Single mode operation of impurity-induced disordering large area vertical cavity surface emitting lasers

Vertical-cavity surface-emitting lasers (VCSELs) with suitable interdiffusion quantum wells profile by the use of selective impurity-induced disordering is proposed for high power single mode operation in large area devices. It is shown that the transverse optical confinement in the quantum well active region formed by the diffusion profile counteracts the influence of carrier spatial hole burning for VCSELs biased at high injection current. Results indicate that a single mode operation can be maintained in VCSELs with the diameter of core region equal to 50µm.published_or_final_versio

Fabry Perot semiconductor lasers with periodic diffused quantum wells structure

Fabry Perot semiconductor laser with periodic change in the extent of interdiffusion along the longitudinal direction of the quantum well active region is proposed to improve the discrimination between cavity modes.published_or_final_versio

Why do battered women abuse their children? Explore and discussion

Congress Theme: New Directions in Child Protection and WellbeingOBJECTIVES: A strong association between the occurrences of imitate partner violence and child abuse is confirmed in studies. This study therefore aims to explore the associated factors of battered women being violent towards their children and its implication on the service development for the family at risk. The different characteristics among abused women without and with children at different ages will be examined. This study can enrich knowledge on child protection, especially in families with multiple types ...postprin

High-power single-mode operation in DFB and FP lasers using diffused quantum-well structure

Distributed feedback (DFB) and Fabry-Perot (FP) semiconductor lasers with step and periodic interdiffusion quantum-well structures are proposed for high-power single-longitudinal-mode operation. It is shown that the phase-adjustment region formed by the diffusion step (i.e., step change in optical gain and refractive index) counteracts the influence of spatial hole burning, especially for DFB lasers with large coupling-length products biased at high injection current. Furthermore, it is found that with careful design of the diffusion grating (i.e., grating period and amount of diffusion extent) of FP lasers, side-mode suppression ratio can be enhanced and threshold current density can be minimized to a satisfied level.published_or_final_versio

Performance study of an ultrasonic transducer used for wire bonding

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Vertical-cavity surface-emitting semiconductor lasers with diffusedquantum wells

A self-consistent dynamic model is developed including the current distribution, carrier diffusion rate and spatial hole burning effects to investigate the modulation response of vertical-cavity surface-emitting lasers with diffused quantum wells structure. It is found that the overall performance including relaxation oscillation frequency and modulation bandwidth is improved.published_or_final_versio

The Origin of Meridians

This article explores the origin of meridians. It suggests that the origin of meridians is closely related to the imageries derived by ancient physicians experiencing the circulation of Qi in their bodies during Qigong practice. Based on the cognitive experience from Qigong practice, as well as the symbolic analogy of the flow of rivers and the irrigation system of agriculture, the meridian theory has constructed a model of Qi and blood circulation. Such model is abstract and yet concrete, dialectic and yet intuitive, definite and yet vague, integrated and yet independent, having profound influence on the overall formation of traditional Chinese medicine theories.published_or_final_versio

Sensors for automatic process control of wire bonding

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Dynamics of an ultrasonic transducer used for wire bonding

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Elimination of hysteresis effect in superparamagnetic nanoparticle detection by GMR sensors for biosensing

The biosensing methods utilizing superparamagnetic nanoparticles as bio-tags and giant magneto-resistive (GMR) or tunneling magnetoresistive (TMR) sensors as signal detectors have attracted increasing interests in early disease diagnosis as well as in molecular biology research area. [1] To achieve the signal of targets, one commonly used method is to compare the sensor hysteresis loops before and after the introducing of superparamagnetic nanoparticles onto sensor surface, and the sensor response variation has been regarded as an indicator of target analyte's amount. [2, 3] However, the hysteresis effect existing in ferromagnetic material may bring an error in the sensor output reading, which can be problematic in the superparamagnetic nanoparticle signal detection. Since the hysteresis behavior exists in all magnetoresistive sensors made of ferromagnetic material, it is necessary to investigate its effect on superparamagnetic nanoparticle detection and eliminate its negative influences. © 2015 IEEE.postprin