Continuous wave optical parametric oscillators as new tool for high resolution spectroscopy

We present a new generation of continuous-wave optical parametric oscillators (cw OPOs) that are particularly well suited for applications in high resolution spectroscopy. Such systems can now provide powerful (10 – 800 mW) coherent radiation over an extremely wide range of wavelengths (550 – 4000 nm). They feature extremely narrow line-widths (< 50 kHz), continuous tunability (several GHz), and good long-term stability (< 100 MHz frequency drift per hour, < 5% power drift per hour). As an typical example for applications of single frequency cw OPOs we present first implementations of Doppler-free molecular spectroscopy (CH4, I2). We also discuss further applications, new developments and future perspectives.