中国电子科技集团公司 第二十四研究所, 重庆 400060
在0.35 μm标准CMOS工艺下实现了一款采用低阈值技术的高速流水线模数转换器。该转换器包括采样保持电路、流水线ADC核、时钟电路和基准电路。相比于传统电路, 该模数转换器中采样保持电路的放大器采用了低阈值设计技术。其优势在于, 在特定工艺下, 通过低阈值器件补偿放大器可实现高增益带宽, 提高了模数转换器的速度。同时, 设计了一种全新的保护电路, 可有效保证电路的正常工作。采用一种独特的偏置电路设计技术, 不仅能够优化跨导放大器的增益和带宽, 还可以调节MOS器件工作状态。转换器采用4 bit+8×15 bit+3 bit的十级流水线架构, 实现了14位精度的模数转换功能。在5 V电源100 MHz时钟下, 仿真结果表明, SINAD为74.76 dB, SFDR为87.63 dBc, 面积为5 mm×5 mm。
流水线ADC 低阈值技术 保护电路 偏置电路 pipelined ADC low threshold technology protection circuit bias circuit
1 中国科学院大连化学物理研究所分子反应动力学国家重点实验室,辽宁 大连 116650
2 中国科学院大学,北京 100049
设计并搭建了一台具有高重复频率(1 MHz)和低泵浦阈值的飞秒光参量放大器(OPA)。该OPA使用掺镱飞秒光纤激光器进行泵浦,超连续白光作为种子在β-偏硼酸钡(BBO)晶体内被515 nm倍频光放大,实现了650~950 nm范围内的可调谐输出。该OPA的最高转换效率超过20%,功率稳定性可以达到0.22%,压缩后的最短脉宽小于34 fs,当1030 nm波段的脉冲能量为300 nJ时即可实现稳定输出。相比于飞秒光参量振荡器,该系统更加简单稳定;相比常规飞秒光参量放大器,该OPA具有更低的阈值,更适合高重复频率低能量的应用场景,例如多光子成像、显微瞬态吸收光谱等。
激光器 飞秒光参量放大器 低阈值 可调谐激光 高稳定性 中国激光
2022, 49(23): 2301004
1 中国科学院半导体研究所集成光电子学国家重点实验室,北京 100083
2 中国科学院大学材料科学与光电技术学院,北京 100049
3 中国科学院大学电子电气与通信工程学院,北京 100049
4 江苏华兴激光科技股份有限公司,江苏 徐州 221300
5 武汉敏芯半导体股份有限公司,湖北 武汉 430223
设计一种基于AlGaInAs材料的高速直调半导体激光器,该激光器采用脊波导、长度较短的腔和11个5 nm厚度的多量子阱结合30 nm厚度的缓变折射率分别限制异质结结构(GRIN-SCH),实现了低阈值、宽带宽和较大功率的光输出。采用均匀光栅和不对称腔面镀膜的方式实现了稳定的单纵模输出。最终制得的高速直调半导体激光器,在室温下,阈值电流为7.5 mA,3 dB小信号调制带宽可达25 GHz,大信号背靠背传输速率可达40 Gb/s,斜率效率为0.35 mW/mA,最大输出功率约为39 mW,边模抑制比可达40 dB。
激光器 1.3 μm直调激光器 宽带宽 大功率 低阈值 光学学报
2022, 42(16): 1614001
Author Affiliations
Abstract
1 Key Laboratory of Space Laser Communication and Detection Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
3 Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
A single-resonant low-threshold type-I (BBO) optical parametric oscillator (OPO) with tunable output from 410 nm to 630 nm at 5 kHz repetition rate is reported. By taking the noncollinear phase matching method, low-threshold OPO operation could be obtained compared with the configuration of collinear phase matching, and the maximum optical–optical conversion efficiency of 11.8% was achieved at 500 nm wavelength when 0.4 mJ pump pulse energy was applied. When the noncollinearity angle was preset at 1.6°, 4.8°, and 6.3°, a continuously tuning output with a total spectral range of 220 nm was successfully obtained by adjusting the phase matching angle of the BBO crystal.
