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Abstract The social media platform and the information dissemination revolution have changed the thinking, needs, and methods of students, bringing development opportunities and challenges to higher education. This paper introduces social media into the classroom and uses quantitative analysis to investigate the relation between design college students’ learning self-efficacy and social media for design students, aiming to determine the effectiveness of social media platforms on self-efficacy. This study is conducted on university students in design media courses and is quasi-experimental, using a randomized pre-test and post-test control group design. The study participants are 73 second-year design undergraduates. Independent samples t-tests showed that the network interaction factors of social media had a significant impact on college students learning self-efficacy. The use of social media has a significant positive predictive effect on all dimensions of learning self-efficacy. Our analysis suggests that using the advantages and value of online social platforms, weakening the disadvantages of the network, scientifically using online learning resources, and combining traditional classrooms with the Internet can improve students' learning self-efficacy.

We demonstrate compact optically pumped microsquare cavity laser on InP-based multiple-quantum-wells material platform. Continuous-wave operation is achieved for microsquare cavity with footprint as small as 4 × 4 μm2. Numerical mode analysis and experimental characterization of the microsquare laser are conducted, and the results are compared with the commonly used microdisk cavity laser fabricated on the same platform. The microsquare laser shows a lower lasing threshold and infers a higher differential efficiency than the microdisk counterpart. The microsquare cavity laser has also sufficiently high quality factor, and higher pumping injection efficiency due to the more evenly distributed field profile as compared to that of the microdisk. Experimental result also shows that the microsquare laser has better temperature stability than the microdisk. These results promise a potential alternative laser structure for on-chip light source applications. [ABSTRACT FROM PUBLISHER]

The authors report the first realization of sub-200 nm wide AlN-GaN-AlN (AGA) ridge waveguide with height-to-width ratio of ~6:1, fabricated via inductively coupled plasma (ICP) etching with Cl2/Ar gas chemistry. Reactive ion etching (RIE) power and ICP power were varied in the ranges of 100-450W and 200-600 W, respectively. An optimized RIE power and ICP power at 100 and 400 W, respectively, reduced the density of nanorods formed in the etched trenches. Further optimization of the gas flow rate of Cl2/Ar to 40/10 sccm improved the slope of the etched waveguide. In addition, the authors also developed a simple and novel dice-and-cleave technique to achieve cleaved end facet of AGA waveguide. [ABSTRACT FROM AUTHOR]

As the basic building block for photonic device integration, silicon nanophotonic waveguide requires low-loss propagation for high-performance ultra-compact photonic device. We experimentally study silicon dioxide hard masks grown by two different methods, i.e., thermal oxidation and plasma-enhanced chemical vapor deposition (PECVD) for silicon nano-waveguides fabrication and their effects on the propagation loss. It is found that the denser and smoother quality of thermally grown silicon dioxide increases the etch selectivity against silicon and reduces the line edge roughness transferred to the silicon nano-waveguide sidewalls, hence resulting in a lower loss as compared with the PECVD silicon dioxide hard mask. With thermally grown silicon dioxide as a hard mask, the silicon nano-waveguides loss can be halved for a 650-nm-wide nano-waveguide, and the loss is comparable with a waveguide fabricated with a resist etch mask. [ABSTRACT FROM PUBLISHER]

Facet reflections at the waveguide-air interface for strongly-guiding waveguides with sub-wavelength scale dimensions do not follow the usual Snell's law. Significant amount of reflected power can be channeled into higher order modes as well as radiation modes. This paper shows for the first time how the exact analytical solution of the facet reflection can be obtained by using a new technique based on Fourier analysis and perturbative series summation without the need for approximation or iteration. The proposed analysis enables the distribution of power reflected into various guided and radiation modes to be readily computed. Through this technique, a spectral overlapping criterion and a coupling matrix are derived that analyze effectively the power distribution among all the strongly and weakly-coupled radiation modes in an end-facet reflection. Accurate pre-determination of the number of radiation modes for efficient computation without compromising resultant accuracy is achieved. More importantly, the anomalous wave reflection behaviors at the facet of a strongly-guiding waveguide are presented. These include anomalous high radiation modes coupling as a function of cladding refractive index not reported before. This paper further includes an exemplary illustration of the analysis based on a symmetric planar nano-waveguide with high refractive index contrast for both TE and TM polarization under fundamental incident mode. [ABSTRACT FROM PUBLISHER]

We have investigated numerically and experimentally a fiber Bragg grating (FBG) sensor interrogation scheme utilizing a linear chirped grating-based Sagnac loop as a wavelength-dependent receiver. The scheme is suitable for both static and dynamic sensor interrogation with advantages of stable and linear readout response and easily-adjustable sensing resolution and dynamic range. Static and dynamic strain resolutions as high as ± 4.2 με and 0.406 με/√ Hz have been demonstrated using this scheme. [ABSTRACT FROM PUBLISHER]

To overcome shortcomings of the ex situapproaches, in situdetection using H2O2molecules to diagnose ischemia through enhanced protein direct electron transfer on a unique horseradish peroxidase–Au nanoparticles–polyaniline nanowires biofilm is demonstrated and it is discovered that the extracellular H2O2molecule released per ischemic cell is 2.7-times of that of a normal cell. [ABSTRACT FROM AUTHOR]

A bidirectional nonreciprocal wavelength-interleaving filter based on an optically coherent high birefringence fiber transversal filter structure is demonstrated. Stable, low loss, low dispersion, and high isolation operation is demonstrated with reconfigurable transfer characteristics for interleaved channel spacing of 0.8 nm. [ABSTRACT FROM PUBLISHER]

A simple technique for direct real-time assessment of a fiber laser cavity-mode condition during operation is demonstrated. Mode stabilization and optimization with this cavity-mode monitoring and conditioning feedback scheme shows significant improvements to the output performance. [ABSTRACT FROM PUBLISHER]

By integrating a fibre polarisation scrambler with the modified phase shift modulation technique, differential group delay characterisation is demonstrated with high wavelength and delay resolution, and enhanced measurement immunity to environmental perturbation. [ABSTRACT FROM AUTHOR]