Coupling loss
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Ultralow transmission loss in inhibited-coupling guiding hollow fibers Open
Attenuation in photonic bandgap guiding hollow-core photonic crystal fiber (HC-PCF) has not beaten the fundamental silica Rayleigh scattering limit (SRSL) of conventional step-index fibers due to strong core-cladding optical overlap, surfa…
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High-efficient coupler for thin-film lithium niobate waveguide devices Open
Lithium niobate (LN) devices have been widely used in optical communication and nonlinear optics due to its attractive optical properties. The emergence of the thin-film lithium niobate on insulator (LNOI) improves performances of LN-based…
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Fiber-chip edge coupler with large mode size for silicon photonic wire waveguides Open
Fiber-chip edge couplers are extensively used in integrated optics for coupling of light between planar waveguide circuits and optical fibers. In this work, we report on a new fiber-chip edge coupler concept with large mode size for silico…
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High-extinction-ratio silicon polarization beam splitter with tolerance to waveguide width and coupling length variations Open
We demonstrate a compact silicon polarization beam splitter (PBS) based on grating-assisted contradirectional couplers (GACCs). Over 30-dB extinction ratios and less than 1-dB insertion losses are achieved for both polarizations. The propo…
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Low-loss single-mode hollow-core fiber with anisotropic anti-resonant elements Open
A hollow-core fiber using anisotropic anti-resonant tubes in the cladding is proposed for low loss and effectively single-mode guidance. We show that the loss performance and higher-order mode suppression is significantly improved by using…
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Low-loss fiber-to-chip couplers with ultrawide optical bandwidth Open
Providing efficient access from optical fibers to on-chip photonic systems is a key challenge for integrated optics. In general, current solutions allow either narrowband out-of-plane-coupling to a large number of devices or broadband edge…
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Aluminum nitride-on-sapphire platform for integrated high-Q microresonators Open
We demonstrate aluminum nitride (AlN) on sapphire as a novel platform for integrated optics. High-confinement AlN microring resonators are realized by adopting a partially etched (pedestal) waveguide to relax the required etching selectivi…
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Flip-chip integration of tilted VCSELs onto a silicon photonic integrated circuit Open
In this article we describe a cost-effective approach for hybrid laser integration, in which vertical cavity surface emitting lasers (VCSELs) are passively-aligned and flip-chip bonded to a Si photonic integrated circuit (PIC), with a tilt…
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Low-loss fiber grating coupler on thin film lithium niobate platform Open
A grating coupler with a high coupling efficiency and low back reflections is designed and demonstrated on the thin film lithium niobate platform, which facilitates an efficient interface between a lithium niobate ridge waveguide and a sta…
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2-D Grating Couplers for Vertical Fiber Coupling in Two Polarizations Open
We demonstrate highly efficient couplers in a two-dimensional grating configuration for a vertical fiber-coupling fabricated in the silicon-on-insulator platform. A combination of sub-wavelength reflectors and blazed gratings enables both …
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Ultra-compact low-loss broadband waveguide taper in silicon-on-insulator Open
A novel design of large bandwidth, fabrication tolerant, CMOS-compatible compact tapers (15 um) have been proposed and experimentally demonstrated in silicon-on-insulator. The proposed taper along with linear grating couplers for spot-size…
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Grating coupler on lithium niobate thin film waveguide with a metal bottom reflector Open
To improve the coupling efficiency between a single-mode fiber and the waveguide on lithium niobate thin film (LNOI), a fiber-to-chip grating coupler with a metal bottom reflector was designed, fabricated, and characterized. A maximum coup…
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AC loss and contact resistance in REBCO CORC<sup>®</sup>, Roebel, and stacked tape cables Open
Many high-temperature superconductor (HTS) applications require superconducting cables with high currents while operating in an alternating magnetic field. HTS cables should be composed of numerous superconducting tapes to achieve the requ…
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Printed freeform lens arrays on multi-core fibers for highly efficient coupling in astrophotonic systems Open
Coupling of light into multi-core fibers (MCF) for spatially resolved spectroscopy is of great importance to astronomical instrumentation. To achieve high coupling efficiencies along with fill-fractions close to unity, micro-optical elemen…
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Efficient light coupling between an ultra-low loss lithium niobate waveguide and an adiabatically tapered single mode optical fiber Open
A lithium niobate on an insulator ridge waveguide allows constructing high-density photonic integrated circuits thanks to its small bending radius offered by the high index contrast. Meanwhile, the significant mode-field mismatch between a…
