Yingying Ren

Mid-infrared waveguide lasers in rare-earth-doped YAG

We report near-infrared (IR) to mid-IR (up to 3.4 μm wavelength) multimode waveguiding in deep buried channel waveguides fabricated inside rare-earth ion-doped ceramic YAG for the first time to our knowledge. Waveguide laser operation at around 2 μm wavelength with multi- or single-transverse modes is also preliminarily demonstrated from these waveguides.

Swift nitrogen ion irradiated waveguide lasers in Nd:YAG crystal

We report on the fabrication, fluorescence and laser properties of optical waveguides by swift nitrogen ion irradiation in Nd:YAG crystals. The confocal micro-luminescence investigations have concluded that the fluorescence features of the bulk material have been well preserved in the waveguide. Under 808 nm optical end-pumping, continuous-wave (cw) laser oscillation at 1064.2 nm has been demonstrated with laser slope efficiencies of 16% and pump power thresholds of 38.3 mW.

Swift heavy-ion irradiated active waveguides in Nd:YAG crystals: fabrication and laser generation

An Nd:YAG planar waveguide laser has been fabricated by ultra-low-fluence (2×10(12) cm(-2)) swift heavy-ion irradiation (60 MeV Ar(4+) ions). The appearance of the buried waveguiding has been associated with an increased refractive index layer as a consequence of the ion-induced electronic damage. Continuous-wave laser oscillations at 1064.2 nm have been observed from the waveguide under 808 nm optical excitation, with the absorbed pump power at threshold and laser slope efficiency close to 26 mW and 5.9%, respectively.

Femtosecond-Laser-Inscribed BiB3O6 Nonlinear Cladding Waveguide for Second-Harmonic Generation

We report on the fabrication of a nonlinear cladding waveguide in BiB3O6 crystal by using femtosecond laser inscription. The waveguide (with a nearly circular cross section of 150 µm diameter) shows good guiding properties in two transverse polarizations. The guided-wave second-harmonic generation (SHG) at 532 nm green light has been realized under CW and pulsed wave pump at 1064 nm, based on the Type I birefringent phase matching configuration. The conversion efficiencies for CW and pulsed green laser SHG are 0.083 and 25%, respectively.

Mid-infrared waveguides in zinc sulfide crystal

Depressed cladding optical waveguides have been fabricated in a zinc sulfide (ZnS) crystal by femtosecond laser inscription. The structures support single- or multi-mode guidance at the mid-infrared wavelength of ~4 μm. The two-dimensional refractive index profiles of the single-mode waveguides have been reconstructed, and the modal profiles of TE and TM modes were calculated numerically, that show very good agreement with the measured near-field modal profiles. The minimum propagation losses of the multimode cladding waveguides at 4 μm were ~1.1 dB/cm for the TE polarization and ~1.3 dB/cm for the TM polarization.

Second harmonic generation of swift carbon ion irradiated Nd:GdCOB waveguides

We report on the second harmonic generation at ~532 nm of optical waveguides in Nd:GdCOB produced by swift carbon ion irradiation. The fabricated waveguide shows good guiding property. Under pump of ~1064-nm fundamental light, the optical conversion efficiency of the frequency doubling is 0.48% W(-1) and 6.8% W(-1) for continuous wave and pulsed laser beams, respectively.

Continuous wave channel waveguide lasers in Nd:LuVO4 fabricated by direct femtosecond laser writing.

Buried channel waveguides in Nd:LuVO<4 were fabricated by femtosecond laser writing with the double-line technique. The photoluminescence properties of the bulk materials were found to be well preserved within the waveguide core region. Continuous-wave laser oscillation at 1066.4 nm was observed from the waveguide under ~809 nm optical excitation, with the absorbed pump power at threshold and laser slope efficiency of 98 mW and 14%, respectively.

Guided-wave second harmonics in Nd:YCOB optical waveguides for integrated green lasers.

We report on guided-wave second-harmonic generations in nonlinear Nd:YCa4O(BO3)3 (Nd:YCOB) optical waveguides that are produced by the low-fluence swift Ar8+ ion irradiation. The guided-wave second harmonics are realized through the frequency doubling and the self-frequency-doubling of the waveguides under the optical pumps at wavelengths of 1064 and 810 nm, respectively. By virtue of the self-frequency-conversion configuration, the Nd:YCOB waveguides are promising candidates as novel, compact, miniature green laser sources.

Efficient laser emissions at 1.06 μm of swift heavy ion irradiated Nd:YCOB waveguides

We report on the fabrication of Nd:YCOB (Nd:YCa(4)O(BO(3))(3)) optical waveguides by using 170 MeVAr(8+) ion irradiation at an ultralow fluence of 2×10(12) ions/cm(2). The confocal microphotoluminescence investigation on the produced waveguides has shown the well-preserved fluorescence features within the guiding layer with respect to the bulks. Under the optical pump at wavelength of 810 nm, continuous wave waveguide lasers at 1061.2 nm have been generated at room temperature with a high slope efficiency of ~67.9%.

Continuous Wave Laser Generation in Proton Implanted Nd:GGG Planar Waveguides

We report on room temperature continuous wave laser generation at ~1062 nm from proton implanted Nd:GGG planar waveguides. Single-mode stable laser operation is realized with an 808-nm pump source, resulting in a laser threshold of ~49.3 mW and slope efficiency of 30%. The maximum output power of ~21.9 mW, an absorbed pump power of ~117.4 mW, leads to an optical-to-optical conversion efficiency of 18.7%.