0.7 MW Output Power from Coherently Combined Q-switched Photonic Crystal Fiber Laser

Single-channel Q-switching in a system of coherently combined fiber lasers

“…2). In addition, the output power characteristics found in the current study are similar to those reported in a previous study [8], wherein both channels were directly Q-switched, which further supports our claim. Finally, the pulse energy at 10-kHz repetition rate is confirmed by an additional measurement with an energy meter; due to perfect correlation, we can conclude that no parasitic lasing exists between the pulses so that both channels operate in a synchronized manner.…”

“…Higher pump power or lower repetition rates will lead to higher intracavity net-gain, which in turn will lead to higher peak power pulses. In comparison with our previous study [8], both the maximum average power and a slope efficiency values are similar (at the same operating conditions). Here, the highest slope efficiency is 40 % in the CW case and the lowest is 23 % in pulsed case at 10-kHz repetition rate.…”

“…To allow proper temporal synchronization, Q-switching in coherently combined lasers needs to be simultaneous for all channels; this goal can be achieved with three different techniques. First, the beams from all combined laser channels can be brought together without overlapping, such that they are assembled into one closely packed group (in free space) that is passed through a single Q-switch [8]. Although this technique is relatively easy to perform, the limited clear aperture of the Q-switches limits the number of beams that can be clustered together and passed through a given Q-switch.…”

High-power ns-pulse fiber laser sources for remote sensors

“…Because of SF, scaling peak power far beyond few MW is likely achievable only outside of fibers. One approach is to combine pulse-synchronized fiber laser sources either spectrally or coherently [38,[43][44][45]. Another approach is to use the fiber-based MOPA for seeding a single or series of bulk solid-state amplifiers (e.g.…”

Overcoming peak-power limitations of fiber lasers

“…We recently reported on the experimental investigation of high-peak-power, passiveinterferometric coherent combining of two PCF laser channels within a common Q-switched cavity: see Figure 1. 11,12 We formed the resonator using two commercially available active fibers (55cm-long, double-clad, ytterbium-doped, single-mode, rod-type PCFs), an acousto-optic Q-switch, a common highly reflective broadband rear mirror, a partially reflective output coupler (OC) with 4% reflectivity, and two 30W fiber-coupled pump diodes. Furthermore, to use the same Q-switch for both channels, we employed a right-angle, highly reflective broadbandcoated prism to bring the two beams close to each other without any overlap between them.…”