Fig. 1. Designed CPS^[14]. (a) Schematic diagram of bidirectional designed CPS; (b) forward temperature rise test diagram of CPS with 2000 W input power; (c) backward temperature rise test diagram of CPS with 2000 W input power

Fig. 2. Pictures of fiber end caps with different shapes (left) and packaged fiber end caps developed for 30 kW high-power laser system (right)^[15]

Fig. 3. Schematic diagram of two-stage cascaded side pump structure^[20]

Fig. 4. Schematic diagram of end pump/signal combiner structure^[30]

Fig. 5. End pump/signal combiner based on heating core expansion technology^[32]. (a) End face of fiber bundle before core expansion; (b) end face of fiber bundle after core expansion; (c) microscopic view of side face after fusion of combiner

Fig. 6. End pump/signal combiner with multiple mode field adapter structures^[37]. (a) Schematic diagram of overall structure of combiner; (b) schematic diagram of end face structure of fiber bundle; (c) schematic diagram of output fiber structure

Fig. 7. Cross sectional view of fiber bundle^[40]. (a) Schematic diagram of fiber bundle with pores; (b) schematic diagram of fiber bundle after penetrating signal fiber

Fig. 8. Structure diagram of 7 × 1 fiber power combiner with 50 μm output core diameter^[47]. (a) Schematic diagram of overall structure of combiner; (b) schematic diagram of end face structure of fiber bundle; (c) schematic diagram of output fiber structure

Fig. 9. Structure diagram of kilowatt level integrated oscillator^[27]