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Hollow-core photonic-crystal fibers are shown to substantially enhance four-wave mixing (FWM) of laser pulses in a gas filling the fiber core. Picosecond pulses of Nd:YAG fundamental radiation and its second harmonic are used to generate a signal at the frequency of the third harmonic by the FWM process 3omega = 2omega + 2omega - omega. The efficiency(More)
We demonstrate a robust, all-solid-state approach for the generation of microjoule subcycle pulses in the midinfrared through a cascade of carefully optimized parametric-amplification, difference-frequency-generation, spectral-broadening, and chirp-compensation stages. This method of subcycle waveform generation becomes possible due to an unusual,(More)
Strongly coupled nonlinear spatiotemporal dynamics of ultrashort mid-infrared pulses undergoing self-focusing simultaneously with soliton self-compression in an anomalously dispersive, highly nonlinear solid semiconductor is shown to enable the generation of multioctave supercontinua with spectra spanning the entire mid-infrared range and compressible to(More)
A physical scenario whereby freely propagating mid-infrared pulses can be compressed to pulse widths close to the field cycle is identified. Generation of tunable few-cycle pulses in the wavelength range from 4.2 to 6.8 μm is demonstrated at a 1-kHz repetition rate through self-focusing-assisted spectral broadening in a normally dispersive, highly nonlinear(More)
We demonstrate a scanning fiber-optic probe for magnetic-field imaging where nitrogen-vacancy (NV) centers are coupled to an optical fiber integrated with a two-wire microwave transmission line. The electron spin of NV centers in a diamond microcrystal attached to the tip of the fiber probe is manipulated by a frequency-modulated microwave field and is(More)
Laser filamentation is understood to be self-channeling of intense ultrashort laser pulses achieved when the self-focusing because of the Kerr nonlinearity is balanced by ionization-induced defocusing. Here, we show that, right behind the ionized region of a laser filament, ultrashort laser pulses can couple into a much longer light channel, where a stable(More)
Coherent anti-Stokes Raman scattering (CARS) is used to measure the amplitude, the dephasing lifetime, and parameters of optical nonlinearities of optical phonons in a synthetic diamond film. A compact CARS apparatus demonstrated in this work relies on the use of an unamplified 70 fs 340 mW Cr:forsterite laser output and photonic-crystal fibers optimized(More)
A high-energy supercontinuum spanning 4.7 octaves, from 250 to 6500 nm, is generated using a 0.3-TW, 3.9-μm output of a mid-infrared optical parametric chirped-pulse amplifier as a driver inducing a laser filament in the air. The high-frequency wing of the supercontinuum spectrum is enhanced by odd-order optical harmonics of the mid-infrared driver. Optical(More)
We show that sequences of femtosecond laser pulses can control the rotational Raman response of a gas mixture, giving rise to a tunable manifold of echo recurrences in the retarded nonlinear-optical response of the gas. Tailored phase masks for high-intensity ultrashort laser pulses are experimentally demonstrated using molecular rotations in the gas phase(More)
A mode-locked chromium forsterite laser with output power in excess of 0.7 W, a central wavelength of 1.25 μm, a pulse repetition rate of 29 MHz, and an output pulse-width-tunable from 40 to 200 fs is demonstrated. The dynamics behind the buildup of ultrashort light pulses in this laser is shown to involve spectral and temporal breathing due to the(More)