Compression of femtosecond pulses in a wide wavelength range using a large-mode-area tapered fiber

We report the design of a tapered fiber that can be used for the compression of pulses at different central wavelengths. The proposed fiber is a three-layer W-type large-mode-area fiber, which has been tapered to transform the mode area from 1700 mu m(2) to 900 mu m(2). We determine the exact length of the maximum pulse compression and numerically demonstrate the compression of a 250 fs, 100 kW peak power input pulse to 15 fs, 850 kW at 1.55 mu m wavelength and compression of 250 fs, 120 kW peak power input pulses to 28 fs, 700 kW and to 46 fs, 500 kW at 1.8 mu m and 2 mu m wavelengths, respectively. Such a fiber can find wide ranging applications, including in communication, spectroscopy and medicine.