808 nm半导体分布反馈激光器的光栅设计与制作

半导体分布反馈（ DFB）激光器的核心工艺之一是分布反馈光栅的制作，设计了808 nm DFB激光器的一级光栅结构。利用纳米压印技术与干法刻蚀附加湿法腐蚀制作了周期为120 nm的梯形布拉格光栅结构，使用MATLAB和Pics3D软件模拟了一次外延结构的光场分布和能带图。通过优化湿法腐蚀所用腐蚀液各组分比例、腐蚀温度、腐蚀时间等条件，得到了理想的湿法腐蚀工艺参数。扫描电子显微镜表征显示，光栅周期为120 nm，光栅深度约为85 nm，占空比约为47%，光栅边缘线条平直，表面平滑，周期均匀。创新型的引入湿法腐蚀工艺和腐蚀牺牲层使光栅表面的洁净度得到保证，提高了二次外延质量的同时，也为进一步制作DFB激光器高性能芯片奠定了良好的基础。     

采用纳米压印技术制作DWDM激光器的研究

 适合DWDM系统应用的高性能DFB半导体激光器是现代光通信系统中发射机的核心光电子器件,光栅的设计和制作是决定器件性能的关键因素之一。目前,基于MOCVD设备的材料外延技术趋于稳定,高速器件封装技术也已经成熟,满足DWDM需求的DFB光栅的加工渐渐成为进一步降低成本的一个瓶颈。本文利用纳米压印技术制作DFB激光器光栅。结果表明,利用纳米压印技术制作出来的DFB激光器性能不逊于用EBL直接制作出的高性能激光器,不仅可以满足DWDM系统的要求,而且还具有生产效率高、成本低的优点。     

全息光刻制备808nm分布反馈半导体激光器的光栅

实验优化设计了808 nm分布反馈(DFB)半导体激光器的二级布拉格光栅结构,介绍了808 nm DFB半导体激光器光栅制备的工艺过程。采用全息光刻方法和湿法腐蚀技术在Ga As衬底片上制备了周期为240 nm的光栅图形,全息光刻系统采用条纹锁定技术降低条纹抖动和提高干涉稳定性,腐蚀液中H3PO4、H2O2和H2O的体积比为1:1:10,腐蚀时间为30 s。光学显微镜、扫描电子显微镜(SEM)和原子力显微镜(AFM)测试显示,光栅周期为240 nm,占空比为0.25,深度为80 nm,具有完美的表面形貌及良好的连续性和均匀性。     

纳米压印技术制作CWDM系统用DFB激光器阵列

使用纳米压印技术制作了用于1.3um CWDM系统的四通道单片集成折射率耦合DFB半导体激光器。得到了符合设计的20nm通道间隔激射波长。结果显示纳米压印技术在制作DFB半导体激光器方面是成熟可靠的。     

用于1.55μm InGaAsP/InP DFB激光器的λ/4相移衍射光栅

采用全息二次曝光的方法,研制出用于 1.55μm InGaAsP/InP DFB激光器的,具有 λ/4相移的二级光栅,并通过扫描电镜(SEM)证明了相移的存在.本文分析了制备该种光栅的工艺原理,并提出了改善此种光栅质量的新方法.     

DFB光纤激光器中相移光栅优化分析

相移光栅在光通信领域具有较高的应用价值,文中用传输矩阵法,详细分析了相移光栅中相移量,折射率调制深度,相移位置及光栅长度对相移光栅的影响,并结合相移光栅在DFB光纤激光器中的应用进行了分析。分析表明,实际制作DFB光纤激光器时,应根据实际应用场合,对相移光栅的相关参数进行设计,从而提高光纤激光器性能。     

808nm DFB半导体激光器的光栅制备

实验优化设计了808nm DFB半导体激光器的二级布拉格光栅结构,介绍了808 nm分布反馈（DFB）半导体激光器光栅制备的工艺过程。采用全息光刻方法和湿法腐蚀技术在GaAs衬底片上制备了周期为240nm的光栅图形,全息光刻系统采用条纹锁定技术降低条纹抖动和提高干涉稳定性,腐蚀液采用H3PO4 : H2O2 : H2O (1 : 1 : 10),腐蚀时间为30s。光学显微镜、扫描电子显微镜（SEM）和原子力显微镜（AFM）测试显示,光栅周期为240nm,占空比为0.25,深度为80nm,具有完美的表面形貌,及良好的连续性和均匀性。     

亚微米光栅曝光系统的应用及设备关键技术研究

半导体工艺中的光刻是芯片制造中最关键的工艺。DFB半导体激光器的腔体结构与普通半导体激光器的腔体结构不同,需要制作周期光栅,光栅周期为亚微米数量级;鉴于亚微米光栅曝光系统在半导体激光器的应用需求,瑞士一家公司研制了一款专用于亚微米周期光栅的设备Phabler 100M DUV光刻机;本系统采用了非线性晶体的倍频效应和周期性光栅的泰伯效应。这些关键技术用较低的成本实现了极高的分辨率,可以制作周期性光栅并达到100 nm的线条分辨率;掩模版和晶片的不平行将造成光刻线条的不均匀,应用CCD探测器和计算机相结合的办法是做平行度的关键调试。     