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Circular core single-mode polymer optical waveguide fabricated using the Mosquito method with low loss at 1310/1550 nm Open
We fabricate low-loss single-mode (SM) polymer optical waveguides using a photomask-free simple technique named the Mosquito method. The insertion losses of a 5-cm long SM polymer waveguide fabricated are 2.52 dB and 4.03 dB at 1310- and 1…
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Particle swarm optimization of silicon photonic crystal waveguide transition Open
Slow light generated through silicon (Si) photonic crystal waveguides (PCWs) is useful for improving the performance of Si photonic devices. However, the accumulation of coupling loss between a PCW and Si optical wiring waveguides is a pro…
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Low-loss waveguides on Y-cut thin film lithium niobate: towards acousto-optic applications Open
We investigate the dependence of photonic waveguide propagation loss on the thickness of the buried oxide layer in Y-cut lithium niobate on insulator substrate to identify trade-offs between optical losses and electromechanical coupling of…
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Grating Coupler for an On-Chip Lithium Niobate Ridge Waveguide Open
We report simulation and fabrication of a grating coupler for coupling of light between an on-chip lithium niobate ridge waveguide and an optical fiber. A grating coupler with an insertion loss of less than 10 dB for C-band frequencies (15…
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Membrane distributed-reflector laser integrated with SiOx-based spot-size converter on Si substrate Open
We demonstrate monolithic integration of a 50-μm-long-cavity membrane distributed-reflector laser with a spot-size converter, consisting of a tapered InP wire waveguide and an SiOx waveguide, on SiO2/Si substrate. The device exhibits 9.4-G…
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Two-dimensional grating coupler on silicon with a high coupling efficiency and a low polarization-dependent loss Open
Two-dimensional grating couplers are important components for silicon photonic circuits to achieve light coupling from/to a fiber for both polarizations. A two-dimensional grating coupler structure with a high coupling efficiency and a low…
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Fabricated Optical Strip Waveguide of Nanophotonics Lithium Niobate Open
The fabrication of an optical waveguide by designing the device and using a positive photoresist via photo lithography (ultraviolet light) to transfer the pattern of the sample has been studied. A direct coupler method was used to investig…
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Low connector-to-connector loss through silicon photonic chips using ultra-low loss splicing of SMF-28 to high numerical aperture fibers Open
Here we present extremely low connector-to-connector loss (≤3 dB) through silicon photonic chips using ultra-low loss (≤0.15 dB) splicing between SMF-28 and ultra-high numerical aperture (UHNA) fibers. The small MFD from the UHNA fibers en…
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High-Efficiency Ultra-Broadband Multi-Tip Edge Couplers for Integration of Distributed Feedback Laser With Silicon-on-Insulator Waveguide Open
A high-efficiency ultra-broadband multi-tip edge coupler based on a silicon-on-insulator platform for direct coupling with the elliptic beam of a distributed feedback laser was developed. The device is composed of a multi-tip section and a…
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Metal based grating coupler on a thin-film lithium niobate waveguide Open
Thin-film lithium niobate (LN) has been proved to be an excellent platform for building compact active and nonlinear photonic components on a chip. The coupling of a sub-micron sized LN waveguide and a single-mode fiber remains as one chal…
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Fiber-to-chip fusion splicing for low-loss photonic packaging Open
Silicon photonic devices are poised to enter high-volume markets such as data communications, telecommunications, biological sensing, and optical phased arrays. Permanently attaching a fiber to the photonic chip with high optical efficienc…
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AC loss and contact resistance in highly flexible rebco cable for fusion applications Open
High Temperature Superconductor (HTS) materials can operate at higher magnetic fields up to 20 T with high critical current and higher operating temperature, compared to low temperature superconductors (LTS). A Highly Flexible REBCO Cable …
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Polarization-independent one-dimensional grating coupler design on hybrid silicon/LNOI platform Open
We report here on one-dimensional (1D) grating couplers based on hybrid silicon/LNOI platform for polarization-independent and high-efficient single-polarization coupling efficiencies. A low index oxide buffer layer was introduced in betwe…
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Roughness Estimation of Multimode Rectangular Optical Waveguide Based on the Scattering Loss Difference Between SMFW and MMFW Structures Open
Based on the scattering loss difference between the single-mode-fiber-optical-waveguide (SMFW) and multimode-fiber-optical-waveguide (MMFW) structures, a method to estimate the roughness of multimode rectangular optical waveguide (ROW) is …
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Compact and Broadband Edge Coupler Based on Multi-Stage Silicon Nitride Tapers Open
We have proposed and experimentally realized an ultra-compact and broadband silicon nitride edge-coupler that enables high coupling efficiency. The proposed coupler was realized by concatenating short tapers in four stages, whose angles we…