Showing papers by "Andrius Baltuška published in 2006"

Parametric amplification of few-cycle carrier-envelope phase-stable pulses at 2.1 μm

Abstract: We demonstrate an optical parametric chirped-pulse amplifier producing infrared 20 fs (3-optical-cycle) pulses with a stable carrier-envelope phase. The amplifier is seeded with self-phase-stabilized pulses obtained by optical rectification of the output of an ultrabroadband Ti:sapphire oscillator. Energies of -80 microJ with a well-suppressed background of parametric superfluorescence and up to 400 microJ with a superfluorescence background are obtained from a two-stage parametric amplifier based on periodically poled LiNbO3 and LiTaO3 crystals. The parametric amplifier is pumped by an optically synchronized 1 kHz, 30 ps, 1053 nm Nd:YLF amplifier seeded by the same Ti:sapphire oscillator.

Extending the supercontinuum spectrum down to 200 nm with few-cycle pulses

Abstract: By focusing 805 nm pulses of low energy (0.2-1 mJ) into atmospheric-pressure argon, a supercontinuum is generated with a short- wavelength cutoff of 640, 250 and 210 nm for initial pulse durations of 45, 10 and 6 fs, respectively. It is shown numerically that the large shift of the UV cutoff and many features of the spectrum are caused by terms beyond the slowly-varying- envelope approximation (SVEA). Their effect on pulse compression and filament length is also discussed.

Seeding of an eleven femtosecond optical parametric chirped pulse amplifier and its Nd/sup 3+/ picosecond pump laser from a single broadband Ti:Sapphire oscillator

Abstract: We demonstrate direct simultaneous seeding of a few-cycle optical parametric chirped pulse amplifier (OPCPA) in the 700-1000-nm spectral range, and of a Nd:YLF amplifier emitting 30-ps pulses at 1053 nm by use of a chirped-mirror 6-fs Ti:sapphire oscillator. This approach of employing a single master oscillator to drive two power amplifiers simplifies the pump laser design and is applied to eliminate the timing jitter between the seed and the pump pulses in the OPCPA chain. We show that 10 mJ fundamental picosecond pump pulses with the intensity contrast in excess of 10/sup 4/ relative to the nanosecond Q-switched background can be achieved with the seed intensity available in the edge of the oscillator spectrum around 1053 nm. Cross-correlation measurements between the picosecond pump and femtosecond oscillator pulses reveal no traceable timing jitter between the OPCPA pump and seed pulses. The estimated long-term jitter of 0.3 ps is attributed to the thermal expansion of the cavity of the Nd:YLF regenerative amplifier.

Widely tunable soliton frequency shifting of few-cycle laser pulses

Abstract: Photonic-crystal fibers are employed to demonstrate widely tunable frequency down-conversion of unamplified $6\text{\ensuremath{-}}\mathrm{fs}$ Ti:sapphire laser pulses through the soliton self-frequency shift induced by the Raman effect. Wavelength shifts as large as $500\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ are achieved for input few-cycle pulses with broadband spectra centered at approximately $820\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. The central wavelength of the redshifted output of a photonic-crystal fiber is smoothly tuned from the low-frequency edge in the spectrum of the $6\text{\ensuremath{-}}\mathrm{fs}$ Ti:sapphire laser pulse up to $1.35\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{m}$ by varying the input energy in the fundamental mode of the fiber.

Diffraction-arrested soliton self-frequency shift of few-cycle laser pulses in a photonic-crystal fiber.

Abstract: The balance between diffraction and index-step guiding in photonic-crystal fibers is controlled by modifying the fiber structure, leading to different wavelength dependences of the effective mode area ${S}_{\mathrm{eff}}(\ensuremath{\lambda})$ and providing a mechanism to control nonlinear-optical phenomena. In optical fibers with a steep ${S}_{\mathrm{eff}}(\ensuremath{\lambda})$ profile, the guided mode of the light field tends to become much less compact with an increase in radiation wavelength, slowing down the Raman-induced soliton self-frequency shift of an ultrashort laser pulse. A $100\text{\ensuremath{-}}\mathrm{nm}$ reduction of the soliton self-frequency shift is demonstrated for $6\text{\ensuremath{-}}\mathrm{fs}$ input laser pulses.

Parametric amplification of ultra-short light pulses

Abstract: The invention relates to a method and a device for parametric amplification of ultra-short light pulses, comprising generating seed pulses and pump pulses, and generating signal pulses by an interaction of the seed pulses and the pump pulses in an optical-parametric amplifier, and further comprising generating clock pulses by frequency-shifting a fraction of the seed pulses with a frequency shifter device and seeding an optical amplifier device with the clock pulses for generating the pump pulses.

Attosecond pulse production and orbital tomography with orthogonally polarized two-color few-cycle pulses

Abstract: We theoretically investigate the potential of orthogonally polarized two-color few-cycle pulses for important applications in attosecond physics, such as attosecond pulse production and orbital tomography.

Few-cycle chirped-pulse parametric amplification

Abstract: We review progress in the development of kilohertz-repetition-rate few-cycle optical parametric chirped pulse amplifiers (OPCPA) in the near-IR (700-1000 nm) and IR (1700-2800 nm) spectral ranges. These sources hold promise for applications in extreme nonlinear optics and attosecond physics.