Five-optical-cycle pulse generation in the mid-infrared from an optical parametric oscillator based on a periodically-poled lithium niobate

We describe an optical parametric oscillator based on aperiodically poled lithium niobate that generates nearly transform-limited 53-fs duration pulses at a center wavelength of 3 mu m, corresponding to only 5 optical cycles. Results are presented illustrating the effect of pump- and grating-period chirp on the idler pulses, and a configuration capable of producing idler bandwidths in excess of 700 nm is discussed. (C) 2000 Optical Society of America OCIS codes: 190.7110, 190.4410, 190.4970, 190.2620.