Efficient 52 µm wavelength fiber-to-chip grating couplers for the Ge-on-Si and Ge-on-SOI mid-infrared waveguide platform (original) (raw)
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Optics …, 2010
A new generation of Silicon-on-Insulator fiber-to-chip grating couplers which use a silicon overlay to enhance the directionality and thereby the coupling efficiency is presented. Devices are realized on a 200 mm wafer in a CMOS pilot line. The fabricated fiber couplers show a coupling efficiency of −1.6 dB and a 3 dB bandwidth of 80 nm. out-of-plane grating coupler for efficient butt-coupling between compact planar waveguides and single-mode fibers," IEEE J. Quantum Electron. 14, 949-955 (2002).
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HAL (Le Centre pour la Communication Scientifique Directe), 2016
We report our latest advances in development of high-efficiency fiber-chip surface grating couplers with refractive index engineered subwavelength structures. We present different experimental demonstrations of high-performance gratingcoupled optical interfaces, developed on the standard 220-nm silicon-on-insulator technology in the near-infrared wavelengths.
Sub-wavelength grating components for integrated optics applications on SOI chips
Optics express, 2014
In this paper we demonstrate silicon on insulator (SOI) sub-wavelength grating (SWG) optical components for integrated optics and sensing. Light propagation in SWG devices is studied and realized with no cladding on top of the waveguide. In particular, we focused on SWG bends, tapers and directional couplers, all realized with compatible geometries in order to be used as building blocks for more complex integrated optics devices (interferometers, switches, resonators, etc.). Fabricated SWG tapers for TE and TM polarizations are described; they allow for connecting SWG devices to regular strip waveguides with loss lower than 1 dB per taper. Our SWG directional coupler presents a very compact design and a negligible wavelength dependence of its crossover length (and as a consequence of its coupling coefficient, κ), over a 40 nm bandwidth. This wavelength flatten response represents a bandwidth enhancement with respect to standard directional couplers (made using strip or rib waveguide...
Grating-Assisted Fiber to Chip Coupling for SOI Photonic Circuits
Applied Sciences, 2018
Fiber to chip coupling is a critical aspect of any integrated photonic circuit. In terms of ease of fabrication as well as wafer-scale testability, surface grating couplers are by far the most preferred scheme of the coupling to integrated circuits. In the past decade, considerable effort has been made for designing efficient grating couplers on Silicon-on-Insulator (SOI) and other allied photonic platforms. Highly efficient grating couplers with sub-dB coupling performance have now been demonstrated. In this article, we review the recent advances made to develop grating coupler designs for a variety of applications on SOI platform. We begin with a basic overview of design methodology involving both shallow etched gratings and the emerging field of subwavelength gratings. The feasibility of reducing footprint by way of incorporating compact tapers is also explored. We also discuss novel grating designs like polarization diversity as well as dual band couplers. Lastly, a brief descri...
Compact efficient broadband grating coupler for silicon-on-insulator waveguides
Optics Letters, 2004
We have designed a high-efficiency broadband grating coupler for coupling between silicon-on-insulator (SOI) waveguides and optical fibers. The grating is only 13 mm long and 12 mm wide, and the size of the grooves is optimized numerically. For TE polarization the coupling loss to single-mode fiber is below 1 dB over a 35-nm wavelength range when using SOI with a two-pair bottom ref lector. The tolerances to fabrication errors are also calculated.
Surface Grating Coupled Low Loss Ge-on-Si
Germanium-on-silicon is a highly promising platform for planar photonics for the mid-infrared, due to germanium's wide transparency range. In this paper we report Ge-on-Si waveguides with record low losses of only 0.6dB/cm, which is achieved by using a 2.9 µm thick germanium layer, thus minimizing mode interaction with dislocations at the germanium/silicon interface. Using these waveguides multimode interferometers with insertion losses of only 0.21 ± 0.02 dB are also demonstrated.
High resolution, high channel count mid-infrared arrayed waveguide gratings in silicon
Optics Letters, 2020
Arrayed waveguide gratings (AWGs) working in the 4.7 µm wavelength range are reported on silicon-on-insulator waveguides with 1500 nm thick silicon and 2 µm thick buried oxide layers. For eight channel devices, three different channel spacings (200 GHz, 100 GHz, and 50 GHz) with cross talk levels of − 32.31 d B , − 31.87 d B , and − 27.28 d B and insertion loss levels of − 1.43 d B , − 4.2 d B , and − 2.3 d B , respectively, are demonstrated. Fourteen channel AWGs with 170 GHz channel spacing and 16 channel AWGs with 87 GHz channel spacing are shown to have a cross talk value of − 21.67 d B and − 24.30 d B and insertion loss value of − 4.2 d B and − 3.8 d B , respectively. Two AWGs with 10 nm difference in channel peak are designed, and the measurements show a 9.3 nm difference. The transmission spectrum shift as a function of temperature is found to be 0.22 nm/°C.