We present a synchronously pumped fiber optical parametric oscillator for coherent anti-Stokes Raman scattering microscopy. Pulses from a 1 μm Yb-doped fiber laser are amplified and frequency converted to 779-808 nm through normal dispersion four-wave mixing in a photonic crystal fiber. The idler frequency is resonant in the oscillator cavity, and we find that bandpass filtering the feedback is essential for stable, narrow-bandwidth output. Experimental results agree quite well with numerical simulations of the device. Transform-limited 2 ps pulses with energy up to 4 nJ can be generated at the signal wavelength. The average power is 180 mW, and the relative-intensity noise is much lower than that of a similar parametric amplifier. High-quality coherent Raman images of mouse tissues recorded with this source are presented.
Lamb, E. S., Lefrancois, S., Ji, M., Wadsworth, W. J., Sunney Xie, X., & Wise, F. W. (2013). Fiber optical parametric oscillator for coherent anti-Stokes Raman scattering microscopy. Optics Letters, 38(20), 4154-4157. https://doi.org/10.1364/OL.38.004154