Tunable near-infrared optical vortex parametric laser with versatile orbital angular momentum states.

We demonstrate a tunable vortex laser with versatile orbital angular momentum (OAM) states based on a singly resonant optical parametric oscillator formed of a noncritical phase-matching LiBO crystal. The selective generation of a signal (idler) output with three OAMs, including an upconverted (negative) OAM, is achieved simply by appropriate shortening (or extending) of the cavity. The compact cavity configuration also allows for the generation of the signal (idler) output with various OAMs by simply tuning the signal wavelength.

Ultra-widely tunable mid-infrared (6-18 μm) optical vortex source.

We demonstrate the generation of an ultra-widely tunable mid-infrared (6-18 μm) optical vortex output with a moderate pulse energy from a AgGaSe difference frequency generator pumped by an optical vortex parametric oscillator. The handedness of the vortex output can be controlled/selected by swapping the lasing frequencies of the signal and idler outputs and rotating the AgGaSe crystal by 90 deg.

Octave-band tunable optical vortex parametric oscillator.

We developed an octave-band tunable optical vortex laser based on a 532 nm optical vortex pumped optical parametric oscillator with a simple linear-cavity configuration by employing cascaded non-critical phase-matching LiBO crystals. The optical vortex output was tunable from 735 to 1903 nm. For a pump energy of 9 mJ, an optical vortex pulse energy of 0.

Beam propagation of efficient frequency-doubled optical vortices.

Frequency doubling of optical vortices is demonstrated with an optical-optical efficiency exceeding 70%, using a spiral phase plate at a fundamental vortex energy of 10.6 mJ. Beam propagation of the doubled vortex output is also investigated both experimentally and theoretically.

Comparative Transcriptome Analysis of the Less-Dormant Taiwanese Pear and the Dormant Japanese Pear during Winter Season.

The flower bud transcriptome in the less dormant Taiwanese pear 'Hengshanli' and high-chilling requiring Japanese pear strain TH3 subjected to the same chilling exposure time were analyzed during winter using next-generation sequencing. In buds sampled on January 10th and on February 7th in 2014, 6,978 and 7,096 genes, respectively, were significantly differentially expressed in the TH3 and 'Hengshanli' libraries. A comparative GO analysis revealed that oxidation-reduction process (biological process) and ATP binding (molecular function), were overrepresented during the ecodormancy period (EP) when compared to the endodormancy deepest period (DP), indicating that ATP synthesis was activated during the transition between these dormancy stages.

All-fiber Q-switched operation of thulium-doped silica fiber laser by piezoelectric microbending.

We demonstrate an all-fiber Q-switched laser operation in the 2 µm region on the basis of a dynamic periodic microbend and pulsed-pump configuration. A single-mode thulium-doped silica fiber is pumped by 1.6 µm-band laser diodes, and the dynamic loss is introduced in the fiber ring resonator by the periodic microbend that is electrically controlled with a piezoelectric actuator.