Passive mode locking in the near infrared

Passive mode locking in the previously uncovered 705-798 nm spectral region has been achieved with a simple flashlamp-pumped dye laser using rhodamine 700 as the active medium with DCI (1, 1'-Diethyl-4, 4'-carbocyanine iodide) and DDCI (1, 1' Diethyl-2, 2'-dicarbocyanine iodide) as saturable absorbers. Pulses having duration in the range 4-7 ps with peak powers up to 10 MW have been produced. Several other saturable absorbers have also been shown to operate successfully in this wavelength range.