基于表面曲线光栅的高功率窄线宽半导体激光器

随着智能感知技术的快速发展，高功率、窄线宽的半导体激光光源成为研究热点。通过在边发射半导体激光器件表面引入高阶曲线光栅，设计了一种独特的非稳谐振腔结构，可实现高功率和窄线宽。采用紫外光刻和电感耦合等离子体（ICP）刻蚀技术，制备了周期为6.09μm、占空比为0.66、刻蚀深度为500 nm的曲线光栅。在室温条件下，测得腔长为2 mm的器件的阈值电流为220 mA，连续输出功率为1.48 W，斜率效率为0.63 W/A。比较了法布里-珀罗激光器、直线光栅分布式反馈（DFB）激光器和曲线光栅DFB激光器的光谱，结果表明，曲线光栅对半导体激光器的模式选择起到了关键作用，有利于实现高功率DFB激光器的窄线宽单模输出。该器件具有制作工艺相对简单、性能优异、可靠性高等特点，具有广阔的应用前景。     

高线密度X射线双光栅的研制

研究了采用高分辨率的100 kV电子束光刻和光学光刻系统相结合制作高线密度X射线双光栅的工艺技术,并且分析了电子束邻近效应校正技术在高线密度光栅制备中的应用。首先,利用电子束曝光和纳米电镀技术在同一衬底上制备两种不同线密度光栅图形;然后,利用光学光刻在2 000 lp/mm光栅上制备了自支撑加强筋结构。通过此技术制备的X射线双光栅成功集成了高线密度5 000 lp/mm透射光栅和2 000 lp/mm自支撑透射光栅,其栅线宽度分别为100和250 nm,金吸收体厚度达到400 nm。     

975nm分布反馈激光器一级光栅的制备

优化设计了975 nm分布反馈激光器的一级布拉格光栅结构.将纳米压印技术与干法刻蚀工艺相结合制备周期为148 nm的光栅结构,通过优化调整刻蚀气体流量比、腔室压强和偏压功率等参数,得到了合适的光栅刻蚀工艺参数.扫描电子显微镜测试显示,光栅周期为148 nm,占空比接近50％,深度合适,表面形貌、连续性和均匀性良好.将所制备光栅应用于975 nm分布反馈激光器中,激光器输出性能良好,波长随温度漂移系数小,光栅对波长的锁定效果良好.     

DFB LD manufactured by nanoimprint lithography

Gratings of distributed feedback laser diodes (DFB LDs) have been successfully manufactured by nanoimprint lithography (NIL). Uniform gratings with periods of about 240 nm and phase-shifted in the center have been fabricated by a soft press NIL employing a polymer stamp technology. Moreover, the shape of the grating is rectangle, rather than sinusoidal by holography.The test results show good characteristics of the electrical and spectral output. The results of this study indicate that NIL has high potential for the manufacture of DFB LDs.     

Fabrication of second-order gratings for 1.55 μm DFB lasersusing deep UV lithography

Second-order gratings for 1.55 μm DFB lasers have been fabricated on InP substrate using contact deep UV (220 nm) lithography. Localised gratings with a 0.48 μm pitch were clearly resolved in PMMA photoresist and then transferred in InP by wet chemical etching     

Fabrication of highly reflective gratings in 1.5 μm semiconductor lasers using focused ion beam-based etching

This paper reports on fabrication of semiconductor/air gratings in 1.5 μm double-section semiconductor lasers to achieve a high reflectivity in order to compensate low round-trip gain. Fabrication of the gratings with varying thicknesses and with thicknesses down to 160 nm is carried out at the gain section of the double-section diode laser using focused ion beam etching (FIBE) and inductively coupled plasma (ICP) techniques. Theoretical results of reflectivity are given for 1.5 μm AlGaInAs/InP semiconductor lasers by adding wavelength dependence of the refractive index into the calculations. We also compare our reflectivity results with that of a commercial simulation program and show a good agreement between them. Our results demonstrate that the gratings fabricated consist of only six air/semiconductor layer pairs and achieve theoretical reflectivity higher than 99%. Due to a high index contrast of the both layers, n_l = 1, n_h ∼ 3.5, a reflectivity bandwidth of >230 nm is obtained in 1.5 μm semiconductor lasers. Finally, lasing operation from AlGaInAs/InP semiconductor lasers with highly reflective grating section is achieved with a low threshold current of ∼8 mA, which is almost three times lower than devices without semiconductor/air gratings.     

