Focusing-curved subwavelength grating couplers for ultra-broadband silicon photonics optical interfaces.

We report on the design and characterization of focusing-curved subwavelength grating couplers for ultra-broadband silicon photonics optical interfaces. With implementation of waveguide dispersion engineered subwavelength structures, an ultra-wide 1-dB bandwidth of over 100 nm (largest reported to date) near 1550 nm is experimentally achieved for transverse-electric polarized light. By tapering the subwavelength structures, back reflection is effectively suppressed and grating coupling efficiency is increased to -4.7 dB. A compact device footprint of 40 µm × 20 µm is realized by curving the gratings in a focusing scheme.

[1]  Siegfried Janz,et al.  Recent Advances in Silicon Waveguide Devices Using Sub-Wavelength Gratings , 2014, IEEE Journal of Selected Topics in Quantum Electronics.

[2]  Siegfried Janz,et al.  Subwavelength grating crossings for silicon wire waveguides. , 2010, Optics express.

[3]  Wei Shi,et al.  Fully etched grating coupler with low back reflection , 2013, Other Conferences.

[4]  T Pinguet,et al.  A Grating-Coupler-Enabled CMOS Photonics Platform , 2011, IEEE Journal of Selected Topics in Quantum Electronics.

[5]  Wei Shi,et al.  An ultra-broadband fiber grating coupler with focusing curved subwavelength structures , 2014, OFC 2014.

[6]  Ke Xu,et al.  Focusing subwavelength grating coupler for mid-infrared suspended membrane waveguide. , 2012, Optics letters.

[7]  Roel Baets,et al.  Compact grating couplers on silicon-on-insulator with reduced backreflection. , 2012, Optics letters.

[8]  Shih-Lin Chang,et al.  Three-layer 1.3 µm In 1-x Ga x As y P 1-y lasers with quaternary confining layers , 1981 .

[9]  Pieter Dumon,et al.  Two-Dimensional, 37-Channel, High-Bandwidth, Ultra-Dense Silicon Photonics Optical Interface , 2015, Journal of Lightwave Technology.

[10]  K. Yvind,et al.  Ultra-low-loss inverted taper coupler for silicon-on-insulator ridge waveguide , 2010 .

[11]  Jing Zhang,et al.  Bandwidth analysis of waveguide grating coupler. , 2013, Optics Express.

[12]  Michael Hochberg,et al.  Towards fabless silicon photonics , 2010 .

[13]  Yun Wang.  Grating coupler design based on silicon-on-insulator , 2013 .

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

[15]  Ashok V. Krishnamoorthy,et al.  Silicon photonics: Energy-efficient communication , 2011 .

[16]  Ray T. Chen,et al.  Colorless grating couplers realized by interleaving dispersion engineered subwavelength structures , 2013, CLEO: 2013.

[17]  D. Van Thourhout,et al.  Compact Focusing Grating Couplers for Silicon-on-Insulator Integrated Circuits , 2007, IEEE Photonics Technology Letters.

[18]  Siegfried Janz,et al.  Continuously apodized fiber-to-chip surface grating coupler with refractive index engineered subwavelength structure. , 2010, Optics letters.

[19]  Ke Xu,et al.  Broadband focusing grating couplers for suspended-membrane waveguides. , 2012, Optics letters.

[20]  H. Tsang,et al.  Apodized Waveguide Grating Couplers for Efficient Coupling to Optical Fibers , 2010, IEEE Photonics Technology Letters.

[21]  A Bräuer,et al.  Efficient coupling into polymer waveguides by gratings. , 1997, Applied optics.

[22]  Ke Xu,et al.  Wideband subwavelength gratings for coupling between silicon-on-insulator waveguides and optical fibers. , 2012, Optics letters.

[23]  P. Cheben,et al.  Gradient-index antireflective subwavelength structures for planar waveguide facets. , 2007, Optics letters.

[24]  Feng Luan,et al.  Design for broadband high-efficiency grating couplers. , 2012, Optics letters.