We demonstrate complete control over the polarization, phase and amplitude state of an ultrafast laser pulse using a single, linear spatial light modulator. Characterization and applications of vector pulse shaping will also be discussed.

Intense 5.1-fs pulses were generated through filamentation in argon while maintaining the CEO phase. The benefits to CEO phase control of using the generated octave-spanning spectrum for single shot f-2f spectral interferometry are also presented.

Intense 5.1 fs CEO (carrier envelope offset) phase stable pulses were generated through two-fold filamentation in a noble gas at atmospheric pressure. The preservation of the CEO phase during the filamentation process was investigated. We show that generating these short pulses using filaments is not detrimental for the CEO phase stabilization, and that the more than one octave-spanning spectrum intrinsically generated by the process is feasible, and offers certain benefits, for direct use in single shot f-2f spectral interferometry.

Intense 5.1-fs pulses were generated through filamentation in argon. The CEO (carrier envelope offset) phase control is investigated of using the intense, octave-spanning spectrum generated during this process, directly for single shot f-2f spectral interferometry.

We have enhanced extreme ultraviolet (XUV) harmonics around 90 eV in He using a combination of vacuum ultraviolet harmonics, generated in a Xe capillary, and the strong infrared (IR) laser pulse. With no changes in the IR input energy or the configuration of the He target, the collinearly focused combination of the two fields changed the spectral properties and increased the yield of the XUV harmonics compared to those generated with the IR field alone.

We theoretically predict and experimentally confirm that enhancement of high-order harmonic generation is possible by combining an attosecond pulse train with an IR driving laser. This combination replaces the disadvantages of tunnel ionization with single-photon ionization and permits the manipulation of the time-frequency properties of high-order harmonic generation already at the single-atom level.

We present a first experiment on attosecond pulse train (APT) assisted high-order harmonic generation, where the APT triggers the release of the electron into the continuum, which leads to an enhancement of harmonic yield.

We report the production of frequency-sheared high harmonics in argon by control of the envelope and chirp of the electric field of the femtosecond driving laser pulse. Using the classic three-step model of high-harmonic generation, we established a direct link between the properties of the harmonics and the fully characterized driving pulses. A simulation of the single-atom response in the strong-field approximation confirms the simple picture and shows good agreement with the experimental results.

We demonstrate the presewation of the camer-envelope offset (CEO) phase in chirpedpulse optical parametric amplification. The amplifier yields 77913, 17.3-ts pulses directly from a 1.7-d, 11.6-fs Ti:sapphire oscillator seed, in agreement with full numerical simulations. B 2004 optical Society of America OClS codes: 199.4970 (Parametric oscillators and amplifiers), 320.7710 (Ultrafast nonlinear optics) We present experimental confirmation of CEO phase preservation in chirped pulse optical parametric amplification (CPOPA) [I] of 1.7-nJ, 11.6-fs pulses from a CEO-phase-stabilized Ti:sapphire oscillator, which are amplified and recompressed to 17.3 fs with the phase lock preserved. The seed pulses from the oscillator were stretched by bulk dispersion, amplified in a single pass through a 3-mm long BBO crystal (0 = 29.2") with a single-pass gain of 8.5x104, and recompressed with a prism compressor. The amplified pulse energy was 85 pJ (77 rcJ compressed). Figure la shows the measured oscillator (dashed line) and recompressed (solid) pulses. To verify the CEO phase preservation experimentally, we recorded the spectral interference fringes in anf-to-2f interferometer [2] as shown in Fig. Ih. The appearance and persistence of interference fringes (lower half) confirm that the amplified pulses maintain the CEO phase lock. With the oscillator CEO phase lock switched off, the fringes wash out (upper half). Phase preservation is assured by the coupled wave equations governing the OPA process but has not, to our knowledge, been previously demonstrated experimentally. It is crucial for applications such as strong-field physics, where CPOPAs are emerging as attractive alternatives to conventional amplifier systems for their large gains, broad gain bandwidths, and eliminated thermal loading. Previous demonstrations of CPOPA have used high energy, nanosecond pulses, but direct amplification of fs oscillator pulses to sub-millijoule levels has not been reported at kHz repetition frequencies due to the absence of adequate pump sources. For this initial proof-of-principle experiment, we used a frequency-doubled modified regenerative amplifier (Legend, Positive Light) as a pump source, which yielded near-transform-limited 2.3-ps pulses at 400 nm with a I-kHz repetition rate. Numerical simulations of the system, including numerical propagation of the seed pulse measured by SPIDER through all optical components, full 3D modeling of the three-wave mixing process, and ray-tracing through the pulse compressor, predicted recompression to 12.7 fs and amplification to 97 pJ for 1 mJ pump, excluding system losses. The measured values are in close agreement with the model.

Phase-stabilized 12-fs, 1-nJ pulses from a commercial Ti:sapphire oscillator are directly amplified in a chirped-pulse optical parametric amplifier and recompressed to yield near-transform-limited 17.3-fs pulses. The amplification process is demonstrated to be phase preserving and leads to 85-microJ, carrier-envelope-offset phase-locked pulses at 1 kHz for 0.9 mJ of pump, corresponding to a single-pass gain of 8.5 x 10(4).

