[Study on packaging-induced stress in 4 mm cavity length high-power single emitter semiconductor laser].

To reduce packaging-induced stress of long cavity length high-power single emitter semiconductor laser, the relationship between the stress and the wavelength shift was deduced on the basis of the theory that the stress can change the band gap. A method was developed for quantitatively calculating the stress by measuring the emission spectrum of the laser under pulse conditions. The results show that the soldering quality is a critical factor affecting thermal stress. The difference in stress can exceed 300 MPa due to the difference in soldering quality. By optimizing the reflowing soldering curve of the laser, the stress of the laser drops from 129.7 to 53.4 MPa. This method can also effectively solve the problem that the stress varies with storage time. This work demonstrates that the measurement and analysis of the emission spectrum of the laser can provide a useful method to study packaging stress of the high-power single emitter semiconductor laser. It is also an available means to evaluate and analyze soldering quality.

A wireless ECG monitor based on ARM / 中国医疗器械杂志

This paper presents a novel monitor which uses ARM controller AT91SAM7S64 as its main processor, LCM (Liquid Crystal Display Module) for displaying ECG waves, SD (Secure Digital memory) card for data storage and RF module PTR8000 for radio data transmission. This portable monitor boasts alarm function for abnormality and can provide dynamic ECG monitoring for patients.