Broadband Electro-Optical Crossbar Switches Using Low-Loss Ge2Sb2Se4Te1 Phase Change Material

Leonardis, Francesco De; Soref, Richard A.; Passaro, Vittorio M. N.; Zhang, Yifei; Hu, Juejun

doi:10.1109/jlt.2019.2912669

Cited by 77 publications

(36 citation statements)

References 31 publications

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“…And for the input TM 0 mode, the IL is smaller than 1.31 dB, the CT is less than −27.37 dB, and the PER is larger than 21.37 dB. The performance of our designed SPBS can be improved further if Ge 2 Sb 2 Se 4 Te 1 (GSST) is adopted [22]- [24]. Table 3 summarizes the performance of the introduced SPBS utilizing GST-on-silicon waveguides and the one using GSST-on-silicon waveguides.…”

Section: Tablementioning

confidence: 99%

“…5 that the presented DCGSW consists of a hybrid Si-GST-ITO waveguide and a silicon waveguide. The overlaid ITO which can be connected to metal contact pads at the top surface of the SiO 2 by using sub-micron vias is able to induce the phase change of GST in the hybrid waveguide [22]. The length and width of GST are marked as L g and W 2 , the thicknesses of GST and ITO are labeled as h g and h i , and the gap between the hybrid waveguide and silicon waveguide is denoted by G 2 .…”

Section: Structure Design and Optimizationmentioning

confidence: 99%

“…Here, the widths W 1 = 450 nm and W 2 = 390 nm are selected and the thicknesses h g and h i are chosen to be h g = 20 nm and h i = 50 nm. The complex refractive indexes of the amorphous and crystalline GST and ITO are 3.9831 + 0.024426i, 6.4852 + 1.0544i, and 1.9615 + 0.00559i [22] at 1550 nm wavelength, respectively. To ensure that low CT and IL can be achieved, the length L g and the gap G 2 are optimized.…”

Section: Structure Design and Optimizationmentioning

confidence: 99%

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Switchable Polarization Beam Splitter Based on GST-on-Silicon Waveguides

Dai

et al. 2020

IEEE Photonics J.

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A switchable polarization beam splitter utilizing GST-on-silicon waveguides is introduced and comprehensively investigated in this paper. Based on the phase matching and mode hybridization, structural parameters of the presented device are optimized by using the particle swarm optimization algorithm and finite difference time domain method, so that the output fundamental transverse-electric (TE 0) and transverse-magnetic (TM 0) modes can be switched by controlling the phase state of GST and the device exhibits broad bandwidth, low crosstalk, and high polarization extinction ratio. For the designed device with the amorphous GST, the crosstalk is lower than −23.40 dB and the polarization extinction ratio is larger than 21.35 dB over the C-band. In the case of the crystalline GST, within the C-band, the crosstalk of less than −27.37 dB and the polarization extinction ratio of greater than 21.37 dB are achieved.

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Section: Tablementioning

confidence: 99%

Section: Structure Design and Optimizationmentioning

confidence: 99%

Section: Structure Design and Optimizationmentioning

confidence: 99%

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Switchable Polarization Beam Splitter Based on GST-on-Silicon Waveguides

Dai

et al. 2020

IEEE Photonics J.

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“…Moreover, the small switching thickness of GST (bound by the heat dissipation rate during melt-quenching to < 100 nm [182]) limits field overlap with the active O-PCM medium and further constrains the attainable phase-tuning efficiency. A new O-PCM Ge 2 Sb 2 Se 4 Te 1 (GSST) with broadband low optical loss in both phases and large switching volume has been developed to overcome these limitations [209][210][211][212][213][214][215]. As another example, the diminished optical contrast of GST in the visible spectrum has motivated the investigation of Sb 2 S 3 as an alternative O-PCM suitable for active photonics in the visible regime [216,217].…”

Section: Optical Phase-change Mediamentioning

confidence: 99%

Design for quality: reconfigurable flat optics based on active metasurfaces

et al. 2020

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Optical metasurfaces, planar subwavelength nanoantenna arrays with the singular ability to sculpt wavefront in almost arbitrary manners, are poised to become a powerful tool enabling compact and high-performance optics with novel functionalities. A particularly intriguing research direction within this field is active metasurfaces, whose optical response can be dynamically tuned postfabrication, thus allowing a plurality of applications unattainable with traditional bulk optics. Designing reconfigurable optics based on active metasurfaces is, however, presented with a unique challenge, since the optical quality of the devices must be optimized at multiple optical states. In this article, we provide a critical review on the active meta-optics design principles and algorithms that are applied across structural hierarchies ranging from single meta-atoms to full meta-optical devices. The discussed approaches are illustrated by specific examples of reconfigurable metasurfaces based on optical phase-change materials.

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“…The complex refractive index of GSST, at μm, are and for crystalline and amorphous state, respectively [18]. In most of the earlier designs [18][19][20][21] based on silicon or silicon nitride, the O-PCM is used as an overlay directly on the primary waveguide as shown in Fig. 1(a).…”

Section: Design Criteria and Modal Analysismentioning

confidence: 99%

Design of a Compact Low-Loss Phase Shifter Based on Optical Phase Change Material

Dhingra

Song

Saxena

et al. 2019

IEEE Photon. Technol. Lett.

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We propose the design of a nonvolatile, low-loss optical phase shifter based on optical phase change material (O-PCM). The optical phase change material Ge 2 Sb 2 Se 4 Te 1 (GSST), which exhibits low loss at telecommunication wavelength 1.55 µm as compared to other commonly used O-PCMs, is used in this work as the active material. Instead of direct interaction of the waveguide mode with the O-PCM, the design utilizes coupling between the primary SiN strip waveguide and a waveguide formed by O-PCM, in its amorphous state. The phase matching in the amorphous state inhibits the interaction of the waveguide mode with GSST in its highly lossy crystalline state resulting in low loss operation. Due to a high differential refractive index between the two states of GSST, the design requires a very small length of the phase shifter to accumulate the desired phase difference. The overall response of the Mach-Zehnder Interferometer (MZI) configuration using the designed phase shifter shows that the design can be used to obtain optical switching with a very small insertion loss and crosstalk over the entire C-band. Index Terms-Coupled mode analysis, Optical Switches, Phase change materials. I. INTRODUCTION hase shift for optical switching in silicon photonic devices is mainly achieved by free carrier injection [1-3] and thermo-optic effects [4]. These effects give rise to a small change in the refractive index, which results in large device length to obtain the required phase change. The alternative is to use the resonant structures to obtain devices with a small footprint, however, at the expense of low bandwidth and high sensitivity [5,6]. The compact hybrid plasmonic-photonic switches based on 3-waveguide directional couplers have also been reported, but the associated insertion loss is high [7,8]. In recent years, optical phase change materials (O-PCMs) have

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Broadband Electro-Optical Crossbar Switches Using Low-Loss Ge₂Sb₂Se₄Te₁ Phase Change Material

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Cited by 77 publications

References 31 publications

Switchable Polarization Beam Splitter Based on GST-on-Silicon Waveguides

Switchable Polarization Beam Splitter Based on GST-on-Silicon Waveguides

Design for quality: reconfigurable flat optics based on active metasurfaces

Design of a Compact Low-Loss Phase Shifter Based on Optical Phase Change Material

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