共查询到20条相似文献,搜索用时 15 毫秒
1.
A waveguide optical isolator with a CeY2Fe5O12 guiding layer employing a nonreciprocal phase shift was studied.The isolation ratio of more than 12.2 dB was achieved at a wavelength of 1.55 μm. 相似文献
2.
Selective oxidation of an AlInAs layer was investigated for enhancement of magneto-optic effect in an optical isolator. Twelve times nonreciprocal phase shift enhancement was estimated from a measured AlInAs-oxide refractive index. 相似文献
3.
Design and simulation of magneto-optic Mach-Zehnder isolator 总被引:1,自引:0,他引:1
In this paper, we have designed, optimized and simulated the magneto-optic Mach-Zehnder isolator. The waveguide isolator is based on a nonreciprocal phase shift in the magneto-optic branch of the MZ isolator. We have used the finite difference beam propagation method for numerical solution of the scalar wave equation. We have also used the transparent boundary condition. The propagation constant has been achieved by using the effective index method. We have calculated the design parameters to decrease the insertion loss in the forward direction and increase return loss in the backward direction and achieved a 40 dB isolation ratio. 相似文献
4.
A design is described for a nonreciprocal phase shifter, which is the key element in the constitution of a Mach-Zehnder interferometric isolator consisting of a magneto-optical channel waveguide. A four-layered structure waveguide is dealt with in which a cover layer having a larger refractive index than that of the film is placed on the magneto-optic thin film; it is revealed that the phase shifter length can be shortened by up to 6 mm at the 1.15 m wavelength, which is half the length of a nonreciprocal phase shifter constructed of a three-layered waveguide without a large refractive index cover layer. Two types of channel waveguides are investigated: a rib waveguide and a strip-loaded waveguide; they are found to have the same phase shifter length for the optimum condition. 相似文献
5.
Gishamol Mathew Anju Babu Jesly Jacob Vincent Mathew 《Superlattices and Microstructures》2008,44(2):203-207
This paper discusses the magneto-optic phase shift in garnet/semiconductor-on-insulator plasmonic waveguides. We consider two structures: (1) Y IG/Si/SiO2 and (2) Y IG/GaInAsP/AlInAs-oxide. A dispersion relation for the plasmon propagation has been derived and the nonreciprocal phase shift of the fundamental TM mode has been determined at wavelengths of 1.55 μm, 1.5 μm and 1.3 μm. 相似文献
6.
Ruiyi Chen 《Optics Communications》2009,282(5):862-866
This paper presents an asymmetric multimode interference-based (MMI) optical isolator, by utilizing the magneto-optical nonreciprocal phase shift (NPS). Equivalent beam propagation method (BPM) simulation of symmetric and asymmetric isolators are performed using configuration of Air/Ce:YIG/SiO2 on silicon substrate for integration. The asymmetric isolator is found to be much more compact in size and efficient in isolation compared with symmetric isolator. Simulation results show that the isolation of asymmetric structure is 23.8 dB higher than that of symmetric one. It is mainly because both symmetric mode and anti-symmetric mode are excited in asymmetric structure and hence can interfere destructively. The proposed device may play an important role in the optical communication systems and photonic integrated devices. 相似文献
7.
Bahlmann N. Lohmeyer M. Wallenhorst M. Dötsch H. Hertel P. 《Optical and Quantum Electronics》1998,30(5-6):323-334
Non-reciprocal rib waveguide structures can be used to realize integrated optical isolators. In this paper, we propose a concrete design for a Mach–Zehnder interferometer type isolator for TM modes. Just one of the arms, which are of equal length, is a non-reciprocal magneto-optic waveguide. The rest of the interferometer is reciprocal. Required fabrication tolerances are estimated, and the entire isolator is simulated by applying a finite difference beam propagation method. 相似文献
8.
分析了光的线性双折射对磁光波导TE-TM模式转换,法拉第旋转,波导光隔离器隔离比及插入损耗的影响。研究了掺Bi钇铁石榴石薄膜光波导中的形状线性双折射,应力感生线性双折射及生长感生线性双折射的来源,特性和消除方法。 相似文献
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11.
Yoshiteru Amemiya Tomohiro Tokunaga Yuichiro Tanushi Shin Yokoyama 《Optical Review》2009,16(3):247-251
Electric-field drive optical modulators using a Si ring resonator were fabricated on silicon-on-insulator (SOI) wafers. The
fabricated resonators consisted of Si waveguides with width and thickness of 1.0 and 0.3 μm, respectively. In order to induce
the linear electro-optic (EO) effect in the Si core layer, the strain was applied by covering the layer with Si3N4 film (0.26 μm thick) deposited by low pressure chemical vapor deposition (LPCVD) at 750 °C. The vertical electric-field was
applied to the Si waveguide through the top and bottom cladding layers, and the optical output from the drop port at the resonance
wavelength was measured. At a wavelength of 1501.6 nm, the optical modulation of 33% was obtained at 200V (electric-field
at the silicon surface ∼3 × 105 V/cm, nearly the breakdown field). The resonance wavelength was shifted toward the short wavelength side by applying both
positive and negative voltages, this shift was explained by carrier concentration modulation. The linear EO effect in the
Si core layer was not observed, presumably because the strain in the Si core layer was too small. 相似文献
12.
