Abstract

Light pulses of subfemtosecond duration require a spectral bandwidth that is substantially larger than the mode-locking range of any single laser. Recently, an optical Fourier synthesizer has been proposed¹ which can generate light pulses as short as one single optical half-cycle by superposing several light beams with widely spaced equidistant frequencies and actively controlled phases. Just two phase-locked cw laser oscillators are sufficient to generate a comb of 6 equidistant frequencies by second-order sum and difference frequency mixing. Such an elementary pulse synthesizer has a very high repetition rate equal to the frequency spacing. The dispersion of any optical elements in the beam path can be compensated by adjusting the individual phases of the superposed waves.

© 1992 Optical Society of America