Double-crystal Scheme Research Articles

Actively Q-switched Nd:YLF laser emitting at 908 nm

An actively Q-switched quasi-three-level Nd:YLF laser emitting at 908 nm, for the first time to our knowledge, was demonstrated. A RTP double-crystal scheme was used to realize electro-optical Q-switcher, and a L-shaped cavity structure was designed to suppress parasitic oscillation at 1047 nm. An 806 nm laser diode was used as the pump source with about 480 μs pulse width. With 46.4 mJ pump pulse energy input at repetition rate of 100 Hz, maximum output pulse energies of 0.84 mJ and 0.73 mJ were obtained with output transmissions of 6.5% and 11%, respectively. The corresponding peak pulse powers were up to 14.3 kW and 12.1 kW, and the output pulse widths were 58.6 ns and 60.3 ns. The central laser wavelengths were both at 908.3 nm with spectral bandwidth of over 0.7 nm.

A double-crystal scheme with full compensation of the Migdall effect

The double-crystal scheme for polarization-entangled photon pairs generation is presented. The negative impact of the Migdall effect on the polarization entanglement is fully compensated in the scheme. The theory for quantifying of entanglement decrease as the action of the Migdall effect is formulated.

A SPDC-Based Source of Entangled Photons and its Characterization

We present a short review of development and applications of single and biphoton sources. The main emphasis is on spontaneous parametric down-conversion (SPDC) sources capable of producing timecorrelated photon pairs. We also present a SPDC source of photon pairs at 1,064 nm pumped by a cw 532 nm laser. We consider the fundamental principles of quantum tomography and present results of characterization (entanglement and purity) of biphoton quantum states produced by this source. Additionally, we discuss some aspects of quantum entanglement suppression caused by the Migdall effect in a double-crystal scheme.

Nontrivial role of the resolution function in the formation of double-crystal X-ray rocking curves

A theoretical analysis of the shape of the resolution function of an X-ray diffractometer in the double-crystal nondispersive scheme for measuring rocking curves has been performed. It is shown that this function, along with the strong narrow central line (corresponding to the characteristic line to which the collimator crystal and slits in the experimental scheme are tuned) always contains an additional weak satellite, corresponding to the neighboring characteristic line. This feature manifests itself in experimental curves as an additional pseudopeak, whose intensity is comparable with the corresponding diffraction scattering intensity from a sample in the fundamental characteristic line, and whose shape and exact position are set by the resolution function in a specific experimental scheme. It is shown that the exact allowance for the angular and spectral distribution of incident radiation in the double-crystal scheme makes it possible to precisely determine the parameters of the structures studied.

Reply to Comment on "Generation of 10^11 contrast 50 TW laser pulses"

We show that the Comment of Albert et al. [Opt. Lett.31, 2990 (2006)], although being only marginally relevant to the content of the original paper [Opt. Lett.31, 1456 (2006)], misinterprets our results and leads to a wrong conclusion: that the rotation of the second crystal in the double-crystal scheme is unimportant. On the contrary, it follows from the Comment itself as well as from our experiment that the crystal rotation is the main factor in improving the efficiency.