Search results for "pump"
showing 10 items of 471 documents
High-Spatial-Resolution Monitoring of Strong Magnetic Field using Rb vapor Nanometric-Thin Cell
2011
We have implemented the so-called $\lambda$-Zeeman technique (LZT) to investigate individual hyperfine transitions between Zeeman sublevels of the Rb atoms in a strong external magnetic field $B$ in the range of $2500 - 5000$ G (recently it was established that LZT is very convenient for the range of $10 - 2500$ G). Atoms are confined in a nanometric thin cell (NTC) with the thickness $L = \lambda$, where $\lambda$ is the resonant wavelength 794 nm for Rb $D_1$ line. Narrow velocity selective optical pumping (VSOP) resonances in the transmission spectrum of the NTC are split into several components in a magnetic field with the frequency positions and transition probabilities depending on th…
Electromagnetically Induced Transparency and optical pumping processes formed in Cs sub-micron thin cell
2012
Abstract The Electromagnetically Induced Transparency (EIT) effect in a Λ -system formed by Cs atoms (6 S 1/2 − 6 P 3/2 − 6 S 1/2 ) confined in an extremely thin cell (ETC) (atomic column thickness L varies in the range of 800 nm –3 µm is studied both experimentally and theoretically. It is demonstrated that when the coupling laser frequency is in exact resonance with the corresponding atomic transition, the EIT resonance parameters weakly depend on L , which allows us to detect the effect at L = λ = 852 nm. EIT process reveals a striking peculiarity in case of the coupling laser detuned by Δ from the atomic transition, namely the width of the EIT resonance rapidly increases upon an in…
Design and operation of CMOS-compatible electron pumps fabricated with optical lithography
2017
We report CMOS-compatible quantized current sources (electron pumps) fabricated with nanowires (NWs) on 300mm SOI wafers. Unlike other Al, GaAs or Si based metallic or semiconductor pumps, the fabrication does not rely on electron-beam lithography. The structure consists of two gates in series on the nanowire and the only difference with the SOI nanowire process lies in long (40nm) nitride spacers. As a result a single, silicide island gets isolated between the gates and transport is dominated by Coulomb blockade at cryogenic temperatures thanks to the small size and therefore capacitance of this island. Operation and performances comparable to devices fabricated using e-beam lithography is…
Double-pulse single-beam grazing-incidence pumping
2011
The paper reports on the optimization of a table-top nickel-like molybdenum transient collisionally excited soft x-ray laser (SXRL) at 18.9 nm, performed by double-pulse single beam grazing incidence pumping (DGRIP) [1]. This scheme allows for the first time the full control of the pump laser parameters including the pre-pulse duration, optimally generating the SXRL amplifier under grazing incidence. The single beam geometry of collinear double-pulse propagation guarantees the ideal overlap of the pre- and main pulse from shot to shot, resulting in a more efficient, highly stable SXRL output. SXRL energies up to 2.2 µJ are obtained with a total pump energy less than 1 J for several hours at…
50 mJ/30 ns FTIR Q-switched diode-pumped Er:Yb:glass 1.54 μm laser
2001
Abstract 50 mJ Q-switched output at 30 ns pulse duration was demonstrated with a transversely diode-pumped bulk Er 3+ :Yb 3+ :glass 1.54 μm laser system of uncomplicated and compact design, using a piezoelectrically driven FTIR shutter. In long-pulse operation, 360 mJ output was obtained for 2.65 J incident optical pump energy. Maximum optical slope efficiencies of 20.5% and 5.4% were measured in long-pulse and Q-switched operation, respectively. Optimum Q-switch timing was studied taking into account the Yb 3+ →Er 3+ energy transfer process and was correlated with free-running delay parameters.
Efficient pulsed 946-nm laser emission from Nd:YAG pumped by a titanium-doped sapphire laser
2008
Efficient pulsed room-temperature laser emission at 946 nm is obtained from a Nd:YAG rod pumped by a Ti-doped sapphire laser in the free-running mode. Three bonded YAG rods of 3-mm diameter with different Nd concentrations and active lengths were tested. A maximum output energy of 83.5 mJ at 3 Hz was obtained with a slope efficiency of 32.3% in an end-pumping configuration.
Very low instability threshold in a three-level laser model with incoherent optical pumping
1997
Abstract The stability properties of a laser model based on a closed three-level atomic scheme with incoherent optical pumping are studied. Unexpectedly, the instability threshold can be very low approaching the lasing threshold for large unsaturated gain values.
Space-time features of THz emission from optical rectification in sub-wavelength areas
2011
We present our investigation on the THz space-time emission characteristic induced by the non-paraxial generation regime in highly localized THz generation via optical rectification on sub-wavelength areas.
Laser frequency stabilization by magnetically assisted rotation spectroscopy
2011
Abstract We present a method of Doppler-free laser frequency stabilization based on magnetically assisted rotation spectroscopy (MARS) which combines the Doppler-free velocity-selective optical pumping (VSOP) and magnetic rotation spectroscopy. The stabilization is demonstrated for the atomic rubidium transitions at 780 nm. The proposed method is largely independent of stray magnetic fields and does not require any modulation of the laser frequency. Moreover, the discussed method allows one to choose between locking the laser exactly to the line center, or with a magnetically-controlled shift to an arbitrary frequency detuned by up to several natural linewidths. This feature is useful in ma…
On the potential of 914 nm pumping of Nd:YVO4 for laser operation at 1064 nm
2011
1064 nm-Nd :YVO4 lasers were pumped at 808 nm and 914 nm. The comparative study shows that 914 nm-pumping is adapted for cw operation whereas 808 nm-pumping provides higher population inversion interesting for Q-switched operation.