We demonstrate a new method to fabricate waveguides in KTP. It allows for independently fabrication of the periodically poled grating via coercive field engineering and post-poling waveguide inscription via ion exchange.

We demonstrate a new method to fabricate waveguides in KTP. It allows for independently fabrication of the periodically poled grating via coercive field engineering and post-poling waveguide inscription via ion exchange.

Here, we present a high repetition rate, narrow bandwidth, extreme ultraviolet photon source for time- and angle-resolved photoemission spectroscopy. The narrow bandwidth pulses Δ E = 9, 14, and 18 meV for photon energies h ν = 10.8, 18.1, and 25.3 eV are generated through high harmonic generation using ultra-violet drive pulses with relatively long pulse lengths (461 fs). The high harmonic generation setup employs an annular drive beam in tight focusing geometry at a repetition rate of 250 kHz. Photon energy selection is provided by a series of selectable multilayer bandpass mirrors and thin film filters, thus avoiding any time broadening introduced by single grating monochromators. A two stage optical-parametric amplifier provides < 100 fs tunable pump pulses from 0.65 μm to 9 μm. The narrow bandwidth performance of the light source is demonstrated through angle-resolved photoemission measurements on a series of quantum materials, including high-temperature superconductor Bi-2212, WSe2, and graphene. 

We demonstrate self-compression of 173 fs pulses centered at 1030 nm down to 19.5 fs through electro-optic phase modulation by the phonon-polariton waves generated in a phase-matched intra-pulse difference-frequency mixing.

We demonstrate self-compression of 173 fs pulses centered at 1030 nm down to 19.5 fs through electro-optic phase modulation by the phonon-polariton waves generated in a phase-matched intra-pulse difference-frequency mixing.

We study magnetic traps with very high trap frequencies where the spin is coupled to the motion of the atom. This allows us to investigate how the Born-Oppenheimer approximation fails and how effective magnetic and electric fields appear as the consequence of the non-adiabatic dynamics. The results are based on exact numerical diagonalization of the full Hamiltonian describing the coupling between the internal and external degrees of freedom. The position in energy and the decay rate of the trapping states corresponding to the imaginary part of the resonances of this Hamiltonian are computed using the complex rotation method.

Efficient, diode-pumped high energy femtosecond laser systems around 1 µm based on Yb-gain media are readily commercially available. However, owing to the gain bandwidth limitations, the pulses generated in such lasers are substantially longer than the ones generated in Ti:Sapphire systems. A simple, energy-scalable pulse self-compression scheme for the pulses around 1 µm thus would be of great interest for many applications, including time-resolved pump-probe spectroscopy, high-harmonics generation, etc. The self-phase modulation during nonlinear propagation in filaments in gasses is often employed for pulse self-compression [1,2]. Such schemes typically require rather bulky setups and careful control of group velocity dispersion. Some years ago it has been shown theoretically that Raman-active molecules in gaseous form could be used for mid-infrared pulse compression [3].

Summary form only given. Efficient, diode-pumped high energy femtosecond laser systems around 1 μm based on Yb-gain media are readily commercially available. However, owing to the gain bandwidth limitations, the pulses generated in such lasers are substantially longer than the ones generated in Ti:Sapphire systems. A simple, energy-scalable pulse self-compression scheme for the pulses around 1 μm thus would be of great interest for many applications, including time-resolved pump-probe spectroscopy, high-harmonics generation, etc. The self-phase modulation during nonlinear propagation in filaments in gasses is often employed for pulse self-compression. Such schemes typically require rather bulky setups and careful control of group velocity dispersion. Some years ago it has been shown theoretically that Raman-active molecules in gaseous form could be used for mid-infrared pulse compression. Here we exploit highly-efficient interaction of optical pulses with phonon-polaritons in KTi0PO4 (KTP) for self -compression of fs pulses at 1 gm. The experimental setup consists of a 1030 nm femtosecond pump laser. The pulses were loosely focused by a f=150 mm lens to a beam waist with 1/e 2 radius of 160 gm in a 10 mm -long, 5mm-thick single -domain KTP sample. The pulses were polarized along the c -axis of the crystal. The dependence of the pulse output spectrum as a function of the beam focus position in the crystal is shown, where 300 fs full width at half maximum (FWHIVI) input pulses from a fiber -based system were employed. The broadest spectrum was obtained with the focal plane being located close to the entrance of the crystal. We employed time resolved digital holography to verify the coupling of the optical pulse with phonon-polariton wave during propagation through the crystal. Characterization experiments with 173 fs FWIINI pulses derived from a commercial solid-state laser system were conducted using a custom-built d -scan setup [6]. The setup included chirped mirror...

Here we report of a design and the performance of an optimized micro-fabricated conveyor belt for precise and adiabatic transportation of cold atoms. A theoretical model is presented to determine optimal currents in conductors used for the transportation. We experimentally demonstrate a fast adiabatic transportation of Rubidium (⁸⁷Rb) cold atoms with minimal loss and heating with as few as three conveyor belt conductors. This novel design of a multilayered conveyor belt structure is fabricated in aluminium nitride (AlN) because of its outstanding thermal and electrical properties. This demonstration would pave a way for a compact and portable quantum device required for quantum information processing and sensors, where precise positioning of cold atoms is desirable.