- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Discerning Localized Thermal Heating from Mechanical Strain Using an Embedded Distributed Optical Fiber Sensor Network
摘要： Prior research has demonstrated that distributed optical fiber sensors (DOFS) based on Rayleigh scattering can be embedded in carbon fiber/epoxy composite structures to rapidly detect temperature changes approaching 1000°C, such as would be experienced during a high energy laser strike. However, composite structures often experience mechanical strains that are also detected during DOFS interrogation. Hence, the combined temperature and strain response in the composite can interfere with rapid detection and measurement of a localized thermal impulse. In this research, initial testing has demonstrated the simultaneous response of the DOFS to both temperature and strain. An embedded DOFS network was designed and used to isolate and measure a localized thermal response of a carbon fiber/epoxy composite to a low energy laser strike under cyclic bending strain. The sensor interrogation scheme uses a simple signal processing technique to enhance the thermal response, while mitigating the strain response due to bending. While our ultimate goal is rapid detection of directed energy on the surface of the composite, the technique could be generalized to structural health monitoring of temperature sensitive components or smart structures.
关键词： smart structures,distributed optical fiber sensors,temperature sensors,structural health monitoring,high energy radiation,polymer matrix composites,strain sensors,strain compensation
更新于2025-09-23 15:21:01
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AlInGaN-based superlattice p-region for improvement of performance of deep UV LEDs
摘要： A deep ultraviolet light-emitting diode (DUV LED) consisting of a specifically designed intermediate p-type region involving a superlattice quaternary nitride alloy has been proposed. The light output power of the proposed structure has been found significantly large; around 28.30 times high in comparison to the conventional structure, at the current density of 200 A/cm2. The maximum internal quantum efficiency of the proposed structure is 153.63% higher compared to the conventional one. Moreover, the efficiency droop has been reduced by 99.08%. Absence of abrupt potential barrier owing to the strain compensation provided by the superlattice p-AlInGaN layer offers an attractive solution for enhancing the hole injection into the active region leading to the improvement in performance of DUV LED.
关键词： Efficiency droop,Superlattice-AlInGaN,Strain compensation,DUV LED
更新于2025-09-23 15:21:01
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High Power Quantum Cascade Laser at λ 5.1 <i>μ</i> m Based on Low Strain Compensation Design
摘要： We demonstrate the development of a high performance quantum cascade laser at (cid:2) ～ 5(cid:3)1 (cid:4)m with low strain-balanced structure using a double-phonon resonant design approach. The wafer was grown by solid source molecular beam epitaxy and fabricated with buried heterostructure waveguides. A high output power up to 1.5 W is obtained at 288 K with a high wall plug ef?ciency of 8.5% for devices with stripe dimension of 5 mm × 10 (cid:4)m. The characteristic temperatures, T 1, are 114 K and 198 K respectively.
关键词： High Power Laser,Strain-Compensation,Quantum Cascade Laser
更新于2025-09-12 10:27:22