induced perturbations considered are of Lorentzian shape, with a spatial extent considerably larger than the spatial grating period but at least an order of magnitude less than the geometrical length of the grating. In the numerical simulation of the proposed device, we show on a high polarization state selectivity in the region of the perturbation, with resonance peaks of transmission for circularly polarized orthogonal components possessing a full width at half maximum as narrow as 0.18 nm, meanwhile being separated by 0.6 nm.

The Si3N4/FePt/Si3N4/Al/Si structures have been fabricated. 57 nm silicon nitride films have been used as dielectric layer for heat dissipation and 500 nm Al film used for reflection layer. The Kerr rotation angle was changed with the FePt layer thickness. At the 65 % Pt composition in 10 nm FePt layer, the maximum Kerr rotation angle was 0.82°. As increase with FePt thickness the Kerr angle is slightly decreased. The change of Kerr rotation angle and the thermal behavior of multilayered structure according to FePt thickness variation were also calculated by computer simulation.

A family of rare-earth metal manganites are antiferromagnetic (AFM) ferroelectrics and some of these may show also weak ferromagnetism. First we will show how to observe the ferroelectric (FEL) and AFM domain structures by the interference effects of second harmonic generation (SHG). Second, the observed clamping of the AFM domain wall (DW) to the FEL domain boundary (DB) is intuitively explained by the group theoretical consideration of the magnetic anisotropy energy depending upon the sign of the FEL polarization. Third, the application of these clamped DW-DB to the memory engineering will be briefly discussed.

We have fabricated three-dimensional magnetophotonic (3D MPCs) crystals based on artificial opals. Structural and magnetic properties of 3D MPCs were studied by field emission scanning electron microscopy, x-ray diffraction analysis, and vibrating sample magnetometer. It was shown that increase of volume fraction of magnetite in the opal lattice leads to a dramatic decrease of transmitted light intensity in the visible region. We also found considerable changes in the Faraday rotation inside the (111) photonic bandgap of an opal—magnetite magnetophotonic crystal.

A new type of photonic crystals entitled “magnonic crystals (MC)” that exhibit forbidden gaps in the microwave spectrum of magnetostatic spin waves (MSW) are reported. The topography of the MCs that consist of two-dimensional (2-D) etched holes periodic structure in yttrium iron garnet films was studied by atomic force and magnetic force magnetometry. The propagation characteristics of spin waves in such 2-D MCs was measured and analyzed.

Magnetic photonic crystals are spatially periodic dielectric composites with at least one of the constitutive components being a magnetically polarized material. Magnetic polarization, either spontaneous or induced, is always associated with nonreciprocal circular birefringence (Faraday rotation), which can bring qualitatively new features to the electrodynamics of photonic crystals. If the geometry of the periodic array meets certain symmetry criterion, the electromagnetic properties of the composite appear similar to those of a hypothetical bianisotropic medium with gigantic linear magnetoelectric effect. In particular, such a photonic crystal can display sptrong spectral asymmetry, which implies that electromagnetic waves propagate from left to right significantly faster or slower than from right to left. The strong spectral asymmetry can result in the phenomenon of electromagnetic unidirectionality. A lossless unidirectional medium, being perfectly transmissive for electromagnetic wave of certain frequency, “freezes” the radiation of the same frequency propagating in the opposite direction. The frozen mode is a coherent Bloch wave with nearly zero group velocity and drastically enhanced amplitude. The phenomenon of electromagnetic unidirectionality is essentially nonreciprocal and unique to gyrotropic photonic crystals. Physical conditions for the phenomenon include (i) significant Faraday rotation in the magnetic component of the composite structure at the frequency range of interest and (ii) the proper spatial arangement of the constituents. Unidirectional photonic crystals can be very attractive for a variety of applications.

Diluted magnetic semiconductor Cd1-xMnxTe was proposed as a magneto-optic material for waveguide optical isolator. Waveguide propagation loss below 1 dB/cm, complete magneto-optical mode conversion and optical isolation of 20 dB were demonstrated with Cd1-xMnxTe waveguides grown on GaAs substrate. The high isolation ratio, high magneto-optic effect and low propagation loss achieved in the magneto-optical waveguide grown on the semiconductor substrate shows the feasibility of monolithical integration of an optical isolator with semiconductor optoelectronic devices.

Charge transport and optical properties have been studied experimentally and theoretically in a series of LaGa1-xMnxO3 crystals in the dependence on the material composition. Electron energy structure and optical functions of LaGa1-xMnxO3 are calculated by ab initio pseudopotential method within density functional theory using generalized gradient approximation. Theoretical results are discussed in comparison with the experimental data for different alloy compositions.

The fabrication of one-dimensional magnetophotonic crystals (MPC) composed from Bi-substituted yttrium-iron-garnet films separated by the silicon oxide layers is presented. The enhancement of the Faraday rotation angle is observed at the spectral regions of the photonic band gap edges. The effective Faraday rotation achieves the values up to 1.5 degrees per micron at 1100-nm-wavelength.

In this paper, the results of experimental studies of magnetization-induced second- and third-order nonlinear optical effects in magnetic nanogranular films are described. Magnetization-induced variations of the intensity, polarization state and the phase of the harmonics' waves are observed in magnetic nanogranular films of the composition CoxAg1-x and Cox(Al2O3)1-x. Nonlinear magneto-optical Kerr effect (NOMOKE) in third-harmonic generation is observed in these nanomaterials. The second- and third-order NOMOKE from granular films is shown to exceed the linear magneto-optical Kerr effect by at least an order of magnitude.