Grating Couplers for Coupling between Optical Fibers and Nanophotonic Waveguides

Taillaert, Dirk; Laere, Frederik Van; Ayre, M.; Bogaerts, Wim; Thourhout, Dries Van; Bienstman, Peter; Baets, Roel

doi:10.1143/jjap.45.6071

Cited by 641 publications

(407 citation statements)

References 21 publications

Supporting

Mentioning

383

Contrasting

Unclassified

Order By: Relevance

“…Th e period needed for out-of-plane coupling with diff raction angle θ (the angle of the output light to the surface normal of the SOI wafer) is calculated from the phase matching condition. For most of the grating couplers demonstrated to date, the optical fi ber is orientated with an angle θ of about 10° [58]. Th is is to avoid the large second-order Bragg back refl ection, which would otherwise refl ect about half of the optical power back into the waveguide.…”

Section: Fiber-chip Couplingmentioning

confidence: 99%

“…Although several diff erent designs of fi ber-to-chip grating couplers have been demonstrated, including shallow-etched gratings [57][58][59], slanted gratings [60] and metallic gratings [61], the coupling effi ciency reported for practical implementations and experimental measurements of those designs is limited to around 40%. Two main factors limit the coupling effi ciency of grating couplers.…”

Section: Fiber-chip Couplingmentioning

confidence: 99%

See 1 more Smart Citation

Device engineering for silicon photonics

Chen

Tsang

2011

NPG Asia Mater

View full text Add to dashboard Cite

A fter an impressive initial spurt of progress in device engineering during the early 2000s when the optical communications industry saw unprecedented levels of investment, silicon photonics continues to develop at an amazing pace. Many novel applications and devices are emerging. Silicon photonics has the potential to become a major platform for optoelectronic integrated circuits (OEICs) and to be used in high-speed optical interconnects for chip-level data communications because of the extremely large bandwidth and high speed off ered by optical communications. Many challenges have been addressed through the introduction of innovative ideas, paving the way for the practical deployment of silicon-based optoelectronic devices and integrated photonic circuits in computing and telecommunication systems [1]. Th e commercialization of silicon photonics, originally driven by applications in telecommunications, is now also driven by the needs of the computing industry for highspeed, energy-effi cient optical cable technology, such as the Light Peak Technology under development by Intel (USA). Th e California-based company Luxtera (USA) has also commercialized a series of siliconphotonic transceiver systems.Silicon off ers many advantages over alternative material systems (e.g. InP, GaAs, LiNbO 3 ) for OEIC applications. One major reason for the wide interest that silicon photonics is attracting is the cost advantage that silicon photonics can potentially off er through its compatibility with the complementary metal-oxide-semiconductor (CMOS) fabrication processes used in the microelectronics industry. Th e huge investments that have been made in CMOS microelectronics fabrication technologies has resulted in processes that off er much higher yield than is possible using alternative materials for photonics, thus making feasible large-scale integration and the production of silicon-photonic devices that are monolithically integrated with not only optical components but also electronic circuits in the same platform at ultrahigh density. Another reason for the attractiveness of silicon photonics is the high refractive index contrast between the silicon core (refractive index, 3.48) and silicon dioxide cladding (refractive index, 1.45) in silicon-on-insulator (SOI) devices, which ensures the submicrometer confi nement of light and allows tight bending in optical waveguides. Th e high-density integration of photonic circuits on SOI platforms is thus feasible. Th e low cost of high-quality SOI wafers is another advantage of silicon photonics. All kinds of low-cost devices enabled by silicon photonics are therefore predicted, and these may also enjoy the other benefi ts of monolithic integration: smaller size, increased power effi ciency and improved reliability. Figure 1 shows an example of a high-density integrated photonics devices fabricated on a 6-inch SOI wafer using CMOS-compatible technology.In this article, we review some of the exciting progress that has been made in silicon photonics with the aim of providing a broa...

show abstract

Section: Fiber-chip Couplingmentioning

confidence: 99%

Section: Fiber-chip Couplingmentioning

confidence: 99%

Device engineering for silicon photonics

Chen

Tsang

2011

NPG Asia Mater

View full text Add to dashboard Cite

show abstract

“…Grating couplers were used to couple TE polarized light from a single mode optical fiber into the waveguides. The single mode waveguides were adiabatically tapered to a broad waveguide of 10 µm in order to increase the coupling efficiency to a single mode optical fiber [9]. Apart from efficient light coupling, the grating couplers are highly polarization sensitive any polarization conversion in the micro-bends can be measured as transmission loss from the waveguides.…”

Section: Photonic Test Structurementioning

confidence: 99%

Loss reduction in silicon nanophotonic waveguide micro-bends through etch profile improvement

Selvaraja

Bogaerts

Thourhout

2011

Optics Communications

Self Cite

View full text Add to dashboard Cite

Single mode silicon photonic wire waveguides allow low-loss sharp micro-bends, which enables compact photonic devices and circuits. The circuit compactness is achieved at the cost of loss induced by micro-bends, which can seriously affect the device performance. The bend loss strongly depends on the bend radius, polarization, waveguide dimension and profile. In this paper, we present the effect of waveguide profile on the bend loss. We present waveguide profile improvement with optimized etch chemistry and the role of etch chemistry in adapting the etch profile of silicon is investigated. We experimentally demonstrate that by making the waveguide sidewalls vertical, the bend loss can be reduced up to 25% without affecting the propagation loss of the photonic wires. The bend loss of a 2 µm bend has been reduced from 0.039dB/90 o bend to 0.028dB/90 o bend by changing the sidewall angle from 81 o to 90 o respectively. The propagation loss of 2.7 ± 0.1dB/cm and 3 ± 0.09dB/cm was observed for sloped and vertical photonic wires respectively was obtained.

show abstract

“…This escalates the cost of the overall chip production and hinders global ambition of the fiber to the home, 'FTTH'. Therefore, researchers have considered some new types of spot size converters such as tapered waveguide structures (Tsuchizawa et al 2005; Haxha et al 2006; Bakir et al 2010; Fang et al 2010; Tokushima et al 2012, and grating couplers (Taillaert et al 2002(Taillaert et al , 2006, to overcome the stringent alignment issues.…”

Section: Introductionmentioning

confidence: 99%

Improved design for SOI based evanescently coupled multilayer spot-size converter

2017

View full text Add to dashboard Cite

This is the accepted version of the paper.This version of the publication may differ from the final published version. Permanent repository link AbstractWe report an improved version of a spot size converter (SSC) consisting of a silicon nanowire evanescently coupled to a phase matched Poly Si multilayer structure. With wider transversal dimensions the multilayer structure expands the mode significantly thus increasing the coupling efficiency with the conventional single mode fiber. Detailed optimization process of a 17 layer based SSC is discussed and its coupling efficiency with a high NA fiber of radius 2 μm is obtained as 98% providing only 0.087 dB loss. Vertical alignment tolerance between the optimized SSC and a high NA fiber of radius 2 μm is also shown. This novel design does not consist of a taper and can be fabricated by using CMOS compatible process. It has a short device length and more relaxed alignment tolerances with the fiber. Full vectorial and computationally efficient finite element method and the least squares boundary residual method have been used for the analysis and optimization of the proposed structure.

show abstract

Grating Couplers for Coupling between Optical Fibers and Nanophotonic Waveguides

Cited by 641 publications

References 21 publications

Device engineering for silicon photonics

Device engineering for silicon photonics

Loss reduction in silicon nanophotonic waveguide micro-bends through etch profile improvement

Improved design for SOI based evanescently coupled multilayer spot-size converter

Contact Info

Product

Resources

About