Coupling tolerances of high-index silicon-oxynitride waveguides with small bending radii

Fadel, Maxim; Gentemann, Roland B.

doi:10.1016/j.aeue.2006.12.007

Cited by 4 publications

(1 citation statement)

References 3 publications

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“…Fadel et al. [ 67 ] studied the impact of non‐zero end separation in the coupling of UHNA‐3 fibers to waveguides, finding an end‐separation of 1 µm leads to a 0.4 dB coupling loss per facet. A 1 µm separation can result from a cleave angle error from perpendicular in the wafer plane of less than 1 degree for a 125 µm cladding diameter, this level of tolerance being rather difficult to achieve with hand cleaving and wafer alignment in the lithography tools.…”

Section: Characterization Of the Hybrid As2s3–ge:sio2 Waveguidementioning

confidence: 99%

Hybrid Chalcogenide‐Germanosilicate Waveguides for High Performance Stimulated Brillouin Scattering Applications

Lai

Choi

Athanasios

et al. 2021

Adv Funct Materials

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On‐chip stimulated Brillouin scattering (SBS) in arsenic trisulfide (As2S3) planar waveguides lead to a range of outstanding demonstrations in microwave photonics signal generation and processing. However, the lack of other integrated functionalities, high back reflections, and large in‐ and out‐fiber coupling losses in high index contrast waveguides cause a number of serious impairments and lessen the applicability of microwave photonic devices. In this report, a hybrid integration scheme is demonstrated where As2S3 waveguides optimized for SBS gain are coupled with very low losses via a vertical taper to a high index contrast and versatile germanosilicate (Ge:SiO2) platform. The Ge:SiO2 waveguide is optimally mode‐matched to commercially available high numerical aperture optical fiber to achieve very low coupling losses. The structure has very low back reflection due to the adiabatic nature of the taper and negligible refractive index difference across the fiber‐chip interface. The hybrid architecture exhibits a similar Brillouin gain coefficient to its monolithic counterpart but with an improvement of >3 dB/facet fiber‐to‐chip loss and >20 dB reduction in facet reflectivity. The hybrid structures demonstrated will bring chalcogenide‐based chip scale SBS devices closer to practical application.

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Section: Characterization Of the Hybrid As2s3–ge:sio2 Waveguidementioning

confidence: 99%