Author Affiliations
Abstract
1 State Key Laboratory of Modern Optical Instrumentation, Institute for Advanced Photonics, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China
2 State Key Laboratory of Modern Optical Instrumentation, Key Laboratory of Excited State Materials of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
3 Instrumentation and Service Center for Molecular Sciences, Westlake University, Hangzhou 310024, China
Exciton-polaritons offer the potential to achieve electrically pumped perovskite polariton lasers with much lower current thresholds than conventional photonic lasers. While optically pumped exciton-polaritons have been widely studied in halide perovskites, electrically-pumped polaritons remain limited. In this study, we demonstrate the use of a solution-processing strategy to develop halide perovskite polariton light-emitting diodes (LEDs) that operate at room temperature. The strong coupling of excitons and cavity photons is confirmed through the dispersion relation from angle-resolved reflectivity, with a Rabi splitting energy of 64 meV. Our devices exhibit angle-resolved electroluminescence following the low polariton branch and achieve external quantum efficiencies of 1.7%, 3.85%, and 3.7% for detunings of 1.1, , and , respectively. We also explore devices with higher efficiency of 5.37% and a narrower spectral bandwidth of 6.5 nm through the optimization of a top emitting electrode. Our work demonstrates, to our knowledge, the first room-temperature perovskite polariton LED with a typical vertical geometry and represents a significant step towards realizing electrically pumped perovskite polariton lasers.
Photonics Research
2023, 11(10): 1791
Author Affiliations
Abstract
1 Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
2 State Key Laboratory of Modern Optical Instrumentation, Department of Optical Engineering, Zhejiang University, Hangzhou 310027, China
Colorful radiative coolers (CRCs) can be widely applied for energy sustainability especially and meet aesthetic purposes simultaneously. Here, we propose a high-efficiency CRC based on thin film stacks and engineered diffuse reflection unit, which brings out 7.1 °C temperature difference compared with ambient under ~ 700 W·m-2 solar irradiation. Different from analogous schemes, the proposed CRCs produce vivid colors by diffuse reflection and rest of the incident light is specular-reflected without being absorbed. Adopting the structure of TiO2/SiO2 multilayer stack, the nanophotonic radiative cooler shows extra low absorption across the solar radiation waveband. Significant radiative cooling performance can be achieved with the emissivity reaching 95.6% in the atmosphere transparent window (8–13 μm). Moreover, such CRC can be fabricated on flexible substrates, facilitating various applications such as the thermal management of cars or wearables. In conclusion, this work demonstrates a new approach for color display with negligible solar radiation absorption and paves the way for prominent radiative cooling.
浙江大学光电科学与工程学院现代光学仪器国家重点实验室, 浙江 杭州 310027
采用原子层沉积(ALD)技术在石英管表面制备了薄膜,研究了该薄膜的均匀性,以及石英管的内径、外径、长度对沉积薄膜均匀性的影响。以单波长减反射膜为研究对象,实验测试的反射光谱与仿真结果一致,石英管表面最低反射率可降至0.17%。忽略夹具影响,石英管外壁与内壁的减反射薄膜的非均匀性基本一致,在±1.69%范围内,内外壁表面减反射薄膜的厚度和中心波长相同,且石英管尺寸对内外壁薄膜均匀性无明显影响。利用ALD技术可在大曲率元件的内外表面沉积厚度偏差小且均匀性分布相似的减反射薄膜。
表面光学 原子层沉积 石英管 减反射膜 均匀性
1 天津津航技术物理研究所 天津市薄膜光学重点实验室, 天津 300308
2 浙江大学 现代光学仪器国家重点实验室, 浙江 杭州 310027
3 成都七中高新校区, 四川 成都 610209
基于SiO2/Al/SiO2三层夹层结构, 结合使用多角度椭圆偏振谱和透射光谱精确反演获得了薄金属Al层光学常数, 并研究分析了Al光学常数随膜层厚度的变化; 在此基础上采用导纳匹配法, 理论优化获得了三腔金属诱导透射紫外滤光膜, 并系统分析了Al和SiO2介质匹配层制备误差对紫外滤光膜光谱性能的影响; 进一步采用低温、高真空Al、SiO2薄膜生长工艺, 成功获得了峰值波长位于218 nm附近, 峰值透过率~23.1%, 带宽~32 nm, 在280 nm、318 nm波段的透过率分别约为0.5%和0.04%, 400～700 nm、800~1 100 nm波段的截止度分别可达~5.0 OD、~4.5 OD的高性能三腔诱导透射紫外滤光片样品。相关研究结果对于高性能多腔诱导透射“日盲”紫外滤光片的设计与制备具有很好的指导意义。
光学薄膜 电子束蒸发 紫外诱导透射 thin film electron beam evaporation UV induced filter Al/SiO2 Al/SiO2 红外与激光工程
2018, 47(9): 0920002
Author Affiliations
Abstract
1 Ultrafast Laser Laboratory, Key Laboratory of Opto-electronic Information Technology (Ministry of Education), School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China
2 Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO 80523, USA
3 State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310027, China
We demonstrate a nonlinearity optimization method by altering distribution of passive fibers in a dissipative-soliton mode-locked fiber laser to level up output parameters. In the numerical simulation, we found that the passive fiber segment after gain fiber characterizes the highest average B-integral among fiber segments. By reducing the length of this fiber section and keeping the total passive fiber length as constant, the output pulse energy can be effectively scaled up while maintaining a short dechirped pulse duration, resulting in boosting peak power. With this method, 37-nJ pulses are generated from a dissipative-soliton mode-locked cladding pumped ytterbium-doped single-mode fiber laser in the experiment. The pulse can be dechirped to 66 fs with 350 kW peak power. Moreover, the pulse pedestal is suppressed by a vector-dispersion compressor.
