Author Affiliations
Abstract
1 School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
2 Key Laboratory of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Laboratory of Modern Optical Technologies of the Ministry of Education, Soochow University, Suzhou 215006, China
3 School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore
Photoelectric logic gates (PELGs) are the key component in integrated electronics due to their abilities of signal conversion and logic operations. However, traditional PELGs with fixed architectures can realize only very limited logic functions with relatively low on–off ratios. We present a self-driving polarized photodetector driven by the Dember effect, which yields ambipolar photocurrents through photonic modulation by a nested grating. The ambipolar response is realized by exciting the whispering-gallery mode and localized surface plasmon resonances, which leads to reverse spatial carrier generation and therefore the contrary photocurrent assisted by the Dember effect. We further design a full-functional PELG, which enables all five basic logic functions (“AND”, “OR”, “NOT”, “NAND”, and “NOR”) simultaneously in a single device by using one source and one photodetector only. Such an all-in-one PELG exhibits a strong robustness against structure size, incident wavelength, light power, and half-wave plate modulation, paving a way to the realization of ultracompact high-performance PELGs.
Photonics Research
2023, 11(7): 1148
1 中国电子科技集团公司第三十八研究所微波光子学研究中心, 安徽 合肥 230088
2 西北核技术研究所高功率微波技术重点实验室, 陕西 西安 710024
为实现超宽带的微波/毫米波测试，基于飞秒激光技术设计并搭建了一套光学谐波混频系统。该系统采用飞秒激光脉冲序列作为光载波，利用飞秒脉冲包络信号的高次谐波与被测信号进行混频，将被测信号下变频至直流进行进一步测量。由于飞秒脉冲序列特有的宽带谐波成分，该系统能够实现100 GHz 以上测试带宽。利用该系统分别测试了6.56 GHz 与100 GHz 的天线口面场的电场幅度分布，并与微波仿真结构进行了比较，实验与仿真结果吻合，验证了该设计的正确性。设计中采用的谐波混频器为基于泡克耳斯效应的铌酸锂电光晶体。
超快光学 谐波混频 电光效应 超宽带 激光与光电子学进展
2015, 52(9): 093201
Author Affiliations
Abstract
We present a review of the development of a compact and high-power broadband terahertz (THz) source optically excited by a femtosecond photonic crystal fiber (PCF) amplifier. The large mode area of the PCF and the stretcher-free configuration make the pump source compact and very efficient. Broadband THz pulses of 150 μW extending from 0.1 to 3.5 THz are generated from a 3-mm-thick GaP crystal through optical rectification of 12-W pump pulses with duration of 66 fs and a repetition rate of 52 MHz. A strong saturation effect is observed, which is attributed to pump pulse absorption; a Z-scan measurement shows that three-photon absorption dominates the nonlinear absorption when the crystal is pumped by femtosecond pulses at 1 040 nm. A further scale-up of the THz source power is expected to find important applications in THz nonlinear optics and nonlinear THz spectroscopy.
320.7110 Ultrafast nonlinear optics 300.6495 Spectroscopy, teraherz 060.5295 Photonic crystal fibers 060.2320 Fiber optics amplifiers and oscillators Chinese Optics Letters
2011, 9(11): 110005
Author Affiliations
Abstract
We investigate the optical response of silicon-based VxOy film for terahertz (THz) transmission. We find that absorption of the THz wave by the film can be controlled by laser excitation. Using THz time-domain spectroscopy (THz-TDS), we observe that the amplitude of the THz pulse is modulated by the external optical beam. The linearity of the optical modulation is also analyzed. Weak modulation nonlinearity is found to be within tolerable range.
040.2235 Far infrared or terahertz 140.0140 Lasers and laser optics Chinese Optics Letters
2011, 9(s1): s10207
Author Affiliations
Abstract
We present a systematic study of freestanding terahertz (THz) metamaterials fabricated on Mylar film by self-aligned photolithography. THz time-domain spectroscopy (THz-TDS) transmission measurements and numerical simulations reveal the negative index of refraction in the frequency range of 0.66–0.90 THz under normal wave incidence. The observed resonance behaviors can be explained by a theoretical circuit model. The electromagnetic properties of such close-ring metamaterials are also explored in terms of geometrical parameters of the unit cell, thickness of the dielectric film, and conductivity of the close ring. This flexible metamaterial can pave the way for three-dimensional THz metamaterial fabrication and applications.
160.3918 Metamaterials 260.5740 Resonance Chinese Optics Letters
2011, 9(s1): s10404
Author Affiliations
Abstract
Nonlinear processes associated with terahertz radiation generated via optical rectification from undoped GaP crystal, including second harmonic generation (SHG) and multiphoton absorption processes, are examined. Experimental results of polarization-resolved SHG are obtained.
190.7110 Ultrafast nonlinear optics 190.4720 Optical nonlinearities of condensed matter 320.7130 Ultrafast processes in condensed matter, including semiconductors Chinese Optics Letters
2011, 9(s1): s10201
Author Affiliations
Abstract
Center for Terahertz Waves and Ultrafast Laser Laboratory, College of Precision Instrument and Optoelectronics Engineering, Key Laboratory of Opto-Electronics Information and Technical Science (Ministry of Education), Tianjin University, Tianjin 300072, China
Conventional analytical methods in the wavelet domain are used to present an analysis of terahertz (THz) waveguide modes. To obtain THz radiation pulses passing through a waveguide, we build a simple experimental system with a 5-mm-long, 230-\mum-inner-diameter stainless steel waveguide. The single-mode guided signal from the experiments and the multi-mode signal of a similar THz waveguide reported in the literature are analyzed using the continuous wavelet transform (CWT). The results demonstrate that analyzing THz waveguide modes in the wavelet domain not only possesses all the functionality of the traditional THz time-domain spectroscopy (TDS) data processing but also has the ability to unscramble quantitatively and intuitively detailed information about the target samples, such as mode type, cut-off frequency, amplitude distinction, and group velocity.
太赫兹光谱学 波导 300.6495 Spectroscopy, teraherz 230.7370 Waveguides Chinese Optics Letters
2010, 8(11): 1057
天津大学精密仪器与光电子工程学院超快激光研究室 教育部光电信息技术科学重点实验室, 天津 300072
光子晶体光纤(PCF)呈现出许多在传统光纤中难以实现的特性：可灵活设计的色散特性、增强的光学非线性特性、在极宽谱带内单模传输特性和增强的双折射特性等, 使其从一出现便受到了广泛关注并成为近年来光学与光电子学研究的一个热点, 在飞秒激光技术中得到了广泛的应用并极大地提高了锁模光纤激光器的输出水平。尤其以掺增益介质的双包层光子晶体光纤为代表的新型光纤激光技术的出现极大地推动了飞秒激光技术的普及化。阐述了近年来基于光子晶体光纤的飞秒激光振荡器、放大器方面的研究进展及其前沿应用。
飞秒激光技术 光子晶体光纤 大模场面积 太赫兹辐射 非线性光学 微加工
