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In this article, we report the first experimental results of a novel 4H-silicon carbide (SiC) p-i-n photodetector based on a vertical nanocone array (NCA). It is fabricated by electron beam lithography and inductively coupled plasma (ICP) etching technology. The performance of static and dynamic behavior was studied systematically. It shows the responsivity of ~41.9 mA/W under 360 nm at a bias voltage of -0.5 V and has a linear response to the ultraviolet (UV) light in a wide light intensity range of 0.1-10⁴ mW/cm². The response time decreased as the light intensity rose from 3 mW/cm² to 5 W/cm² and then leveled off at higher light intensity (>100 mW/cm²), which is about 0.25 ms. The photodetector -3-dB cutoff is ~3400 Hz at λ = 360 nm and light intensity = 100 mW/cm². Besides, the detector can respond to the UV light from 260 to 360 nm and the peak responsivity is ~78 mA/W at 320 nm. The analysis results have reference values for the development of an innovative 4H-SiC UV photodetector to some extent.

For design of automotive airbag electronic control units (AB ECU), it is essential to have a validated and reliable finite element (FE) simulation model in place in order to allow already in an early design stage for the accurate prediction of the ECU’s structural vibration behavior. A “bottom-up” approach which described in the ASME guide for verification and validation (ASME V&V 10-2006) is applied for the validation of the AB ECU simulation model. The AB ECU is decomposed into different assembly level. Single printed circuit board (PCB) is the lowest elementary component level. In the PCB level simulation and validation, the influence of in-plane pre-stress on PCB’s transverse vibration characteristic has been encountered, but it has been found out that the source of the in-plane pre-stress can not be explained by classical beam/plate theory. Analysis and simulation for PCB fixation reveals that the fundamental source of the in-plane pre-stress is structure’s geometric nonlinearity.

In this paper, using Free coordinate system and the Jones vector to analyse the discipline of polarization state when the light penetrates the confocal system, so obtains the distribution of the polarization state when a line polarized light penetrates the confocal system. Using the method of tracing ray obtains the distribution of the polarization state on the image surface when light penetrates the Pehan prisms system and the Telescope system with Pehan prisms-There are both elliptical polarized lights when light passes two roof planes of the Pehan prisms system and the telescope system with Pehan prisms respectively, of which the difference value between the azimuth angle and ellipticity angle is betweet ± 1° on the supposition from the same roof planes. Do the experiment analysis using Stokes parameter measurement, then gets consistent result with theory. At last, clears the Polarization aberration effect of Telescope system with Pehan prisms results from the Pehan prisms.

Using the law of refraction and reflection of vector form to trace the light direction of propagation in the Smith prism. Be based on it, get the reflection phase shifter δs and δp on every planes, consequently obtain virtue matrix using Jones vector. The distribution of the polarization state of emergent light wave from Smith prism is analyzed when the light is vertical incidence and different azimuth, homochromatism and linearly polarized. The polarization aberration feature of Smith prism is obtained. At last,the detection experiment is done using the Stokes parameter measurement, and gets the consistent result with theory. The text lay the foundation for studying polarization aberration that effects on imaging quality and detection and correction of polarization aberration.

A kind of Laser source with ATC, APC,ACC and modulation interface is introduced, we use the sine electric signal to complete direct modulation, the sine electric signal‘s frequency change from 50 MHz to 200 MHz,and the period is 0.5ms,then we use New focus 1161Photodetector which frequency response is 1 GHz to detect the output modulated light signal, the modulated light signal‘s frequency change from 50 MHz to 200 MHz, contrast with the electric signal, analyzing the factors which influence the light signal‘s modulation depth, through adjusting laser‘s output power and electric signal‘s peak, the light signal‘s modulation depth can reach 33% at last. Click here and insert your abstract text.