Theory of a Directive Optical Leaky Wave Antenna Integrated into a Resonator and Enhancement of Radiation Control (original) (raw)
Related papers
Enhancing radiation control of an optical leaky wave antenna in a resonator
2012
abstract We analyze the theoretical and physical properties of a CMOS compatible optical leaky wave antenna (OLWA) integrated into a Fabry-Pérot resonator (FPR) at 193.4 THz (wavelength< i> λ< sub> 0= 1550 nm). The presented OLWA design is composed of a silicon (Si) dielectric waveguide sandwiched between two silica glass (SiO< sub> 2) domains, and it comprises periodic perturbations (cavities of vacuum).
Theory of Optical Leaky-Wave Antenna Integrated in a Ring Resonator for Radiation Control
Journal of Lightwave Technology
The integration of a leaky-wave antenna with a ring resonator is presented using analytical guided wave models. The device consists of a ring resonator fed by a directional coupler, where the ring resonator path includes a leaky-wave antenna segment. The resonator integration provides two main advantages: the high-quality factor ensures effective control of radiation intensity by controlling the resonance conditions and the efficient radiation from a leaky-wave antenna even when its length is much smaller than the propagation length of the leaky wave. We devise an analytical model of the guided wave propagation along a directional coupler and the ring resonator path including the antenna and non-radiating segments. The trade-offs regarding the quality factor of resonance and the antenna efficiency of such a design is reported in terms of the coupler parameters, leaky-wave constant and radiation length. Finally a CMOS-compatible OLWA design suitable for the ring resonator integration is designed where Silicon is utilized as the waveguide material for a possible electronic control of radiation intensity. The simulation results together with the analytical model show that slight variations in the leaky-wave's propagation constant, realized through excitation of excess carriers in Si domain, is sufficient to control the far-field radiation modulation with high extinction ratio.
Optics Express, 2012
We investigate the directive radiation at 1550 nm from an optical leaky wave antenna (OLWA) with semiconductor perturbations made of silicon (Si). We study the radiation pattern dependence on the physical dimensions, number of perturbations and carrier densities in these semiconductor perturbations through optical excitations at a visible wavelength, 625 nm. In this detailed theoretical study we show the correlation between the pump power absorbed in the perturbations, the signal guided in the waveguide and the radiation through leakage. To overcome the limited control of the radiation intensity through excess carrier generation in Si, we present a new design with the OLWA integrated with a Fabry-Pérot resonator (FPR). We provide analytical and numerical studies of the enhanced radiation performance of the OLWA antenna inside the FPR, and derive closed-form formulas accounting for LW reflection at the edges of the FPR. A discussion on the constructive and destructive radiation by the direct and reflected leaky waves in the FPR resonator is provided. Results shown in this paper exhibit 3 dB variation of the radiation and pave the way for further optimization and theoretical developments.
Optical leaky-wave antenna integrated in ring resonator
2014 IEEE Antennas and Propagation Society International Symposium (APSURSI), 2014
A leaky-wave antenna at optical frequencies is designed and integrated with a ring resonator at 1550 nm wavelength. The leaky wave is generated by using periodic perturbations in the integrated dielectric waveguide that excite the-1 spatial harmonic. The antenna consists of a dielectric waveguides with semiconductor corrugations, and it is compatible with CMOS fabrication technology. We show that integrating the leaky wave antenna in an optical ring resonator that is fed by directional couplers, we can improve the electronic control of the radiation through carrier injection into the semiconductor corrugations. I.
Performance of Modified Silicon-Based Optical Leaky-Wave Antenna Structures
INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY
Conventional silicon-based optical leaky-wave antennas (OLWAs) have been investigated in the literature as high directivity narrow-beam radiators with steering capability and designed for 1550 nm operation using single-grating layer. In this paper, two modifications are introduced to the conventional silicon-based OLWA. The first modification is to redesign the structure for 1300 nm operation and to compare the radiation parameters with those of the 1550 nm counterpart. The second modification is to design and investigate the performance of a double-grating OLWA which is useful for double-beam steering.