We present a design for phase-locked chirped pulse optical parametric amplification of ultra-short pulses based on Ti:sapphire. A realistic description is given by measuring the oscillator pulse (11.6 fs, 4 nJ) with SPIDER and numerically propagating it through the whole chirped pulse amplification system. The interaction is modeled with a full three-dimensional code and compression is ray-trace optimized to yield 12.7-fs, 98-μJ pulses with 1 mJ of pump energy. The design is scalable in energy (e.g. 1 mJ with 10-mJ pump) and is exclusively based on commercially available components .

First experimental results from ultrabroadband chirped-pulse optical parametric amplification of 1.7 nJ, 12-fs pulses show amplified flat spectra (160 nm) with energies of 50 alphaJ, leading to preliminarily compressed pulses of 28 fs duration

We propose a BBO-based chirped-pulse optical parametric amplifier employing an angularly dispersed signal beam to yield a full-octave gain bandwidth, sufficient for the direct amplification of sub-10-fs pulses. Numerical simulations show that this power-scalable amplifier configuration has a small-signal gain of 10(7) at a pumping intensity of 45 GW/cm(2). The additional phase-matching flexibility compared to alternative configurations permits the suppression of parasitic second harmonic generation of the signal beam.

We report a novel architecture for power scaling of near-diffraction-limited, single-frequency lasers. In a first demonstration, we have generated 20 W single-frequency output from a MOPA based on a large core, double-clad, Yb fiber preamplifier and self-imaging Nd: YAG waveguide power amplifier.

A singly resonant, single-axial-mode, optical parametric oscillator (OPO) based on periodically poled KTiOPO4 (PPKTP) is reported. Signal (1.68 micron) and idler (2.90 micron) optical bandwidths have been narrowed to <400 MHz by use of a diffraction grating at grazing incidence. The OPO generates 370 microJ of signal radiation when pumped by 3.1 mJ of 1.064-micron radiation. We implemented a single-pass PPKTP amplifier to yield 2.15-mJ signal and 1.17-mJ idler radiation without broadening the spectral bandwidths.

Single axial mode operation (<200 MHz optical bandwidth) of a high repetition rate periodically poled lithium niobate optical parametric oscillator (OPO) has been obtained at signal wavelengths between 1.46 μm and 1.64 μm. OPO signal slope efficiencies of 35% have been measured for repetition rates of 5–20 kHz. Single mode operation required spectral narrowing of both the pump laser and the OPO. A simple technique of prelase Q-switching was implemented to reduce the optical bandwidth of the cw diode-pumped Nd:YAG pump laser to <1 GHz. A single intracavity étalon was then sufficient to ensure single frequency oscillation of the OPO signal. The OPO output was stable with a smooth spatial profile and an M2 value of 1.3.

We report optical parametric oscillators (OPO) based on periodically poled KTiOPO4, pumped by nanosecond 532 nm pulses, and capable of delivering 5 mJ pulse energy. The OPO output could be tuned from 756–771 nm (signal) and 1.72–1.80 µm (idler), with peak efficiencies of up to 37% (signal) and 8% (idler). Monolithic OPO oscillation and single frequency operation with an instrument limited optical bandwidth of 250 MHz are also demonstrated.

Summary form only. Periodically poled lithium niobate (PPLN) has recently emerged as an attractive material for high gain, low pulse energy OPOs for spectroscopy and DIAL remote sensing applications. In many cases, narrowband or single mode operation is required, but pulsed ns OPOs exhibit broad free-running optical bandwidths, especially when operating near degeneracy. We report on OPOs in a grazing incidence (GI) configuration. These devices generate efficient, single axial mode, near TEM/sub 00/ output and offer a number of advantages over recently reported single mode PPLN OPOs incorporating injection seeding or intracavity cavity etalons. The GI OPO is a simple, compact device capable of emitting single mode radiation throughout the full tuning range of the OPO. It dispenses with the cost, complexity and limited tuning of seeded systems. Intracavity cavity etalons tend to preclude simultaneous signal and idler output, as well as single mode operation close to degeneracy. In the GI cavity, high loss-which limits the performance of KTP and BBO GI OPO-is offset by the substantially higher gain in PPLN.

We have demonstrated a simple grazing-incidence optical parametric oscillator (OPO) based on periodically poled lithium niobate (PPLN) capable of generating single-mode visible (619–640 nm) and infrared (3.16–3.77 μm) radiation. The single-mode (<400 MHz bandwidth) signal output energy of the OPO was limited to 10 μJ due to residual idler reflections supporting a monolithic OPO within the PPLN crystal. A perylene red doped poly(methyl methacrylate) disc was used to amplify the signal wavelength up to 114 μJ in a single pass without broadening the optical bandwidth.

We report single longitudinal mode operation of a pulsed Nd:YAG pumped periodically poled lithium niobate optical parametric oscillator (OPO). The combination of a prism and an etalon provides both coarse and fine spectral resolution, thereby eliminating parasitic resonant oscillation of cascaded signal wavelengths, idler wavelengths, and adjacent longitudinal modes of the signal field. Optical bandwidths of less than 300 MHz have been obtained at signal wavelengths between 1.47 and 1.59 mum. In comparison with broadband operation, the single-mode OPO shows only a 9% reduction in pump depletion with a negligible reduction in extraction efficiency.