We present an analytical proof of the existence of unidirectional optical Bloch oscillations in a waveguide array system. It is shown that the presence of nonreciprocity in the system allows for a complete normal-mode dephasing in one of the propagation directions, resulting in a unidirectional breakdown in Bloch oscillations. A model system consisting of an array of transversely magnetized asymmetric Si/SiO2 waveguides with a magneto-optic cover layer is presented. Large index contrasts between film and cover are critical for practical realizations. 相似文献
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14.
We theoretically investigated InGaAsP/InP evanescent mode waveguide optical isolators and proposed their application to InGaAsP/InP/Si
hybrid evanescent optical isolators. InGaAsP/InP evanescent optical isolators are composed of semiconductor optical amplifier
(SOA) waveguides having InGaAsP multiple quantum well (MQW) active layer and upper InGaAsP waveguide layer with ferromagnetic
layer. Optical isolation is obtained for evanescent optical mode in the InGaAsP waveguide layer. InGaAsP/InP/Si hybrid evanescent
optical isolators are theoretically proposed based on the idea of InGaAsP/InP evanescent optical isolators. InGaAsP/InP/Si
hybrid evanescent optical isolators are composed of ferromagnetic metal loaded silicon evanescent waveguides with wafer-bonded
InGaAsP/InP optical gain material. The optical isolation and propagation loss are discussed with the structure of silicon
evanescent waveguides, and optical isolation of 8.0 dB/mm was estimated. The concept of semiconductor evanescent mode optical
isolators is feasible with InP based photonic integrated circuits and advanced silicon photonics. 相似文献
15.
M. A. Andreeva E. P. Domashevskaya E. E. Odintsova V. A. Terekhov S. Yu. Turishchev 《Journal of synchrotron radiation》2012,19(4):609-618
The general matrix theory of the photoelectron/fluorescence excitation in anisotropic multilayer films at the total reflection condition of X‐rays has been developed. In a particular case the theory has been applied to explain the oscillation structure of L2,3 XANES spectra for a SiO2/Si/SiO2/c‐Si sample in the pre‐edge region which has been observed by a sample current technique at glancing angles of synchrotron radiation. Remarkably the phase of the oscillations is reversed by a ~2° angle variation. The observed spectral features are found to be a consequence of waveguide mode creation in the middle layer of strained Si, which changes the radiation field amplitude in the top SiO2 layer. The fit of the data required the correction of the optical constants for Si and SiO2 near the Si L2,3‐edges. 相似文献
16.
In advanced optical fiber communication systems where reflection light might cause degradation of the signal quality, optical waveguide isolators play an important role. The effect of a metal layer with negative permittivity on the behavior of nonlinear-magnetooptic isolator is studied. The isolator consists of metal film, nonlinear cladding, and magnetooptic substrate. It is found that difference between forward and backward propagation for TM0 mode increases with increasing the absolute value of the tuning parameter which is the permittivity of the metal film, ?f. It is also found that the maximum cut-off thickness of the isolator occurs in self-defocusing case around η = 0.65 and at the highest assumed value of ?f = −8. These results are helpful in fabricating an isolator with high performance. 相似文献
17.
A. Sticht E. Neufeld A. Luigart K. Brunner G. Abstreiter H. Bay 《Journal of luminescence》1998,80(1-4):321-327
In this paper we demonstrate electroluminescence from erbium- and oxygen doped Si and SiGe diodes in surface emitting and waveguiding geometry. The layers were deposited by molecular beam epitaxy (MBE) on (1 0 0)Si. A series of samples with varying Er : O-doped layer thickness was grown, showing a decrease in luminescence intensity for layers thinner than 80 nm. The current–voltage characteristics and luminescence properties of another series of samples with varying Ge content were examined. They are probably influenced by strain relaxation at large Ge content. Si/SiGe waveguides were processed and their emission was analyzed by a confocal microscope setup. The spatially narrow emission and the dependence of luminescence on waveguide length proved optical guiding of the erbium emission. 相似文献
18.
We propose a new isolator structure for MT modes using the non-reciprocal phase shift of an asymmetric magnetooptic waveguide. The new design does not require phase matching between a magnetooptic and an anisotropic material. The required waveguide length, however, is larger than in previously suggested designs. 相似文献
19.
We have analysed the mode structure of a wideband radiofrequency excited waveguide CO2 laser by using different waveguide diameters and optical cavities. In particular we have observed the phase shift of some linear polarized waveguide modes in the transition region between the guided and the free Gaussian propagation. 相似文献
20.
A new all-fiber-optic nonreciprocal device using two acousto-optic frequency shifters is proposed and demonstrated. When the device was operated as an optical isolator, an extinction ratio of 22 dB was obtained. The device's unique modulation capability is also described. 相似文献