Mid-infrared second-harmonic generation in chalcogenide photonic crystal fiber

This study theoretically investigated a feasible modal phase-matching second-harmonic generation (SHG) in chalcogenide photonic crystal fiber. SHG is a technique that enables the acquisition of the mid-infrared resource at 5.3 µm with the use of a 10.6 µm commercial laser. The phase-matching condition between two low-order modes can be realized simply by modifying the air hole size and lattice pitch in the designed photonic crystal fiber. Numerical results showed that the confinement loss of the second-harmonic wave was 4.15×10−4 dB/m at 5.3 µm, and the effective phase-matched fiber length reached as long as 6.382 m.