In this Letter, we design and experimentally demonstrate compact mode converters with a lightning-like arrow-like polygonal subwavelength grating (SWG) structure on silicon-on-insulator (SOI) platform, which can convert the TE 0 to 1 2 modes, respectively. The footprints of proposed 0–1 0–2 are only 4.44 × 1.3 5.89 1.8 µm , experimental results show have low insertion loss (<1 dB) broad bandwidth (>50 nm). measured cross talks −7.2 dB −10.3 dB, addition, SWG advantage in fabrication,...

We proposed a new type of transverse electric (TE) polarized mode-order converter based on deeply-etched polygonal slot silicon-on-insulator waveguide. Along the direction waveguide, two irregular boundary surfaces can introduce high-contrast index modulation guided modes, leading to multimode interference in slot. Therefore, when is optimized, we achieve efficient mode conversions interference. As examples, converters from fundamental TE (TE0) first-order (TE1) and second-order (TE2) have...

In this mymargin letter, we experimentally demonstrated a 1550-nm high-power single-longitudinal-mode (SLM) distributed feedback (DFB) semiconductor laser based on sampled moiré grating (SMG). By designing the sampling structure with micrometer scale, (MG) can be equivalently realized along cavity. Then, reduce coupling coefficient near facet so as to increase output power. The cavity length and ridge width of fabricated are 1.0 mm <inline-formula...

The traveling-wave like Fabry-Perot (F-P) resonators based on transverse-mode-conversion have been extensively studied as on-chip filters. However, the incomplete transverse mode conversion will lead to coupling between two degenerated resonant modes, which brings additional loss and may further induce resonance splitting. In this paper, we take resonator with anti-symmetric nanobeam Bragg reflector an example study in both direct-coupled side-coupled resonators. coupled equations are used...

In this letter, we designed and experimentally demonstrated a compact mode converter in silicon-on-insulator (SOI) waveguide based on conformal dielectric metasurface, which uses polygonal slot structure to manipulate the wavefront of guided modes. Mode conversion from TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> can be realized within an ultracompact size (~7.66 μm) by designing...

We propose and theoretically analyze a hybrid transverse mode resonance DFB semiconductor laser which consists of one active section with π-phase shifted anti-symmetric Bragg grating (π-ASBG) two passive sections uniform grating. The light along conversion between the fundamental electric (TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ) first order xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> is formed by π-ASBG. emitted from...

We proposed a new kind of add-drop multiplexer based on π phase-shifted antisymmetric Bragg grating ( π-ASBG). Light resonance is formed in the π-ASBG with mode conversion between backward fundamental transverse electric (TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ) and forward first order (T xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> mode. With aid TE generated -ASBG, can be designed. As examples, two structures single-...

The principle, design, and characterization of a resonator on the silicon-on-insulator (SOI) platform based π phase-shifted antisymmetric Bragg grating (ASBG) are presented. With aid an asymmetric directional coupler (ADC), resonance circuit between two ASBGs is formed by forward first-order transverse electric (TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> ) mode backward fundamental...

An anti-symmetrically sampled Bragg grating (ASBG) with single mode waveguide is proposed and investigated for the first time. Based on anti-symmetric periodic structure, coupling coefficient between forward backward guided modes becomes zero, thus nearly no light reflected. Besides, equivalent tilted effect radiation found. If another sampling structure imposed to form a grating, 0th sub-grating can be avoided, while ± 1st sub-gratings are adjusted as uniform gratings normal performances....

In this paper, we present the finding that periodic structural defects (PSDs) along a Bragg grating can shift wavelength. This effect is theoretically analyzed and confirmed by numerical calculation. We find wavelength determined defect size period of defects. The be well tuned properly designing PSDs, may provide an alternative method to fabricate grating-based multiwavelength devices, including optical filter arrays laser arrays. regards precision, proposed has advantage over traditional...

The clinical findings frequently presented in trisomy 4q syndrome including mental retardation, developmental delay and multiple abnormalities such as microcephaly, acrocephaly, well malformed ears, high/broad/depressed nasal bridge, teeth thumb anomalies. It has been proposed that is caused by a familial balanced translocation or de novo imbalance. We reported new case of with karyotype 46, XY, der(5)t(4;5)(q27;q35) this karyotye was for the first time. His phenotype included severe growth...

This paper proposes a tunable multiple-passband microwave photonic filter (MPF) that is incorporated with an injection-locked Fabry-Pérot (FP) laser.In the proposed MPF, multiple passbands can be easily generated based on frequency-selection effects of laser structure in case light waves injection.The novelty here obtained MPF achieve either dual-passband or single-passband by using merely one experimental scheme.Moreover, since injection ratio scheme high, central frequency each passband...

In this letter, we provided a proof-of-concept study on the anti-symmetric sampled Bragg grating (ASBG) with π equivalent phase shift (π-EPS) in silicon-on-insulator (SOI). A four-channel narrow-band passive filter array was fabricated. Experimental results show that 0th-order resonance is totally eliminated, while +1st-order maintained. addition, 3-D finite-difference-time-domain (3-D-FDTD) algorithm also used to analyze other characteristics of structure, such as radiation phenomenon...

We propose two types of structures to achieve the control Fano and electromagnetically induced transparency (EIT) line shapes, in which dual one-dimensional (1D) photonic crystal nanobeam cavities (PCNCs) are side-coupled a bus waveguide with different gaps. For proposed type Ⅰ Ⅱ systems, phase differences between periodic π 0, respectively. The whole theoretically analyzed via coupled mode theory numerically demonstrated using three-dimensional finite-difference time-domain (3D FDTD)...

Objective: To explore changes in the alpha rhythm wavelength of background electroencephalography Alzheimer’s disease patients with different degrees dementia a resting state; examine their correlation degree cognitive impairment; determine whether can distinguish mild patients, moderately severe and healthy controls at individual level; identify cut-off value to differentiate from controls. Methods: Quantitative signals 42 disease, 40 during rest state eyes closed were analyzed using...

Tilted Bragg grating (TBG) has been intensively investigated for photonic devices such as fiber sensors and on-chip filters. In this article, we present that TBG can be equivalently realized by designing the tilted sampled (TSBG). As its basic is uniform sampling structure in order of micrometer, fabrication TSBG with one step holographic exposure combined micro-lithography. examples, designed simulated equivalent light responses TSBGs multimode planar waveguide single-mode respectively....

Tilted Bragg grating (TBG) has been intensively investigated for photonic devices such as fiber sensors and on-chip filters. In this paper, we present that TBG can be equivalently realized by designing tilted sampled (TSBG), which is formed superimposing the pre-designed sampling structure on basic grating. Since uniform in order of micrometer, fabrication TSBG with one step holographic exposure combined another micro-lithography. We designed simulated equivalent light responses TSBGs target...