实验课程是工科类专业学生学习内容的重要组成部分。实验课程配备的资源应满足教学需求，但在实际操作中，仍然存在资源有限问题，如仪器台套数不足、可操作功能不丰富、创新思考空间有限等。针对山东科技大学材料科学与工程学院基础实验课程有限资源的问题，对新能源材料与器件专业现有的实验课程资源进行归类和分析，提出了优化实验课程思路。根据实验学时和设备条件，将学习重点放在仪器认识、样品制备、参数选择、结果处理、技能和思路训练方面。在课程规划环节，优化实验课程安排和设备的配置；在知识回顾与学习环节，穿插了解应用实例；在操作仪器环节，设置思考项目、变量因素，让学生相互指导、找寻规律；在课前预习和课后自习环节，引入虚拟仿真技术、线上资源。这为专业技术实验、综合实验等课程的开展提供了新的思路。

综合实验课程以“锂离子电池”这一研究和发展热点为主题，依托新能源专业，以工程实际问题为切入点，采用固相合成法制备了锂离子电池用钛酸锂负极材料，并进行表征和电化学性能测试。教学设计围绕以学生为中心、以成果为导向的理念，与新能源材料合成与制备、材料分析测试方法等课程相结合。教学内容涉及材料制备与表征、电极制备与电池组装、性能测试与结果分析。该教学实验的设计和实践有助于学生深化理论理解，掌握基本的锂离子电池制作流程和测试方法，进一步认识所学课程在新能源领域发展中的重要作用，提高专业认同感、自主思考能力和创新意识。

In this work, we investigate the possibility of achieving nanojoule level pulse energy in an all-fiber Er-doped oscillator by using a graded index multimode fiber (GIMF) as the saturable absorber (SA). This GIMF-based SA demonstrates the desirable characteristics of high-power tolerance, large modulation depth of 29.6%, and small saturation fluence of ～7.19×10 3μJ/cm2, which contribute to the high-energy soliton generation. In the experiments, the oscillator generates stable ultrafast pulse trains with high pulse energy/average output power up to 13.65 nJ/212.4 mW in the anomalous regime and 6.25 nJ/72.5mW in the normal regime, which are among the highest energy/average output power values achieved by all-fiber Er lasers. The results obtained demonstrate that the GIMF-based SA can be used as an effective photonic device for high-energy wave-breaking free pulse generation.

A wavelength-tunable and dual-wavelength mode-locking operation is achieved in an Er-doped fiber laser using a hybrid no-core fiber graded index multimode fiber as the saturable absorber. In the tuning operation, continuously wavelength-tunable pulses with a tuning range of 46.7 nm, stable 3-dB bandwidth of around 5 nm, and pulse duration of ～850fs are obtained by increasing the intracavity loss of a variable optical attenuator. In the dual-wavelength operation, the two solitons at different wavelengths demonstrate the characteristics of mutual coherence. By increasing the intracavity loss, the spectral spacing can be tuned from 11 to 33.01 nm while maintaining the coherence of the solitons. Such coherent solitons have high potential for applications in dual-comb frequency and multicolor pulses in nonlinear microscopy.

A hybrid no-core fiber (NCF)–graded index multimode fiber (GIMF) structure is used as a saturable absorber (SA) for mode-locked laser operation. Such an SA supports various types of soliton outputs. By changing the cavity parameters, not only the spatiotemporal mode-locking states with a stable single pulse but also tightly and loosely bound solitons are generated. Single 35.5 pJ solitons centered at 1568.5 nm have a 4 nm spectral full-width at half-maximum and an 818 fs temporal duration. Tightly bound soliton pairs with continuously tunable wavelength from 1567.48 nm to 1576.20 nm, featured with an ～700 fs pulse train with a separation of 2.07 ps, have been observed by stretching the NCF-GIMF structured device. Meanwhile, several different pulse separations from 37.57 ps to 56.46 ps of loosely bound solitons have also been realized. The results provide help in understanding the nonlinear dynamics in fiber lasers.