An efficient, compact Ho:YLF MOPA system pumped by a linearly polarized Tm:YAP laser

• A 61.1 W compact Ho:YLF MOPA system is reported. • A 101 W linearly polarized Tm:YAP slab laser is used as a pump source. • The Ho:YLF MOPA system’s optical-to-optical efficiency is up to 62.8%. We demonstrated a high optical-to-optical efficiency, compact Ho:YLF MOPA system operating at room temperature. The pump source was a 1937.8 nm linearly polarized Tm:YAP slab laser. At the PRF of 10 kHz, the maximum average output power of the oscillator and the amplifier were 51.1 W and 61.1 W, with the incident pump power of 97.3 W, respectively. The optical-to-optical efficiency of the MOPA system was up to 62.8%. As far as we know, it is the most efficient Ho:YLF MOPA system with a compact structure. The highest per pulse energy was 6.1 mJ with a pulse width of 22.5 ns, corresponding to a peak power of 265.2 kW. Besides, the beam quality was excellent with the M 2 factor of ∼1.1.