软X射线偏折仪用自支撑莫尔光栅研制

介绍了莫尔光栅制作的主要方法和进展。利用紫外光刻、离子束刻蚀技术制作自支撑金莫尔光栅，讨论了金膜厚度要求、电镀金膜质量和光栅占空比控制等影响莫尔光栅质量的关键技术问题。实验结果表明，通过设计较小占空比的光栅掩模、紫外光刻时擦除基片边缘的光刻胶棱以消除衍射效应、离子束刻蚀时基片倾斜一定的角度旋转刻蚀等措施可以改善自支撑金莫尔光栅的占空比。     

多能点X射线透射光栅的制作技术

针对X射线自支撑透射光栅在多能点单色成像光栅谱仪中的应用,采用电子束和光学匹配曝光、微电镀和高密度等离子体刻蚀技术,成功制备了周期为500nm、金吸收体厚度为350nm、占空比接近1∶1,满足三个能点成像需求的2000lp/mm X射线自支撑透射光栅。首先利用电子束光刻和微电镀技术制备金光栅图形,然后采用紫外光刻和微电镀技术制作自支撑结构,最后通过腐蚀体硅和感应耦合等离子体刻蚀聚酰亚胺完成X射线自支撑透射光栅的制作。在电子束光刻中,采用几何校正和高反差电子束抗蚀剂实现了对纳米尺度光栅图形的精确控制。实验结果表明,同一个器件分布的三块光栅占空比合理,栅线平滑,可以满足单能点单色成像谱仪的要求。     

Low cost, rapid fabrication of durable molds of grating arrays for nanoimprint lithography

This study proposes a new fabrication method for the mold of a sub-micron grating array used in the nanoimprint lithography process. In general, the mold of a sub-micron grating array is fabricated by electron beam lithography (EBL) and reactive ion etching (RIE), and then, nanoimprint lithography (NIL) is used to achieve the required amount of replication. Such a method is expensive and has a low throughput, and the pattern is limited by the original mold. In this paper, we constructed a durable mold of a sub-micron grating array with good adaptability, using a commercial epoxy grating (EG) and a hybrid inorganic/organic sol-gel material combined with nanoimprint lithography and photolithography. Due to its low cost and ease of use, this method is suitable for both laboratory research and mass production without the need for expensive equipment like EBL or RIE.     

基于液晶/聚合物光栅选频的高效率有机半导体激光器

报道了一种基于液晶/聚合物光栅选频的高效率有机半导体激光器的制备方法。首先在一片玻璃基板上旋涂有机半导体荧光薄膜MEH-PPV作为增益介质,然后在其上通过光场中的定域光聚合制备液晶/聚合物光栅,形成分布式反馈(DFB)有机半导体激光器。激光出射阈值0.32μJ/pulse,斜率转化效率高达7.8%,呈现良好的s偏振特性。采集了激光束的光斑,轮廓清晰,呈现扇形结构。通过改变光栅周期,实现了53.4nm激光出射范围。本工作为新型有机激光器的制备提供了有益的指导和借鉴意义。     

Monolithic DWDM source with precise channel spacing

We report a low-cost manufacturing approach for fabricating monolithic multi-wavelength sources for dense wavelength division multiplexing(DWDM)systems that offers high yield and eliminates crystal regrowth and selective area epitaxy steps that are essential in traditional fabrication methods.The source integrates an array of distributed feedback(DFB)lasers with a passive coupler and semiconductor optical amplifier(SOA).Ridge waveguide lasers with sampled Bragg side wall gratings have been integrated using quantum well intermixing to achieve a fully functional four-channel DWDM source with 0.8 nm wavelength spacing and residual errors<0.13 nm.The output power from the SOA is>10 mW per channel making the source suitable for use in passive optical networks(PONs).We have also investigated using multisection phase-shifted sampled gratings to both increase the effective grating coupling coefficient and precisely control the channel lasing wavelength spacing.An 8-channel DFB laser array with 100 GHz channel spacing was demonstrated using a sampled grating with twoπ-phase-shifted sections in each sampling period.The entire array was fabricated by only a single step of electron beam lithography.     

Electrical control of the distributed feedback organic semiconductor laser based on holographic polymer dispersed liquid crystal grating

In this paper, we demonstrate the electrical control of the distributed feedback (DFB) organic semiconductor laser based on a holographic polymer dispersed liquid crystal (HPDLC) grating for the first time. The grating is fabricated on the top of the organic semiconductor film to act as an external feedback structure. Experimental results show that the lasing intensity can be decreased by increasing the external electric field, and the lasing wavelength exhibits a slight blue-shift of 1.4 nm during the modulation process, indicating a good stability. The modulated performances are attributed to the decreases in the refractive index modulation and average refractive index of the HPDLC grating respectively as a result of the field-induced liquid crystal reorientation. This study provides some new ideas for the improvement of DFB organic semiconductor laser to enable envisioned applications in laser displays and integrated photonic circuits.