OAM-mode coupling by segmented helical-ring-core waveguides inscribed with a femtosecond laser beam.

Azimuthally segmented helical-ring-core waveguides (HRCWs) were fabricated in silica glass by direct laser writing. Triple-segmented waveguides provided single-mode or few-mode light guidance depending on the core diameter. Bragg resonance reflection of the light carrying orbital angular momentum (OAM) was registered confirming the generalized angular phase-matching condition, which considers the azimuthally segmented structure of the waveguides.

Author Correction: Single shot laser writing with sub-nanosecond and nanosecond bursts of femtosecond pulses.

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Multilevel data writing in nanoporous glass by a few femtosecond laser pulses.

Multidimensional data recording inside nanoporous high-silica glass by a femtosecond laser beam has been investigated. It is shown that three femtosecond laser pulses at pulse repetition rates up to 1 MHz are sufficient for recording 3 bits of information inside nanoporous glass, which is an order of magnitude lower than the number of pulses required for data writing in silica glass and provides a corresponding gain in the data writing speed. Multilayer data recording and reading were demonstrated providing the storage density corresponding to the capacity of 25 GB in the optical compact disc form factor.

Single shot laser writing with sub-nanosecond and nanosecond bursts of femtosecond pulses.

A method is proposed for efficient laser modification of fused silica and sapphire by means of a burst of femtosecond pulses having time separation in the range 10-3000 ps. Modification enhancement with the pulse separation increase in the burst was observed on the tens picoseconds scale. It is proposed that accumulated transient tensile strain in the excitation region plays a crucial role in modification by a sub-nanosecond burst.

11-GHz waveguide Nd:YAG laser CW mode-locked with single-layer graphene.

We report stable, passive, continuous-wave (CW) mode-locking of a compact diode-pumped waveguide Nd:YAG laser with a single-layer graphene saturable absorber. The depressed cladding waveguide in the Nd:YAG crystal is fabricated with an ultrafast laser inscription method. The saturable absorber is formed by direct deposition of CVD single-layer graphene on the output coupler.

Low loss depressed cladding waveguide inscribed in YAG:Nd single crystal by femtosecond laser pulses.

A depressed cladding waveguide with record low loss of 0.12 dB/cm is inscribed in YAG:Nd(0.3at.

Waveguide-saturable absorber fabricated by femtosecond pulses in YAG:Cr(4+) crystal for Q-switched operation of Yb-fiber laser.

A waveguide-saturable absorber with low propagation loss is fabricated by femtosecond pulses in YAG:Cr(4+) crystal. Q-switch operation of a Yb fiber laser with the new saturable absorber having absorption saturation parameters similar to the bulk YAG:Cr(4+) crystal is demonstrated.

Near-infrared luminescence of RbPb2Cl5:Bi crystals.

A wideband near-IR (NIR) luminescence centered at 1080 nm was found in a RbPb(2)Cl(5):Bi single crystal grown by the Bridgman technique. Absorption, luminescence, and excitation of luminescence spectra were investigated at room and cryogenic temperatures. The luminescence was proposed to be due to the (3)P(1)-->(3)P(0) transition in Bi(+) ion.