5 kW Near-Diffraction-Limited and 8 kW High-Brightness Monolithic Continuous Wave Fiber Lasers Directly Pumped by Laser Diodes

Abstract

Tandem pumping technique are traditionally adopted to develop >3-kW continuous-wave (cw) Yb 3+ -doped fiber lasers, which are usually pumped by other fiber lasers at shorter wavelengths (1018 nm e.g.). Fiber lasers directly pumped by laser diodes have higher wall-plug efficiency and are more compact. Here we report two high brightness monolithic cw fiber laser sources at 1080 nm. Both lasers consist of a cw fiber laser oscillator and one laser-diode pumped double cladding fiber amplifier in the master oscillator-power amplifier configuration. One laser, using 30-µm-core Yb 3+ -doped fiber as the gain medium, can produce >5-kW average laser power with near diffraction-limited beam quality (M 2 <1.8). The slope efficiency of the fiber amplifier with respect to the launched pump power reached 86.5%. The other laser utilized 50-µm-core Yb 3+ -doped fiber as the gain medium and produced >8-kW average laser power with high beam quality (M 2 : ∼ 4). The slope efficiency of the fiber amplifier with respect to the launched pump power reach 83%. To the best of our knowledge, this is the first detailed report for >5-kW near-diffraction-limited and >8-kW high-brightness monolithic fiber lasers directly pumped by laser diodes.

Influence of beam shape on piston and tilt error in coherent combined laser array

“…[6][7][8] To date, severalkilowatt average powers from single-aperture solid-state lasers have been demonstrated. [9][10][11] Another approach for power scaling is to use multiple lasers with relatively small output powers and combine them to obtain a single-aperture laser propagation characteristic. This class of techniques is called laser beam combining, and it can be divided into two general groups: coherent beam combining (CBC) and wavelength beam combining (WBC).…”

Высокомощные Волоконные Объединители

“…Учитывая величину порога разрушения волокна 10 Вт/мкм 2 , получаем, что допустимый диаметр поля моды должен составлять не менее 36 мкм. Так в работе [3] указано, что в волокне с диаметром сердцевины 50 мкм и с числовой апертурой NA = 0,06 была достигнута мощность 8 кВт, при этом параметр М 2 составлял примерно четыре единицы. Дальнейшее наращивание мощности требует увеличения диаметра сердцевины и приведет к переходу в многомодовый режим.…”

“…Considering the value of the fiber breakage threshold of 10 W/μm 2 we receive that the admissible diameter of the mode field must be at least 36 μm. Thus, [3] indicates that the fiber with a core Высокомощные Волоконные объединители Н.В. Буров 1 , n.burov@oessp.ru, Дж.…”

“…Буров 1 , n.burov@oessp.ru, Дж. Лин 2 , Jason.lin@lightcomm.com, В.Б.Ромашова 1,3 , vasyokjk@gmail.com, v.romashova@oessp.ru 1 ООО "ОЭС Спецпоставка", С-Пб, Россия; 2 LightComm Technology Co, Jia'an Industry Park, Xin'an Subdistrict, Shenzhen, Китай; 3 Санкт-Петербургский Государственный Университет Аэрокосмического Приборостроения, С-Пб, Россия, Надежность сплавных волоконных компонентов в волоконно-оптических лазерных системах обеспечивает высокий уровень мощности излучения. В статье описаны основные проблемы создания волоконных объединителей и методы их решения для минимизации энергетических потерь и сохранения качества пучка.…”

Solution-processed two-dimensional materials for ultrafast fiber lasers (invited)

“…low linear absorption and high modulation depth), and that can be easy to fabricate and integrate, are especially desirable [23,24]. These requirements, driven by a growing number of scientific and industrial applications, motivate research on new materials, novel designs, and technologies [25][26][27][28].…”