B. A. Cumberland

Visible supercontinuum generation in photonic crystal fibers with a 400W continuous wave fiber laser

We demonstrate continuous wave supercontinuum generation extending to the visible spectral region by pumping photonic crystal fibers at 1.07 microm with a 400 W single mode, continuous wave, ytterbium fiber laser. The continuum spans over 1300 nm with average powers up to 50 W and spectral power densities over 50 mW/nm. Numerical modeling and understanding of the physical mechanisms has led us to identify the dominant contribution to the short wavelength extension to be trapping and scattering of dispersive waves by high energy solitons.

29 W High power CW supercontinuum source.

A 29 W CW supercontinuum spanning from 1.06 to 1.67 microm is generated in a short length of PCF with two zero dispersion wavelengths. The continuum has the highest spectral power density, greater than 50 mW/nm up to 1.4 microm, reported to date. The use of a short length of PCF enables the continuum to expand beyond the water loss at 1.4 microm. The dynamics of the continuum evolution are studied experimentally and numerically with close attention given to the effects of the water loss and the second zero dispersion wavelength.

Optical pulse compression in dispersion decreasing photonic crystal fiber.

Improvements to tapered photonic crystal fiber (PCF) fabrication have allowed us to make up to 50 m long PCF tapers with loss as low as 30 dB/km. We discuss the design constraints for tapered PCFs used for adiabatic soliton compression and demonstrate over 15 times compression of pulses from over 830 fs to 55 fs duration at a wavelength of 1.06 lm, an order of magnitude improvement over previous results.

Toward visible cw-pumped supercontinua

We report a 1 mum cw-pumped supercontinuum that extends short of the pump wavelength to 0.65 mum. This is achieved by using a 50 W Yb fiber laser in combination with a photonic crystal fiber with a carefully engineered zero-dispersion wavelength. We show that the short-wavelength generation is due to a combination of four-wave mixing and dispersive wave trapping by solitons. The evolution and limiting factors of the continuum are discussed.

2.1 microm continuous-wave Raman laser in GeO2 fiber.

We report on 33 % efficient generation of the first Stokes in a high concentration GeO2 fiber Raman laser pumped by a 22 W Thulium doped fiber laser. An output power of 4.6 W at 2.105 um is demonstrated.We report 33% efficient generation of the first Stokes in a high-concentration GeO(2) fiber Raman laser pumped by a 22 W thulium-doped fiber laser. An output power of 4.6 W at 2.105 microm is demonstrated.

2.1 um CW Raman Laser in GeO2 Fiber

We report on 33 % efficient generation of the first Stokes in a high concentration GeO2 fiber Raman laser pumped by a 22 W Thulium doped fiber laser. An output power of 4.6 W at 2.105 um is demonstrated.We report 33% efficient generation of the first Stokes in a high-concentration GeO(2) fiber Raman laser pumped by a 22 W thulium-doped fiber laser. An output power of 4.6 W at 2.105 microm is demonstrated.

2 W/nm peak-power all-fiber supercontinuum source and its application to the characterization of periodically poled non-linear crystals

We demonstrate a uniform high spectral brightness and peak power density all-fiber supercontinuum source. The source consists of a nanosecond Ytterbium fiber laser and an optimal length PCF producing a continuum with a peak power density of 2 W/nm and less than 5 dB of spectral variation between 590 and 1500 nm. The Watt level per nm peak power density enables the use of such sources for the characterization of non-linear materials. Application of the source is demonstrated with the characterization of several periodically poled crystals.

Pulse Compression in Dispersion Decreasing Photonic Crystal Fiber

We report dispersion decreasing photonic-crystal-fibers for soliton compression at 1.06 mum. Fibers 15-60 m long with dispersion varying from 40-0 ps.nm-1.km-1 were used to achieve compression ratios of over 15. Pulses of 655 fs were compressed to 43 fs solitons.

Aircore fiber based spectral compression of an all fiber integrated ultrashort pulse source

We report on the spectral compression of an all fiber integrated ultrashort pulse source using both transmission grating pairs and aircore photonic bandgap fiber to provide the required negative chirp.

Short wavelength extension of CW-pumped supercontinuum at 1 micron

We report a CW supercontinuum pumped at 1 mum which extends short of the pump wavelength to 0.6 mum. Four-wave mixing is believed to be a major process for the short wavelength generation.