fiber optics amplifiers and oscillators ultrafast lasers. High Power Laser Science and Engineering
2018, 6(2): 02000e27
浙江大学光电科学与工程学院现代光学仪器国家重点实验室, 浙江 杭州 310027
研究了离子束溅射(IBS)制备的Nb2O5、Ta2O5和SiO2薄膜的光学特性、力学特性以及薄膜微结构,分析了辅助离子源电压对薄膜特性的影响,并将电子束蒸发、离子辅助沉积和IBS制备的薄膜进行了对比。研究结果表明,IBS制备的薄膜具有更好的光学特性和微结构,同时具有较大的压应力、硬度和杨氏模量;辅助离子源可以改善薄膜的光学特性,调节薄膜应力和减小薄膜表面粗糙度,但对硬度和杨氏模量的影响相对较小。在不同的辅助离子源电压下,IBS制备的Nb2O5应力为-152~-281 MPa, Ta2O5的应力为-299~-373 MPa,SiO2的应力为-427~-577 MPa;在合适的工艺参数下,消光系数可小于10
-4;薄膜表面平整,均方根粗糙度小于0.2 nm。
薄膜 光学特性 机械特性 应力 微结构 离子束溅射 光学学报
2017, 37(12): 1231001
浙江大学光电科学与工程学院现代光学仪器国家重点实验室, 浙江 杭州 310027
设计和制备了一种用于1064 nm分振幅光偏振测量仪(DOAP)的具有多层介质薄膜结构的差分相移分束镜。通过理论分析该DOAP系统的仪器矩阵参数, 得到分束镜的最优参数, 并用离子束溅射沉积方法制备了分束镜样品及其背面的减反射膜, 其实测结果与设计值吻合较好。与单层薄膜分束镜相比, 多层介质薄膜分束镜不受基板、膜层材料, 以及入射角和工作波长的限制, 具有更广泛的应用。
薄膜 分束镜 相位延迟 偏振测量 多层介质膜
浙江大学现代光学仪器国家重点实验室, 浙江 杭州 310027
以乙酰丙酮铱[Ir(acac)3]和高纯氧为前驱体，采用原子层沉积(ALD)方法在基板温度为340 ℃的石英玻璃和硅基板上制备了金属铱薄膜。采用反射光谱测试仪、X射线电子能谱（XPS）、X射线衍射（XRD）、扫描电子显微镜(SEM)和原子力显微镜(AFM)等手段对不同厚度薄膜的微结构、表面形貌和光学性能进行了研究。结果表明，原子层沉积制备的Ir薄膜中元素纯度较高（大于95%），表面粗糙度低，并呈现多晶纳米颗粒。同时，Ir薄膜在紫外波段表现出较好的光学特性，可以用于制作Ir金属紫外光栅等光学器件。
薄膜 原子层沉积 Ir薄膜 光学特性 光学学报
2014, 34(10): 1031002
Author Affiliations
Abstract
A scanning white-light interferometer is built for precisely measuring phase properties of dispersive multilayer thin film structure with the aid of the commercial spectrometer. Combining seeking optimal function for interferogram maximas with wavelet denoising algorithm, a novel time-domain algorithm is presented which enables the direct extraction of group delay and thus obtains a remarkable decrease of noise level in group delay and group delay dispersion. The apparatus shows reasonable potential for multilayer measurement, material characterization, displacement measurement as well as profilometry.
310.6845 Thin film devices and applications 310.6188 Spectral properties 320.7090 Ultrafast lasers 300.6300 Spectroscopy, Fourier transforms Chinese Optics Letters
2013, 11(s1): S10302
Author Affiliations
Abstract
Trimethylamine (TMA), TiCl4, and water are applied as the precursors to deposit Al2O3 and TiO2. With different substrate temperatures, the optical properties and surface morphologies of the two oxides TiO2 and SiO2 are studied, respectively. With substrate temperature of 120 oC, amorphous TiO2 can be obtained, and the surface roughness (RMS) is only 0.928 nm. Applying Al2O3 and TiO2 deposited in 120 oC as low and high refractive index materials, anti-reflection (AR) coating at single point (550 nm) is designed. Furthermore, with the calibrated growth rates, this AR coating is fabricated, and its ultimate reflectance for the AR coating at 550 nm is less than 0.2%, which can meet the requirement for most applications.
310.1210 Antireflection coatings 310.1860 Deposition and fabrication 310.6860 Thin films, optical properties Chinese Optics Letters
2013, 11(s1): S10205
