Switching of 800 nm femtosecond laser pulses using a compact PMN-PT modulator

A voltage-controlled birefringent cell based on ceramic PMN-PT material is used to enable fast intensity modulation of femtosecond laser pulses in the 800 nm wavelength window. The birefringent cell based on a PMN-PT compound has comparatively high electro-optic response, allowing for a short interaction length of 3 mm and thus very small size, low attenuation of 0.16 dB, and negligible broadening for 100 fs optical pulses. As an application example, agile wavelength tuning of optical pulses is demonstrated using the soliton self-frequency shift in a photonic crystal fiber. By dynamically controlling the optical power into the fiber, this system switches the wavelength of 100 fs pulses from 900 nm to beyond 1120 nm with less than 5 μs time. In addition, a feedback system stabilizes the wavelength drift against external conditions resulting in high wavelength stability.