Laser-written waveguides in KTP for broadband Type II second harmonic generation

Femto-second laser writing was used to fabricate waveguides in a z-cut KTP sample with losses below 0.8 dB/cm. They were used for efficient, broad bandwidth, Type II birefringent second harmonic generation to the green. The temperature and wavelength bandwidth were, 28 C ∙ cm and 0.85 nm ∙ cm, respectively.