optical parametric oscillator noncollinear phase matching low threshold high pulse repetition frequency widely tunable spectrum range Chinese Optics Letters
2022, 20(2): 021403
中国电子科技集团公司 第二十四研究所, 重庆 400060
提出了一种采用低阈值技术实现的高速采样保持电路。采样保持电路采用电容翻转式架构,利用栅压自举开关技术提高了采样开关的线性度,通过下极板采样技术减小了电荷注入效应。提出的放大器与传统的套筒式共源共栅极放大器在电路结构上相同。不同点在于,该放大器采用了低阈值设计技术。优势在于,在特定工艺下通过低阈值器件补偿可实现高增益带宽放大器,提高了采样保持电路的采样速率。该电路采用0.18 μm CMOS工艺设计并流片,采样时钟频率达到了125 MHz。仿真结果表明,SINAD为90.91 dB,SFDR为91.45 dBc,芯片尺寸为0.8 mm×0.5 mm。
采样保持电路 放大器 低阈值技术 S/H circuit amplifier low threshold technology
Author Affiliations
Abstract
1 Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education, School of Physics and Electronics, Hunan University, Changsha 410082, People’s Republic of China
2 State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, School of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, People’s Republic of China
Memristors have attracted tremendous interest in the fields of high-density memory and neuromorphic computing. However, despite the tremendous efforts that have been devoted over recent years, high operating voltage, poor stability, and large device variability remain key limitations for its practical application and can be partially attributed to the un-optimized interfaces between electrodes and the channel material. We demonstrate, for the first time, a van der Waals (vdW) memristor by physically sandwiching pre-fabricated metal electrodes on both sides of the two-dimensional channel material. The atomically flat bottom electrode ensures intimate contact between the channel and electrode (hence low operation voltage), and the vdW integration of the top electrode avoids the damage induced by aggressive fabrication processes (e.g. sputtering, lithography) directly applied to the channel material, improving device stability. Together, we demonstrate memristor arrays with a high integration density of 1010 cm.2, high stability, and the lowest set/reset voltage of 0.12 V/0.04 V, which is a record low value for all 2D-based memristors, as far as we know. Furthermore, detailed characterizations are conducted to confirm that the improved memristor behavior is the result of optimized metal/channel interfaces. Our study not only demonstrates robust and low voltage memristor, but also provides a general electrode integration approach for other memristors, such as oxide based memristors, that have previously been limited by non-ideal contact integration, high operation voltage and poor device stability.
2D-material robust memristor ultra-low threshold atomically flat interfaces International Journal of Extreme Manufacturing
2021, 3(4): 045103
1 南京邮电大学电子与光学工程学院、微电子学院, 江苏 南京 210023
2 南京大学电子科学与工程学院, 江苏 南京 210046
3 厦门大学, 福建 厦门 361005
激光技术的发展推动了现代科学与技术的进步,改变了人类的生活。其中微型化激光光源成为目前的研究热点之一。得益于金属等离激元的光场强局域化作用,等离激元纳米激光器不仅能够获得突破光学衍射极限的超小物理尺寸,而且可以实现大调制速度以及极小的激射阈值,从而受到广泛的关注。对国内外等离激元纳米激光器的近期进展进行了综述,从增益介质、金属种类和器件结构三个方面进行对比总结,最后对等离激元纳米激光器的未来发展潜力进行讨论和展望。
激光光学 表面等离激元 纳米激光器 衍射极限 超低阈值
广州大学物理与电子工程学院, 广东 广州 510006
对基于808 nm端面抽运的半导体可饱和吸收镜(SESAM)锁模Nd∶YVO4激光器的输出特性进行研究,通过选择不同透过率的输出镜,设计一套针对不同输出功率需求的锁模激光器方案。首先系统地研究输出镜透过率对激光锁模功率和阈值的影响,当输出镜透过率为10%,抽运功率为8 W时,得到最高输出功率为2.58 W的连续锁模脉冲输出,转换效率为32.3%。当输出镜透过率为0.1%,抽运功率为1 W时,得到低阈值连续锁模脉冲输出,输出功率为0.58 mW。然后自主搭建自相关光路测量锁模脉冲,结合自相关曲线分析锁模激光器的寄生振荡情况,通过优化输出镜抑制寄生振荡,获得纯净的锁模脉冲,其脉冲宽度为13 ps,重复频率为150 MHz。
激光器 半导体可饱和吸收镜锁模 寄生振荡 输出镜透过率 低阈值 自相关 激光与光电子学进展
2019, 56(19): 191401