按照SCI论文要求润色：Tm-Ho co-doped laser materials are highly desirable for simple and high power 21 μm laser systems they can be optically pumped by commercially available laser diodes LDs around 785nm and a

Tm-Ho co-doped laser materials are highly desirable for the development of simple and high power 2.1 μm laser systems. These materials can be optically pumped by commercially available laser diodes (LDs) operating at around 785nm, and achieve laser operation through efficient cross-relaxation and rapid energy transfer processes.