We report on the room-temperature cascade laser （QCL） at λ -4.7μm. cw operation of a surface grating Both grating design and material distributed feedback （DFB） quantum optimization are used to decrease the thre...We report on the room-temperature cascade laser （QCL） at λ -4.7μm. cw operation of a surface grating Both grating design and material distributed feedback （DFB） quantum optimization are used to decrease the threshold current density and to increase the output power. For a high-reflectivity-coated 13-μm-wide and 4- mm-long laser, high wall-plug efficiency of 6% is obtained at 20℃ from a single facet producing over I W of ew output power. The threshold current density of DFB QCL is as low as 1.13kA/cm^2 at 10℃ and 1.34kA/cm2 at 30℃ in cw mode. Stable single-mode emission with a side-mode suppression ratio of about 30 dB is observed in tile working temperature range of 20-50℃.展开更多
提出并设计了一种新型RC振荡器,采用3.3 V CMOS工艺实现。与传统的基于外部迟滞比较器的原理不同,该RC振荡器巧妙地基于内部正反馈的迟滞比较器设计而成。它具有电路结构简单,芯片面积小,成本低廉的优点,而且可以根据不同的控制信号,工...提出并设计了一种新型RC振荡器,采用3.3 V CMOS工艺实现。与传统的基于外部迟滞比较器的原理不同,该RC振荡器巧妙地基于内部正反馈的迟滞比较器设计而成。它具有电路结构简单,芯片面积小,成本低廉的优点,而且可以根据不同的控制信号,工作于高频2.5 MHz或低频135 kHz。仿真结果表明,该电路符合设计指标。展开更多
基金Supported by the National Basic Research Program of China under Grant Nos 2013CB632801 and 2013CB632803the National Natural Science Foundation of China under Grant Nos 61435014,61306058 and 61274094the Beijing Natural Science Foundation under Grant No 4144086
文摘We report on the room-temperature cascade laser （QCL） at λ -4.7μm. cw operation of a surface grating Both grating design and material distributed feedback （DFB） quantum optimization are used to decrease the threshold current density and to increase the output power. For a high-reflectivity-coated 13-μm-wide and 4- mm-long laser, high wall-plug efficiency of 6% is obtained at 20℃ from a single facet producing over I W of ew output power. The threshold current density of DFB QCL is as low as 1.13kA/cm^2 at 10℃ and 1.34kA/cm2 at 30℃ in cw mode. Stable single-mode emission with a side-mode suppression ratio of about 30 dB is observed in tile working temperature range of 20-50℃.
文摘提出并设计了一种新型RC振荡器,采用3.3 V CMOS工艺实现。与传统的基于外部迟滞比较器的原理不同,该RC振荡器巧妙地基于内部正反馈的迟滞比较器设计而成。它具有电路结构简单,芯片面积小,成本低廉的优点,而且可以根据不同的控制信号,工作于高频2.5 MHz或低频135 kHz。仿真结果表明,该电路符合设计指标。
