We report on fabrication of high-Q lithium niobate (LN) whispering-gallery-mode (WGM) microresonators suspended on silica pedestals by femtosecond laser direct writing followed by focused ion beam (FIB) milling. The micrometer-scale (diameter ~82 μm) LN resonator possesses a Q factor of ~2.5 × 10(5) around 1550 nm wavelength. The combination of femtosecond laser direct writing with FIB enables ...

Laser resonator configurations, which enable laser operation with two orthogonally polarized transverse modes, are presented. The intensity distributions of these two modes can be chosen to be complementary, so the gain medium can be exploited more efficiently than with a single mode, leading to improved output power. Moreover, the two modes can be combined and efficiently transformed into a si...

We report a technique to fabricate whispering gallery mode microdisk resonators using femtosecond laser micromachining and a heat reflow process to improve the optical quality of the resonator. The fabricated resonators had suppressed higher order modes with a measured Q-factor as high as 7.2× 10. The described fabrication process, which relies on material non-thermal laser ablation, offers the...

We present experimental results on the intracavity generation of radially polarized light by incorporation of a polarization-selective mirror in a CO(2)-laser resonator. The selectivity is achieved with a simple binary dielectric diffraction grating etched in the backsurface of the mirror substrate. Very high polarization selectivity was achieved, and good agreement of simulation and experiment...

A method of calculating the angular alignment tolerance of a Porro prism laser oscillator is presented. The reduction in mode volume due to misalignment is found by a ray optical approach. An analytical expression for alignment tolerance, in terms of resonator length L, prism azimuth angle theta, rod location L(2), and rod aperture radius alpha is obtained. An experiment was set up to measure t...

Phase locking of Brillouin backscattering Q-switched laser pulses that are much shorter than the round-trip time of the resonators has been demonstrated in a two-element fiber laser array. Despite the stochastic dynamics of nonlinear pulse generation, simultaneous generation and phase locking of short pulses have been achieved by using diffractive coupling and spatial filtering in an external r...

The JAERI superconducting rf linac has been developed to produce a high-power infrared free-electron laser (FEL). So far, a stable kW-level laser output has been achieved with improvements of the electron gun, the optical resonator as well as the beam transport optics. For increasing FEL power, energy-recovery experiments are planned in the next phase of the FEL development. The lattice design ...

The InnoSlab laser has the advantages of excellent thermal management and high overlapping efficiency. In this work, we report an with efficiency at 1319 nm end-pumped 0.6at.% Nd:YAG by 808 nm. hybrid stable–unstable resonator was adopted. For a cavity length 17.9 mm absorbed pumped power 423.5 W, output 81 W obtained T = 5%, exhibiting optical conversion 19.13% slope 29.80%.

In wireless optical communications, information is carried by coherent laser beams propagating through the free space. In realized communication channels, the standard beams created directly in the laser resonator are utilized. In recent time, an increasing attention has been focused on the so-called nondiffracting beams generated by auxiliary optical systems. In this paper, the theoretical and...

The second harmonic of the 842-nm output of a GaAlAs diode laser is generated in a KNbO(3) crystal in a resonant, external ring cavity. The diode laser is optically stabilized to the ring cavity through feedback from the counterpropagating fundamental wave, which is weakly excited in the resonator. We have produced 6.7 mW of tunable, narrowband radiation at 421 nm and have used that light to pe...