Abstract: A laser producing high energy ultrashort laser pulses comprises a normal dispersion segment, a gain segment, an anomalous dispersion segment with negligible nonlinearity and an effective saturable absorber arranged to form a laser cavity. Each segment is optically interconnected so that a laser pulse will propagate self-similarly therein. (A pulse that propagates in a self-similar manner is sometimes referred to as a “similariton.”) With this laser the limitations of prior art laser oscillators are avoided. Also provided are means for pumping the gain medium in the laser cavity, and means for extracting laser pulses from the laser cavity. The laser cavity is preferably a ring cavity. Preferably the laser is configured to achieve unidirectional circulation of laser pulses therein. This configuration is scalable to much higher pulse energy than lasers based on soliton-like pulse shaping.

Abstract: A simple and low-cost apparatus amplifies short optical pulses (e.g., in the femtosecond domain) to high pulse energies using energy stored in an enhancement cavity. The enhancement cavity is first filled with pump light from a pump laser; and a signal laser then directs a signal pulse into the cavity, where the signal pulse and pump laser both pass through a non-linear medium for parametric amplification of the signal pulse, wherein energy from the aggregated pump light is transferred to the signal pulse, which then exits the enhancement cavity.

Abstract: An x-ray source that can produce high-brilliance x-rays at a low cost and from a small footprint includes a radiofrequency (RF) photoinjector, an accelerator module (such as a linear superconducting accelerator moducle), a high-power optical laser apparatus, and a passive enhancement cavity. A stream of photons generated by the laser apparatus is accumulated in the enhancement cavity, and an electron stream from the photoinjector are then directed through the enhancement cavity to collide with the photons and generate high-brilliance x-rays via inverse-Compton scattering.

Abstract: A photonic-crystal fiber provides dispersion compensation in a soliton fiber laser. The anomalous dispersion provided by the photonic-crystal fiber permits construction of a femtosecond fiber laser at 1 ?m wavelength without prisms or diffraction gratings. The laser produces ˜100-fs pulses with 1 nJ energy, and is a major step toward environmentally-stable all-fiber devices at 1 ?m.

Abstract: A photonic-crystal fiber provides dispersion compensation in a soliton fiber laser. The anomalous dispersion provided by the photonic-crystal fiber permits construction of a femtosecond fiber laser at 1 &mgr;m wavelength without prisms or diffraction gratings. The laser produces ˜100-fs pulses with 1 nJ energy, and is a major step toward environmentally-stable all-fiber devices at 1 &mgr;m.