Electro-optically tunable optical parametric oscillator based on periodically poled lithium niobate

Quasi phase-matching (QPM) is an attractive technique for optical wavelength conversion applications instead of the conventional birefringent phase matching. An advantage of the QPM is that any interaction within the transparency range of the material can be noncritically phase matched at a specific temperature by using the largest nonlinear optical coefficient. The periodically poled lithium niobate (PPLN) has been extensively used for the quasi phase-matched optical parametric oscillator (QPM-OPO). The effective nonlinear coefficient of the PPLN is 21.6 pm/V and enables one to realize efficient wavelength conversion. Usually the wavelength tuning of the QPM-OPO is achieved by changing the crystal temperature. Although the wide wavelength tuning range is achieved with the temperature tuning, the response is not fast. In this paper we demonstrate the wavelength tuning of the QPM-OPO by the electro-optic effect for fast wavelength tuning.