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The Society of Photo-Optical Instrumentation Engineers (SPIE), Nanophotonics X 2024 -- 7 April 2024 through 12 April 2024 -- 200395, Bragg-Grating-Waveguide (BGW) delay lines are commonly used in transmission mode, owing to the significant elevation in group index observed at the edge of the stopband. However, achieving delays often necessitates structures with a larger footprint, such as cascaded or spiral designs, which consume a substantial amount of chip estate. Recent approaches to optimize chip space involve round-trip configurations with reflectors, but these can restrict bandwidth and cause mode conversion. Our study introduces an efficient solution: a meta-reflector for TE0 mode, enabling double delays via a single path, while also employing a step taper in TM0 mode to couple the TM signal into a strip waveguide, within a 1.9 × 2.6 µm2 area. Simulations show that in TE mode, there is a peak attenuation of -0.18 dB within the 1530–1590 nm wavelength spectrum, and in TM mode, the loss reaches -4.73 dB across the 1500–1600 nm band. In the computation of losses, the customary impact of the Bragg grating waveguide was disregarded, with attention concentrated exclusively on the design of the reflector. © 2024 SPIE., 2210A, 122E566

The Society of Photo-Optical Instrumentation Engineers (SPIE), Nanophotonics X 2024 -- 7 April 2024 through 12 April 2024 -- 200395, Integrated optical phased arrays (OPAs) are important for various applications such as LIDAR, microscopy, wireless communication, and holography. Traditional one-dimensional N-element OPAs with individual phase shifters for varied steering angles often have emitter spacings that exceed half a wavelength, leading to grating lobes. Moreover, using true-time-delay lines with varied numbers of periods for different delays may cause amplitude inconsistencies and further side lobe elevation. The proposed partially apodised (PA) one-dimensional grating waveguide design controls amplitude while conserving the time delay for targeted steering angles, using distributions as Uniform to minimize grating and side lobes. We fabricated a four-element array with insertion losses of -3 dB for the PA version across the 1530-1580 nm wavelength band. © 2024 SPIE., 2210A, 122E566

The Society of Photo-Optical Instrumentation Engineers (SPIE), The challenge of designing crossings in one-dimensional grating waveguides (1DGWs) arises from the noticeable asymmetry in Bloch mode profiles, which causes the guided modes to be compressed toward the outer sidewall. The proposed solution involves using digitized metamaterials in an extensively corrugated 1DGW on a silicon-on-insulator platform. The resulting crossing structure has an ultra-miniaturized and ultra-low loss design, with a broad bandwidth spanning from 1500 to 1580 nm, while maintaining a minimal footprint of merely 2.1×2.1 µm2. The fabricated device is found to have an insertion loss of -2.52 dB within the wavelength range of 1500 to 1580 nm. This design represents a significant advancement in the pursuit of compact and low-energy silicon photonic waveguide crossings. © 2024 SPIE., Scientific and Technical Research Council; TUBITAK, (2210A, 122E566)

The Society of Photo-Optical Instrumentation Engineers (SPIE), Integrated Photonics Platforms III 2024 -- 7 April 2024 through 10 April 2024 -- Strasbourg - -201263, Devices engineered for slowing light, utilizing one-dimensional grating waveguides and fabricated from silicon nitride, often necessitate large footprints to secure the required delay, a consequence of the material’s inherently low refractive index. Our approach employs a genetic algorithm to optimize 100×100nm̂2 etchings on a predetermined grating waveguide topology, allowing for either the selective guidance of peak pulse intensity of the output or the augmentation of true time delay within the identical unit length. Within the chosen predetermined topology, the optimal configuration was identified based on the properties of the signal excitation in the time domain. This approach significantly facilitates the application-specific selection of peak intensity decay rate and time delay behavior within a 1D grating waveguide system. © 2024 SPIE., Scientific and Technical Research Council; TUBITAK, (2210A, 122E566)