Ultra-high power single mode green fiber laser operating in continuous wave and quasi-continuous wave regimes

A high power single mode (SM) fiber laser operating in a Green spectral range comprising:

• a quasi-continuous wave (QCW) laser source operating with a duty cycle between about 2 and 100% with the 100% duty cycle corresponding to a continuous-wave (CW) mode, the QCW laser source configured with:
• a single frequency (SF) single mode (SM) linearly polarized (LP) seed operative to generate SF SM LP light with a linewidth lower than 1 MHz at a fundamental wavelength in one (1) micrometer spectral range, and
• at least one ytterbium (Yb) doped fiber amplifier receiving and amplifying the SF SM LP light at the fundamental wavelength while maintaining the linewidth narrower than 1 MHz;
• a nonlinear optical frequency converter configured to convert the amplified SF SM LP light in a single-pass second-harmonic generator (SHG) to output SM Green light, wherein the SM fiber laser operates with a wall plug efficiency between 15% and 30% in a 510-540 nm wavelength range and an average power level of from about 50 watts (W) up to a 2 kW level;
• and
• a phase modulator or amplitude modulator coupled between the seed and the at least one Yb doped fiber amplifier and operative to homogeneously broaden the single frequency linewidth of the SF SM LP light from the seed to a linewidth between 10 to 40 GHz.