Passive mode locking of a continuous-wave energy-transfer dye laser operating in the near infrared around 750 nm

The passive mode locking of an argon-ion-pumped energy-transfer cw dye laser operating in the near infrared is reported. The dyes 1,1'-diethyl-4,4'-carbocyanine iodide and 1,1'-diethyl-2,2' -dicarbocyanine iodide were used separately to mode lock a gain medium comprising the dyes DCM and Rhodamine 700. Subpicosecond pulses were generated from 732 to 761 nm in a simple linear cavity, and pulses as short as 110 fsec were obtained from a colliding pulse mode-locked ring cavity that was tuned between 742 and 754 nm.