General silicon-on-insulator higher-order mode converter based on substrip dielectric waveguides.

A general silicon mode-converter waveguide that converts a fundamental mode to any higher-order mode is proposed. Specifically, dielectric substrip waveguides are inserted in the fundamental mode propagation path so that the conversion is done directly in the same propagation waveguide, without coupling the power into another waveguide as it happens in traditional mode converters. The device has a very small footprint compared to traditional converters. A mathematical model is developed to determine the design parameters of the used dielectric material and analyze the whole performance of the proposed device. Both the effective index method (EIM) and the perturbative mode-coupled theory are used in our mathematical analysis to get exact values for both the coupling coefficient and the length of the used dielectric material, so as to ensure a maximum coupled power transfer to the higher-order mode. In addition, full vectorial 3D-FDTD simulations are performed to validate our mathematical model. Our results show good agreement between the approximate EIM method and accurate full vectorial 3D-finite-difference time-domain (FDTD) simulations in characterizing the device parameters and performance. In order to validate the design model, two mode converters are simulated, fabricated, and tested for converting a fundamental TE0 mode into both first- and second-order (TE1 and TE2) modes, respectively. Good insertion losses and low crosstalks are obtained. Good agreement between simulated and fabricated results are achieved.

[1]  Karsten Rottwitt,et al.  Broadband higher order mode conversion using chirped microbend long period gratings. , 2016, Optics express.

[2]  H. Ahmad,et al.  Dynamic LP01–LP11 Mode Conversion by a Tilted Binary Phase Plate , 2017, Journal of Lightwave Technology.

[3]  Sailing He,et al.  On‐chip silicon 8‐channel hybrid (de)multiplexer enabling simultaneous mode‐ and polarization‐division‐multiplexing , 2014 .

[4]  Min Qiu,et al.  Effective index method for heterostructure-slab-waveguide-based two-dimensional photonic crystals , 2002 .

[5]  Massimiliano Salsi,et al.  40km transmission of five mode division multiplexed data streams at 100Gb/s with low MIMO-DSP complexity , 2011, 2011 37th European Conference and Exhibition on Optical Communication.

[6]  Kin Seng Chiang,et al.  Analysis of the effective-index method for the vector modes of rectangular-core dielectric waveguides , 1996 .

[7]  Weimin Ye,et al.  Design of broadband silicon-waveguide mode-order converter and polarization rotator with small footprints , 2017 .

[8]  Guodong Chen,et al.  On-chip optical mode conversion based on dynamic grating in photonic-phononic hybrid waveguide , 2015, Scientific Reports.

[9]  Ole Sigmund,et al.  Topology-optimized mode converter in a silicon-on-insulator photonic wire waveguide , 2016, 2016 Conference on Lasers and Electro-Optics (CLEO).

[10]  M. Lipson,et al.  Nanotaper for compact mode conversion. , 2003, Optics letters.

[11]  Daoxin Dai,et al.  Mode conversion in tapered submicron silicon ridge optical waveguides. , 2012, Optics express.

[12]  Daoxin Dai,et al.  Experimental demonstration of simultaneous mode and polarization-division multiplexing based on silicon densely packed waveguide array. , 2015, Optics letters.

[13]  Pavel Cheben,et al.  Ultra-Broadband Mode Converter and Multiplexer Based on Sub-Wavelength Structures , 2018, IEEE Photonics Journal.

[14]  Kazi Tanvir Ahmmed,et al.  Broadband higher-order mode pass filter based on mode conversion , 2017, 2017 Opto-Electronics and Communications Conference (OECC) and Photonics Global Conference (PGC).

[15]  Noa Mazurski,et al.  Dielectric Metasurface as a Platform for Spatial Mode Conversion in Nanoscale Waveguides. , 2016, Nano letters.

[16]  Takehiro Tsuritani,et al.  Performance evaluation of selective mode conversion based on phase plates for a 10-mode fiber. , 2014, Optics express.

[17]  Takehiro Tsuritani,et al.  Selective mode multiplexer based on phase plates and Mach-Zehnder interferometer with image inversion function. , 2015, Optics express.

[18]  J. Nurmi,et al.  Comparison of bulk and SOI CMOS technologies in a DSP processor circuit implementation , 2001, ICM 2001 Proceedings. The 13th International Conference on Microelectronics..

[19]  Fan Zhang,et al.  Broadband silicon photonic directional coupler using asymmetric-waveguide based phase control. , 2015, Optics express.

[20]  Hironori Sasaki,et al.  Silicon wire waveguide TE0/TE1 mode conversion Bragg grating with resonant cavity section. , 2017, Optics express.

[21]  H. Shalaby.  Bi-Directional Coupler as a Mode-Division Multiplexer/Demultiplexer , 2016, Journal of Lightwave Technology.

[22]  K. Bergman,et al.  On-chip mode-division multiplexing switch , 2015 .

[23]  Hossam M H Shalaby,et al.  Modeling, simulation, and fabrication of bi-directional mode-division multiplexing for silicon-on-insulator platform. , 2018, Applied optics.

[24]  Lei Wang,et al.  Low-loss and fabrication tolerant silicon mode-order converters based on novel compact tapers. , 2015, Optics express.

[25]  Mihail M. Dumitrescu,et al.  Effective index method for the computation of the propagation constant and electromagnetic field distribution in z-uniform dielectric or semiconductor waveguides , 1998, ROMOPTO International Conference on Micro- to Nano- Photonics III.

[26]  A. Srivastava,et al.  Silicon-on-Insulator Fundamental to First-Order Dual Polarization Mode Converter based on Si-Si3N4 Phase Plate Waveguide , 2018, 2018 20th International Conference on Transparent Optical Networks (ICTON).

[27]  H. Shalaby.  Bidirectional mode-division multiplexers with antireflection gratings. , 2018, Applied optics.

[28]  Odile Liboiron-Ladouceur,et al.  High-speed two-mode switch for mode-division multiplexing optical networks , 2017 .

[29]  Alok Mehta,et al.  Selective excitation of the LP11 mode in step index fiber using a phase mask , 2006 .

[30]  Amnon Yariv,et al.  Supermodes of grating-coupled multimode waveguides and application to mode conversion between copropagating modes mediated by backward Bragg scattering , 1999 .

[31]  A. Yariv.  Coupled-mode theory for guided-wave optics , 1973 .

[33]  R. K. Varshney,et al.  A simple and accurate model analysis of strip-loaded optical waveguides with various index profiles , 1988 .

[34]  H. Furuta,et al.  Novel optical waveguide for integrated optics. , 1974, Applied optics.

[35]  Wei Li,et al.  Broadband and fabrication-tolerant on-chip scalable mode-division multiplexing based on mode-evolution counter-tapered couplers. , 2015, Optics Letters.