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This paper summarizes the generation of sub-single-cycle infrared (IR) pulses through a laser filament and the detailed properties of the generated pulses. The fundamental ($\omega _1$ ) and second harmonic ($\omega _2$) of 30-fs Ti:sapphire amplifier output were focused into nitrogen gas and produced phase-stable broadband IR pulses ($\omega _0$) by four-wave difference frequency generation ($\omega _1 + \omega _1 - \omega _2 \rightarrow \omega _0$...
We demonstrate an ultrastable Yb:fiber amplifier delivering 145 fs pulses with 6 μJ energy at 10 MHz repetition rate. The Er:fiber seed laser provides inherently synchronized broadband continua whose power is boosted via optical parametric amplification.
Using shaped pulses and nonlinear optics, we have experimentally demonstrated the demultiplexing of a train of polarization-encoded single photons through time-to-frequency conversion. We have shown this technique to preserve polarization entanglement with a partner photon.
We demonstrate a broadband parametric amplifier at 6 μm driven by a femtosecond 2.1-μm Ho:YAG chirped-pulse amplifier. The scheme offers an all-in-one solution for seeding, pumping and CEP stabilization of few-cycle pulses in ZnGeP2 and similar mid-IR crystals.
We combine surface-enhanced infrared absorption and a high brilliance optical parametric light source to enable ultra-sensitive and fast Fourier-transform infrared spectroscopy of only 10 000 molecules; inaccessible with conventional thermal light sources or synchrotron radiation.
We investigate nonlinear diffraction in orientation-patterned semiconductors and identify Čerenkov second harmonic generation in a transverse geometry of interaction. Čerenkov second harmonic allows nondestructive 3D visualization of the internal structure of orientation-patterned semiconductor.
Spectral fringes in the second harmonic of fs pulses under strong phase- and group-velocity mismatch are used to evaluate the refractive index of SrB4O7 down to 160 nm, essential for random quasi-phase-matching in the VUV.
We demonstrated the generation of broadband 800nm laser pulse with a BiB3O6 based OPA followed by a SHG process. The achieved pulses are with spectrum of 53.3nm (FWHM) and pulse width of 18.6fs.
An ideal freestanding graphene in air is centrosymmetric in three dimensions, and its optical second harmonic generation is inhibited. However, we found strong second harmonic generation from suspended grapheme sheets, and attributed this observation to curved sheet in the long range.
Time dependent second harmonic optical signals were measured across silicon-on-insulator (SOI) wafer coupons contaminated by Cu-63 ion implanted into the buried oxide (BOX) and near the SOI/BOX and BOX/Bulk interfaces. Average signals after 1 second of exposure for all spatial points were compared between wafers and used to differentiate contamination levels post ion-implantation.
The generation of optical frequency combs in microresonators will be reviewed, enabling on-chip integration of combs with GHz repetition rates. Recent experiments that demonstrate the generation of solitons are described and the application of these combs for coherent communication reviewed.
We demonstrate parametric frequency conversion with large frequency shift up to 30 THz and super continuum generation in the mid-infrared by pumping polymer-coated chalcogenide optical microfibers with a femto second optical parametric oscillator.
We present the development of a mid-infrared (IR) frequency comb based on a singly-resonant optical parametric oscillator (OPO) for signal. An average idler output power of 110mW was achieved at the idler wavelength of 3.5 μm by pumping with a 1040nm ytterbium-fiber mode-locked laser with 2.2W output power. The OPO-based mid-IR comb can be applied to the generation of a high-power, high-repetition-rate...
We present the carrier-envelope phase dependent high-order harmonic generation in argon at 200 kHz repetition rate using ultra-short laser pulses from an optical parametric chirped pulse amplifier.
We present a detailed investigation of third and fifth harmonics generation with 20 fs pulses at 2 µm in CaF2 crystal, revealing a negligible contribution of higher-order Kerr terms up to intensities of 15 TW/cm2.
Noncollinear second-harmonic generation is induced by a volume grating which is directly written into a lithium niobate wafer by femtosecond laser pulses. The efficiency can be increased by Bragg matching of the fundamental wave.
Using modified uni-travelling carrier photodiodes that exhibit high linearity at high photocurrent we have generated a 10 GHz microwave carrier via optical frequency division with sub 500 attosecond absolute timing jitter (1Hz – 10 MHz).
Various predesigned terahertz spectra can be generated via optical rectification of laser pulses in aperiodically poled crystals. The opportunity to manage the terahertz spectrum via the crystal domain structure is stored when the femtosecond transform-limited optical pulses are replaced by the non-transform-limited pulses of the same spectral bandwidth.
Ultra-broadband laser frequency combs operating at multi-gigahertz repetition rate are important for applications in frequency metrology, as well as time-resolved and frequency-domain spectroscopy. A compact Ti:Sapphire laser (depicted in Fig. 1(a)) is a promising candidate for implementing such a frequency comb. Recently a 10 GHz self-referenced Ti:Sapphire was shown to provide an ultra-broadband...
Ultrashort pulses are capable of processing practically any material with a negligible heat affected zone [1]. For productive industrial applications a pulse duration of about 5 ps is a well established compromise between being faster than the electron-phonon interaction time of the material and being long enough to suppress detrimental effects such as nonlinear interaction with the ablated plasma...
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